S7 1200 Programmable Controller 2 System Manual

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S7-1200 Programmable controller

SIMATIC
S7
S7-1200 Programmable controller
System Manual

04/2011
A5E02486680-03

___________________
Preface
1
___________________
Product overview
STEP 7 programming
2
___________________
software
3
___________________
Installation
4
___________________
PLC concepts
5
___________________
Device configuration
6
___________________
Programming concepts
7
___________________
Basic instructions
8
___________________
Extended instructions
9
___________________
Data logging
10
___________________
Technology instructions
11
___________________
PROFINET and PROFIBUS
Communication processor
12
___________________
protocols
13
___________________
Web server
14
___________________
Online and diagnostic tools
A
___________________
Technical specifications
B
___________________
Calculating a power budget
C
___________________
Order numbers

Legal information
Legal information
Warning notice system
This manual contains notices you have to observe in order to ensure your personal safety, as well as to prevent
damage to property. The notices referring to your personal safety are highlighted in the manual by a safety alert
symbol, notices referring only to property damage have no safety alert symbol. These notices shown below are
graded according to the degree of danger.
DANGER
indicates that death or severe personal injury will result if proper precautions are not taken.
WARNING
indicates that death or severe personal injury may result if proper precautions are not taken.
CAUTION
with a safety alert symbol, indicates that minor personal injury can result if proper precautions are not taken.
CAUTION
without a safety alert symbol, indicates that property damage can result if proper precautions are not taken.
NOTICE
indicates that an unintended result or situation can occur if the corresponding information is not taken into
account.
If more than one degree of danger is present, the warning notice representing the highest degree of danger will
be used. A notice warning of injury to persons with a safety alert symbol may also include a warning relating to
property damage.

Qualified Personnel
The product/system described in this documentation may be operated only by personnel qualified for the specific
task in accordance with the relevant documentation for the specific task, in particular its warning notices and
safety instructions. Qualified personnel are those who, based on their training and experience, are capable of
identifying risks and avoiding potential hazards when working with these products/systems.

Proper use of Siemens products
Note the following:
WARNING
Siemens products may only be used for the applications described in the catalog and in the relevant technical
documentation. If products and components from other manufacturers are used, these must be recommended
or approved by Siemens. Proper transport, storage, installation, assembly, commissioning, operation and
maintenance are required to ensure that the products operate safely and without any problems. The permissible
ambient conditions must be adhered to. The information in the relevant documentation must be observed.

Trademarks
All names identified by ® are registered trademarks of the Siemens AG. The remaining trademarks in this
publication may be trademarks whose use by third parties for their own purposes could violate the rights of the
owner.

Disclaimer of Liability
We have reviewed the contents of this publication to ensure consistency with the hardware and software
described. Since variance cannot be precluded entirely, we cannot guarantee full consistency. However, the
information in this publication is reviewed regularly and any necessary corrections are included in subsequent
editions.

Siemens AG
Industry Sector
Postfach 48 48
90026 NÜRNBERG
GERMANY

order number: 6ES7298-8FA30-8BH0
Ⓟ 03/2011

Preface
Purpose of the manual
The S7-1200 series is a line of programmable logic controllers (PLCs) that can control a
variety of automation applications. Compact design, low cost, and a powerful instruction set
make the S7-1200 a perfect solution for controlling a wide variety of applications. The S71200 models and the Windows-based programming tool give you the flexibility you need to
solve your automation problems.
This manual provides information about installing and programming the S7-1200 PLCs and
is designed for engineers, programmers, installers, and electricians who have a general
knowledge of programmable logic controllers.

Required basic knowledge
To understand this manual, it is necessary to have a general knowledge of automation and
programmable logic controllers.

Scope of the manual
This manual describes the following products:
● STEP 7 V11 Basic and Professional
● S7-1200 CPU firmware release V2
For a complete list of the S7-1200 products described in this manual, refer to the technical
specifications (Page 561).

Certification, CE label, C-Tick, and other standards
Refer to the technical specifications (Page 561) for more information.

Service and support
In addition to our documentation, we offer our technical expertise on the Internet on the
customer support web site (http://www.siemens.com/automation/support-request).
Contact your Siemens distributor or sales office for assistance in answering any technical
questions, for training, or for ordering S7 products. Because your sales representatives are
technically trained and have the most specific knowledge about your operations, process
and industry, as well as about the individual Siemens products that you are using, they can
provide the fastest and most efficient answers to any problems you might encounter.

S7-1200 Programmable controller
System Manual, 04/2011, A5E02486680-03

Preface

Documentation and information
S7-1200 and STEP 7 provide a variety of documentation and other resources for finding the
technical information that you require.
● The S7-1200 system manual provides specific information about the operation,
programming and the specifications for the complete S7-1200 product family. In addition
to the system manual, the S7-1200 Easy Book provides a more general overview to the
capabilities of the S7-1200 family.
Both the system manual and the Easy Book are available as electronic (PDF) and printed
manuals. The electronic manuals can be downloaded from the customer support web site
and can also be found on the companion disk that ships with every S7-1200 CPU.
● The online information system of STEP 7 provides immediate access to the conceptual
information and specific instructions that describe the operation and functionality of the
programming package and basic operation of SIMATIC CPUs.
● My Documentation Manager accesses the electronic (PDF) versions of the SIMATIC
documentation set, including the system manual, the Easy Book and the information
system of STEP 7. With My Documentation Manager, you can drag and drop topics from
various documents to create your own custom manual.
The customer support entry portal (http://support.automation.siemens.com) provides a
link to My Documentation Manager under mySupport.
● The customer support web site also provides podcasts, FAQs, and other helpful
documents for S7-1200 and STEP 7. The podcasts utilize short educational video
presentations that focus on specific features or scenarios in order to demonstrate the
interactions, convenience and efficiency provided by STEP 7. Visit the following web sites
to access the collection of podcasts:
– STEP 7 Basic web page (http://www.automation.siemens.com/mcms/simaticcontroller-software/en/step7/step7-basic/Pages/Default.aspx)
– STEP 7 Professional web page (http://www.automation.siemens.com/mcms/simaticcontroller-software/en/step7/step7-professional/Pages/Default.aspx)
● You can also follow or join product discussions on the Service & Support technical forum
(https://www.automation.siemens.com/WW/forum/guests/Conferences.aspx?Language=e
n&siteid=csius&treeLang=en&groupid=4000002&extranet=standard&viewreg=WW&nodei
d0=34612486). These forums allow you to interact with various product experts.
– Forum for S7-1200
(https://www.automation.siemens.com/WW/forum/guests/Conference.aspx?SortField=
LastPostDate&SortOrder=Descending&ForumID=258&Language=en&onlyInternet=Fa
lse)
– Forum for STEP 7 Basic
(https://www.automation.siemens.com/WW/forum/guests/Conference.aspx?SortField=
LastPostDate&SortOrder=Descending&ForumID=265&Language=en&onlyInternet=Fa
lse)

S7-1200 Programmable controller

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Table of contents
Preface ...................................................................................................................................................... 3
1

Product overview ..................................................................................................................................... 17
1.1

Introducing the S7-1200 PLC.......................................................................................................17

1.2

Expansion capability of the CPU..................................................................................................20

1.3

S7-1200 modules.........................................................................................................................22

1.4

New features for S7-1200 and STEP 7 V11 ................................................................................23

1.5

Basic HMI panels .........................................................................................................................25

STEP 7 programming software................................................................................................................ 27
2.1

System requirements ...................................................................................................................27

2.2

Different views to make the work easier ......................................................................................28

2.3
2.3.1
2.3.2
2.3.3
2.3.4
2.3.5
2.3.6
2.3.7
2.3.8
2.3.9
2.3.10
2.3.11
2.3.12
2.3.13

Easy-to-use tools .........................................................................................................................29
Inserting instructions into your user program...............................................................................29
Accessing instructions from the "Favorites" toolbar.....................................................................29
Creating a complex equation with a simple instruction................................................................30
Adding inputs or outputs to a LAD or FBD instruction .................................................................32
Expandable instructions...............................................................................................................32
Selecting a version for an instruction...........................................................................................33
Modifying the appearance and configuration of STEP 7 .............................................................33
Dragging and dropping between editors......................................................................................34
Changing the operating mode of the CPU...................................................................................35
Capturing and restoring a block state ..........................................................................................35
Changing the call type for a DB ...................................................................................................36
Temporarily disconnecting devices from a network.....................................................................37
Virtual unplugging of devices from the configuration ...................................................................38

Installation ............................................................................................................................................... 39
3.1

Guidelines for installing S7-1200 devices....................................................................................39

3.2

Power budget ...............................................................................................................................40

3.3
3.3.1
3.3.2
3.3.3
3.3.4
3.3.5
3.3.6
3.3.7
3.3.8
3.3.8.1
3.3.8.2
3.3.8.3

Installation and removal procedures............................................................................................42
Mounting dimensions for the S7-1200 devices............................................................................42
Installing and removing the CPU .................................................................................................44
Installing and removing an SB or a CB........................................................................................45
Installing and removing an SM.....................................................................................................46
Installing and removing a CM or CP ............................................................................................48
Removing and reinstalling the S7-1200 terminal block connector...............................................49
Installing and removing the expansion cable...............................................................................50
TeleService ..................................................................................................................................52
Connecting the TeleService Adapter ...........................................................................................52
Installing the SIM card .................................................................................................................53
Installing the TS adapter unit .......................................................................................................54

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Table of contents

3.3.8.4

Installing the TS adapter on a wall.............................................................................................. 55

3.4

Wiring guidelines......................................................................................................................... 56

PLC concepts .......................................................................................................................................... 61
4.1
4.1.1
4.1.2
4.1.3
4.1.4
4.1.5
4.1.6
4.1.6.1
4.1.6.2

Execution of the user program .................................................................................................... 61
Operating modes of the CPU ...................................................................................................... 63
Processing the scan cycle in RUN mode.................................................................................... 65
Organization blocks (OBs) .......................................................................................................... 66
Event execution priorities and queuing ....................................................................................... 67
Monitoring the cycle time ............................................................................................................ 72
CPU memory............................................................................................................................... 74
System and clock memory .......................................................................................................... 76
Configuring the outputs on a RUN-to-STOP transition ............................................................... 78

4.2
4.2.1

Data storage, memory areas, I/O and addressing...................................................................... 78
Accessing the data of the S7-1200 ............................................................................................. 78

4.3

Processing of analog values ....................................................................................................... 83

4.4
4.4.1
4.4.2
4.4.3
4.4.4
4.4.5
4.4.6
4.4.7
4.4.7.1
4.4.7.2
4.4.7.3

Data types ................................................................................................................................... 84
Bool, Byte, Word, and DWord data types ................................................................................... 85
Integer data types ....................................................................................................................... 86
Floating-point real data types...................................................................................................... 86
Time and Date data types ........................................................................................................... 87
Data structure data type.............................................................................................................. 91
PLC data type ............................................................................................................................. 91
Pointer data types ....................................................................................................................... 91
"Pointer" pointer data type .......................................................................................................... 92
"Any" pointer data type................................................................................................................ 93
"Variant" pointer data type .......................................................................................................... 94

4.5
4.5.1
4.5.2
4.5.3
4.5.4

Using a memory card .................................................................................................................. 95
Inserting a memory card in the CPU........................................................................................... 96
Configuring the startup parameter of the CPU before copying the project to the memory
card ............................................................................................................................................. 97
Transfer card............................................................................................................................... 98
Program card ............................................................................................................................ 100

4.6

Recovery from a lost password................................................................................................. 102

Device configuration .............................................................................................................................. 103
5.1

Inserting a CPU......................................................................................................................... 104

5.2

Detecting the configuration for an unspecified CPU ................................................................. 105

5.3

Adding modules to the configuration......................................................................................... 106

5.4

Configuring the operation of the CPU ....................................................................................... 107

5.5

Configuring the parameters of the modules.............................................................................. 108

5.6
5.6.1
5.6.2
5.6.3
5.6.4
5.6.4.1

Configuring the CPU for communication................................................................................... 109
Creating a network connection ................................................................................................. 109
Configuring the Local/Partner connection path......................................................................... 110
Parameters for the PROFINET connection............................................................................... 113
Assigning Internet Protocol (IP) addresses............................................................................... 115
Assigning IP addresses to programming and network devices ................................................ 115
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System Manual, 04/2011, A5E02486680-03

Table of contents

5.6.4.2
5.6.4.3
5.6.4.4
5.6.5
5.6.6
5.6.7
5.6.8
6

Checking the IP address of your programming device ..............................................................117
Assigning an IP address to a CPU online..................................................................................117
Configuring an IP address for a CPU in your project.................................................................119
Testing the PROFINET network ................................................................................................121
Locating the Ethernet (MAC) address on the CPU....................................................................122
Configuring Network Time Protocol synchronization .................................................................123
PROFINET device start-up time, naming, and address assignment .........................................124

Programming concepts.......................................................................................................................... 127
6.1

Guidelines for designing a PLC system.....................................................................................127

6.2

Structuring your user program ...................................................................................................128

6.3
6.3.1
6.3.2
6.3.3
6.3.4

Using blocks to structure your program .....................................................................................129
Organization block (OB).............................................................................................................130
Function (FC) .............................................................................................................................132
Function block (FB)....................................................................................................................132
Data block (DB)..........................................................................................................................133

6.4

Understanding data consistency................................................................................................134

6.5
6.5.1
6.5.2
6.5.3

Programming language..............................................................................................................135
Ladder logic (LAD) .....................................................................................................................136
Function Block Diagram (FBD) ..................................................................................................137
EN and ENO for LAD and FBD..................................................................................................137

6.6
6.6.1
6.6.2
6.6.3

Protection ...................................................................................................................................138
Access protection for the CPU...................................................................................................138
Know-how protection .................................................................................................................139
Copy protection ..........................................................................................................................140

6.7

Downloading the elements of your program ..............................................................................142

6.8
6.8.1
6.8.2

Uploading from the CPU ............................................................................................................142
Copying elements of the project ................................................................................................142
Using the Synchronize function to upload .................................................................................143

6.9
6.9.1
6.9.2
6.9.3
6.9.4

Debugging and testing the program ..........................................................................................144
Monitor and modify data in the CPU..........................................................................................144
Watch tables and force tables....................................................................................................144
Cross reference to show usage .................................................................................................145
Call structure to examine the calling hierarchy ..........................................................................146

Basic instructions................................................................................................................................... 147
7.1
7.1.1
7.1.2
7.1.3

Bit logic.......................................................................................................................................147
Bit logic contacts and coils.........................................................................................................147
Set and reset instructions ..........................................................................................................150
Positive and negative edge instructions ....................................................................................152

7.2

Timers ........................................................................................................................................153

7.3

Counters.....................................................................................................................................161

7.4
7.4.1
7.4.2
7.4.3

Compare ....................................................................................................................................167
Compare ....................................................................................................................................167
In-range and Out-of-range instructions......................................................................................168
OK and Not OK instructions.......................................................................................................168

S7-1200 Programmable controller
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Table of contents

7.5
7.5.1
7.5.2
7.5.3
7.5.4
7.5.5
7.5.6
7.5.7
7.5.8
7.5.9

Math .......................................................................................................................................... 169
Calculate instruction.................................................................................................................. 169
Add, subtract, multiply and divide instructions .......................................................................... 170
Modulo instruction ..................................................................................................................... 171
Negation instruction .................................................................................................................. 172
Increment and decrement instructions...................................................................................... 173
Absolute value instruction ......................................................................................................... 173
Minimum and Maximum instructions......................................................................................... 174
Limit instruction ......................................................................................................................... 175
Floating-point math instructions ................................................................................................ 176

7.6
7.6.1
7.6.2
7.6.3
7.6.4

Move.......................................................................................................................................... 178
Move and block move instructions............................................................................................ 178
FieldRead and FieldWrite instructions ...................................................................................... 180
Fill instructions .......................................................................................................................... 181
Swap instruction........................................................................................................................ 182

7.7
7.7.1
7.7.2
7.7.3
7.7.4

Convert...................................................................................................................................... 183
CONV instruction ...................................................................................................................... 183
Round and truncate instructions ............................................................................................... 184
Ceiling and floor instructions ..................................................................................................... 185
Scale and normalize instructions .............................................................................................. 186

7.8
7.8.1
7.8.2
7.8.3
7.8.4
7.8.5
7.8.6
7.8.7

Program control......................................................................................................................... 189
Jump and label instructions....................................................................................................... 189
JMP_LIST instruction ................................................................................................................ 190
SWITCH instruction................................................................................................................... 191
RET execution control instruction ............................................................................................. 193
Re-trigger scan cycle watchdog instruction .............................................................................. 194
Stop scan cycle instruction........................................................................................................ 195
Get Error instructions ................................................................................................................ 195

7.9
7.9.1
7.9.2
7.9.3
7.9.4

Word logic operations ............................................................................................................... 199
AND, OR, and XOR instructions ............................................................................................... 199
Invert instruction........................................................................................................................ 199
Encode and decode instructions............................................................................................... 200
Select, Multiplex, and Demultiplex instructions......................................................................... 201

7.10
7.10.1
7.10.2

Shift and Rotate ........................................................................................................................ 204
Shift instructions........................................................................................................................ 204
Rotate instructions .................................................................................................................... 205

Extended instructions ............................................................................................................................ 207
8.1
8.1.1
8.1.2
8.1.3
8.1.4

Date and time-of-day................................................................................................................. 207
Date and time instructions......................................................................................................... 207
Set and read system clock ........................................................................................................ 209
Run-time meter instruction ........................................................................................................ 211
SET_TIMEZONE instruction ..................................................................................................... 212

8.2
8.2.1
8.2.2
8.2.3
8.2.3.1
8.2.3.2

String and character.................................................................................................................. 214
String data overview.................................................................................................................. 214
S_MOVE instruction .................................................................................................................. 214
String conversion instructions ................................................................................................... 215
String to value and value to string conversions ........................................................................ 215
String-to-characters and characters-to-string conversions ....................................................... 223

S7-1200 Programmable controller

System Manual, 04/2011, A5E02486680-03

Table of contents

8.2.3.3
8.2.4
8.2.4.1
8.2.4.2
8.2.4.3
8.2.4.4
8.2.4.5
8.2.4.6
8.2.4.7

ASCII to Hex and Hex to ASCII conversions .............................................................................224
String operation instructions ......................................................................................................226
LEN ............................................................................................................................................227
CONCAT ....................................................................................................................................227
LEFT, RIGHT, and MID .............................................................................................................228
DELETE .....................................................................................................................................230
INSERT ......................................................................................................................................231
REPLACE ..................................................................................................................................232
FIND...........................................................................................................................................233

8.3
8.3.1
8.3.2
8.3.3
8.3.4
8.3.5

Distributed I/O ............................................................................................................................234
RDREC and WRREC.................................................................................................................234
RALRM.......................................................................................................................................237
STATUS parameter for RDREC, WRREC, and RALRM...........................................................239
DPRD_DAT and DPWR_DAT....................................................................................................242
DPNRM_DG...............................................................................................................................244

8.4
8.4.1
8.4.2
8.4.2.1
8.4.2.2
8.4.3
8.4.4

Interrupts ....................................................................................................................................247
Attach and detach instructions...................................................................................................247
Cyclic interrupts..........................................................................................................................250
SET_CINT (Set cyclic interrupt) .................................................................................................250
QRY_CINT (Query cyclic interrupt)............................................................................................252
Time delay interrupts .................................................................................................................253
Asynchronous event interrupts ..................................................................................................255

8.5
8.5.1
8.5.2
8.5.3
8.5.4

Diagnostics.................................................................................................................................256
LED instruction...........................................................................................................................256
DeviceStates instruction ............................................................................................................257
ModuleStates instruction............................................................................................................258
GET_DIAG instruction................................................................................................................259

8.6
8.6.1
8.6.2
8.6.3

Pulse ..........................................................................................................................................261
CTRL_PWM instruction..............................................................................................................261
Operation of the pulse outputs...................................................................................................262
Configuring a pulse channel for PWM .......................................................................................264

8.7
8.7.1

Data block control ......................................................................................................................265
READ_DBL, WRIT_DBL (Read from or write to a DB in load memory) ....................................265

8.8

Common error codes for the "Extended" instructions................................................................267

Data logging .......................................................................................................................................... 269
9.1

Data log record structure ...........................................................................................................269

9.2
9.2.1
9.2.2
9.2.3
9.2.4
9.2.5

Program instructions that control Data logs...............................................................................270
DataLogCreate...........................................................................................................................270
DataLogOpen.............................................................................................................................273
DataLogClose ............................................................................................................................274
DataLogWrite .............................................................................................................................275
DataLogNewFile ........................................................................................................................277

9.3

Working with data logs...............................................................................................................279

9.4

Limits to the size of data log files ...............................................................................................280

9.5

Data log example program.........................................................................................................282

Technology instructions ......................................................................................................................... 287

S7-1200 Programmable controller
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Table of contents

10.1
10.1.1
10.1.2

High-speed counter................................................................................................................... 287
Operation of the high-speed counter ........................................................................................ 289
Configuration of the HSC .......................................................................................................... 295

10.2
10.2.1
10.2.2
10.2.3
10.2.4
10.2.5

PID control................................................................................................................................. 296
Inserting the PID instruction and technological object .............................................................. 297
PID_Compact instruction........................................................................................................... 299
PID_3STEP instruction.............................................................................................................. 302
Configuring the PID controller ................................................................................................... 309
Commissioning the PID controller............................................................................................. 311

10.3
10.3.1
10.3.2
10.3.2.1
10.3.2.2
10.3.2.3
10.3.2.4
10.3.2.5
10.3.2.6
10.3.2.7
10.3.2.8
10.3.3
10.3.3.1
10.3.3.2
10.3.3.3
10.3.3.4
10.3.4
10.3.5
10.3.5.1
10.3.5.2
10.3.5.3

Basic motion control.................................................................................................................. 312
Configuration of the axis ........................................................................................................... 314
Motion control instructions ........................................................................................................ 317
MC_Power instruction ............................................................................................................... 317
MC_Reset instruction ................................................................................................................ 320
MC_Home instruction................................................................................................................ 321
MC_Halt instruction ................................................................................................................... 323
MC_MoveAbsolute instruction .................................................................................................. 325
MC_MoveRelative instruction.................................................................................................... 327
MC_MoveVelocity instruction .................................................................................................... 329
MC_MoveJog instruction........................................................................................................... 331
Operation of motion control for S7-1200................................................................................... 333
CPU outputs used for motion control ........................................................................................ 333
Hardware and software limit switches for motion control.......................................................... 334
Homing ...................................................................................................................................... 337
Jerk limit .................................................................................................................................... 342
Commissioning.......................................................................................................................... 343
Monitoring active commands .................................................................................................... 346
Monitoring MC instructions with a "Done" output parameter .................................................... 346
Monitoring the MC_Velocity instruction..................................................................................... 350
Monitoring the MC_MoveJog instruction................................................................................... 354

PROFINET and PROFIBUS .................................................................................................................. 359
11.1

Number of asynchronous communication connections supported ........................................... 360

11.2
11.2.1
11.2.2
11.2.3
11.2.4
11.2.5
11.2.5.1
11.2.5.2
11.2.6
11.2.6.1
11.2.7
11.2.7.1
11.2.8
11.2.9
11.2.9.1
11.2.9.2
11.2.9.3
11.2.9.4

PROFINET ................................................................................................................................ 360
Local/Partner connection .......................................................................................................... 360
Connections and port IDs for the PROFINET instructions........................................................ 362
Protocols ................................................................................................................................... 364
Ad hoc mode ............................................................................................................................. 365
TCP and ISO on TCP................................................................................................................ 365
TSEND_C and TRCV_C ........................................................................................................... 366
TCON, TDISCON, TSEND, AND TRCV ................................................................................... 372
UDP........................................................................................................................................... 379
TUSEND and TURCV ............................................................................................................... 380
T_CONFIG ................................................................................................................................ 384
CONF_DATA Data block........................................................................................................... 386
Common parameters for instructions........................................................................................ 389
Communication with a programming device ............................................................................. 390
Establishing the hardware communications connection ........................................................... 390
Configuring the devices............................................................................................................. 391
Assigning Internet Protocol (IP) addresses............................................................................... 392
Testing your PROFINET network ............................................................................................. 392
S7-1200 Programmable controller

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Table of contents

11.2.10 HMI-to-PLC communication.......................................................................................................392
11.2.10.1 Configuring logical network connections between two devices............................................393
11.2.11 PLC-to-PLC communication ......................................................................................................394
11.2.11.1 Configuring logical network connections between two devices............................................395
11.2.11.2 Configuring the Local/Partner connection path between two devices..................................395
11.2.11.3 Configuring transmit (send) and receive parameters ...........................................................395
11.2.12 Configuring a CPU and PROFINET IO device ..........................................................................398
11.2.13 Diagnostics.................................................................................................................................401

11.3
11.3.1
11.3.1.1
11.3.1.2
11.3.1.3
11.3.1.4
11.3.2
11.3.2.1
11.3.2.2
11.3.2.3

PROFIBUS.................................................................................................................................402
Communications modules PROFIBUS ......................................................................................403
Connecting to PROFIBUS .........................................................................................................403
Communications services of the PROFIBUS CMs ....................................................................403
Other properties of the PROFIBUS CMs ...................................................................................405
Configuration examples for PROFIBUS ....................................................................................406
Configuring a DP master and slave device................................................................................407
Adding the CM 1243-5 (DP master) module and a DP slave ....................................................407
Configuring logical network connections between two PROFIBUS devices .............................408
Assigning PROFIBUS addresses to the CM 1243-5 module and DP slave..............................408

11.4
11.4.1
11.4.2
11.4.3

Distributed I/O ............................................................................................................................410
Distributed I/O Instructions.........................................................................................................410
Diagnostic instructions ...............................................................................................................410
Diagnostic events for distributed I/O ..........................................................................................411

11.5
11.5.1
11.5.2
11.5.3

S7 communication .....................................................................................................................412
GET and PUT instructions .........................................................................................................412
Creating an S7 connection.........................................................................................................415
Configuring the Local/Partner connection path between two devices .......................................416

11.6
11.6.1
11.6.2
11.6.3
11.6.4
11.6.5

Telecontrol and TeleService with the CP 1242-7 ......................................................................416
Connection to a GSM network ...................................................................................................416
Applications of the CP 1242-7 ...................................................................................................417
Other properties of the CP .........................................................................................................418
Accessories................................................................................................................................419
Configuration examples for telecontrol ......................................................................................420

Communication processor protocols...................................................................................................... 425
12.1

Using the RS232 and RS485 communication interfaces...........................................................425

12.2

Biasing and terminating an RS485 network connector..............................................................426

12.3
12.3.1
12.3.1.1
12.3.1.2
12.3.1.3
12.3.1.4
12.3.1.5
12.3.1.6
12.3.1.7
12.3.1.8
12.3.1.9
12.3.2
12.3.2.1

Point-to-Point (PtP) communication...........................................................................................427
Point-to-Point instructions ..........................................................................................................428
Common parameters for Point-to-Point instructions..................................................................428
PORT_CFG instruction ..............................................................................................................430
SEND_CFG instruction ..............................................................................................................431
RCV_CFG instruction.................................................................................................................433
SEND_PTP instruction...............................................................................................................437
RCV_PTP instruction .................................................................................................................440
RCV_RST instruction .................................................................................................................441
SGN_GET instruction.................................................................................................................442
SGN_SET instruction .................................................................................................................443
Configuring the communication ports ........................................................................................444
Managing flow control ................................................................................................................445

S7-1200 Programmable controller
System Manual, 04/2011, A5E02486680-03

Table of contents

12.3.3
12.3.3.1
12.3.3.2
12.3.4
12.3.4.1
12.3.5
12.3.5.1
12.3.5.2
12.3.5.3
12.3.5.4

Configuring the transmit (send) and receive parameters.......................................................... 447
Configuring transmit (send) parameters ................................................................................... 447
Configuring receive parameters................................................................................................ 448
Programming the PtP communications..................................................................................... 454
Polling architecture.................................................................................................................... 455
Example: Point-to-Point communication ................................................................................... 456
Configuring the communication module.................................................................................... 456
Programming the STEP 7 program........................................................................................... 458
Configuring the terminal emulator............................................................................................. 459
Running the example program.................................................................................................. 459

12.4
12.4.1
12.4.2
12.4.3
12.4.4
12.4.5
12.4.6
12.4.7

Universal serial interface (USS) communication....................................................................... 460
Requirements for using the USS protocol................................................................................. 461
USS_DRV instruction ................................................................................................................ 463
USS_PORT instruction.............................................................................................................. 466
USS_RPM instruction................................................................................................................ 467
USS_WPM instruction............................................................................................................... 468
USS status codes...................................................................................................................... 469
General drive setup information ................................................................................................ 471

12.5
12.5.1
12.5.2
12.5.3
12.5.4
12.5.5

Modbus communication ............................................................................................................ 474
MB_COMM_LOAD .................................................................................................................... 474
MB_MASTER ............................................................................................................................ 477
MB_SLAVE ............................................................................................................................... 482
Modbus master sample program .............................................................................................. 488
Modbus slave sample program................................................................................................. 489

Web server ............................................................................................................................................ 491
13.1

Enabling the Web server........................................................................................................... 492

13.2
Standard web pages ................................................................................................................. 492
13.2.1 Accessing the standard Web pages from the PC ..................................................................... 492
13.2.2 Layout of the standard Web pages ........................................................................................... 494
13.2.3 Introduction ............................................................................................................................... 495
13.2.4 Start........................................................................................................................................... 496
13.2.5 Identification .............................................................................................................................. 497
13.2.6 Diagnostic Buffer....................................................................................................................... 497
13.2.7 Module Information ................................................................................................................... 498
13.2.8 Communication ......................................................................................................................... 500
13.2.9 Variable Status.......................................................................................................................... 501
13.2.10 Data Logs .................................................................................................................................. 503
13.2.11 Constraints ................................................................................................................................ 504
13.2.11.1 Features restricted when JavaScript is disabled ................................................................. 505
13.2.11.2 Features restricted when cookies are not allowed............................................................... 506
13.2.11.3 Importing the Siemens security certificate ........................................................................... 506
13.2.11.4 Importing CSV format data logs to non-USA/UK versions of Microsoft Excel..................... 507
13.3
13.3.1
13.3.2
13.3.2.1
13.3.2.2
13.3.2.3
13.3.2.4

User-defined web pages ........................................................................................................... 508
Creating HTML pages ............................................................................................................... 509
AWP commands supported by the S7-1200 Web server ......................................................... 510
Reading variables ..................................................................................................................... 511
Writing variables........................................................................................................................ 512
Reading special variables ......................................................................................................... 513
Writing special variables ........................................................................................................... 514

S7-1200 Programmable controller

System Manual, 04/2011, A5E02486680-03

Table of contents

13.3.2.5 Using an alias for a variable reference ......................................................................................516
13.3.2.6 Defining enum types ..................................................................................................................516
13.3.2.7 Referencing CPU variables with an enum type .........................................................................517
13.3.2.8 Creating fragments ....................................................................................................................519
13.3.2.9 Importing fragments ...................................................................................................................520
13.3.2.10 Combining definitions ...........................................................................................................520
13.3.2.11 Handling tag names that contain special characters ............................................................521
13.3.3 Configuring use of user-defined Web pages .............................................................................522
13.3.4 Programming the WWW instruction for user-defined web pages..............................................524
13.3.5 Downloading the program blocks to the CPU............................................................................525
13.3.6 Accessing the user-defined web pages from the PC.................................................................526
13.3.7 Constraints specific to user-defined Web pages .......................................................................526
13.3.8 Example of a user-defined web page ........................................................................................527
13.3.8.1 Web page for monitoring and controlling a wind turbine ...........................................................527
13.3.8.2 Reading and displaying controller data......................................................................................529
13.3.8.3 Using an enum type ...................................................................................................................530
13.3.8.4 Writing user input to the controller .............................................................................................531
13.3.8.5 Writing a special variable ...........................................................................................................532
13.3.8.6 Reference: HTML listing of remote wind turbine monitor Web page .........................................532
13.3.8.7 Configuration in STEP 7 of the example Web page ..................................................................536
13.3.9 Setting up user-defined Web pages in multiple languages .......................................................537
13.3.9.1 Creating the folder structure ......................................................................................................538
13.3.9.2 Programming the language switch.............................................................................................538
13.3.9.3 Configuring STEP 7 to use a multi-language page structure ....................................................540
13.3.10 Advanced user-defined Web page control.................................................................................541
14

Online and diagnostic tools.................................................................................................................... 545
14.1

Status LEDs ...............................................................................................................................545

14.2

Going online and connecting to a CPU......................................................................................547

14.3

Assigning a name to a PROFINET IO device online .................................................................548

14.4

Setting the IP address and time of day......................................................................................549

14.5

CPU operator panel for the online CPU.....................................................................................550

14.6

Monitoring the cycle time and memory usage ...........................................................................550

14.7

Displaying diagnostic events in the CPU ...................................................................................551

14.8

Comparing and synchronizing offline and online CPUs ............................................................551

14.9
14.9.1
14.9.2
14.9.3
14.9.4
14.9.4.1
14.9.4.2
14.9.5
14.9.5.1
14.9.5.2

Monitoring and modifying values in the CPU.............................................................................552
Going online to monitor the values in the CPU..........................................................................553
Displaying status in the program editor .....................................................................................554
Capturing the online values of a DB to reset the start values....................................................554
Using a watch table to monitor and modify values in the CPU..................................................555
Using a trigger when monitoring or modifying PLC tags ...........................................................556
Enabling outputs in STOP mode................................................................................................557
Forcing values in the CPU .........................................................................................................558
Using the force table ..................................................................................................................558
Operation of the Force function .................................................................................................559

Technical specifications......................................................................................................................... 561
A.1

General Technical Specifications ..............................................................................................561

S7-1200 Programmable controller
System Manual, 04/2011, A5E02486680-03

Table of contents

A.2
A.2.1
A.2.2
A.2.3
A.2.3.1
A.2.3.2
A.2.3.3
A.2.4

CPU 1211C ............................................................................................................................... 566
General specifications and features.......................................................................................... 566
Digital inputs and outputs.......................................................................................................... 569
Analog inputs ............................................................................................................................ 571
Step response of the built-in analog inputs of the CPU ............................................................ 572
Sample time for the built-in analog ports of the CPU................................................................ 572
Measurement ranges of the analog inputs for voltage.............................................................. 572
Wiring diagrams ........................................................................................................................ 573

A.3
A.3.1
A.3.2
A.3.3
A.3.3.1
A.3.3.2
A.3.3.3
A.3.4

CPU 1212C ............................................................................................................................... 574
General specifications and features.......................................................................................... 574
Digital inputs and outputs.......................................................................................................... 577
Analog inputs ............................................................................................................................ 579
Step response of the built-in analog inputs of the CPU ............................................................ 580
Sample time for the built-in analog ports of the CPU................................................................ 580
Measurement ranges of the analog inputs for voltage.............................................................. 580
Wiring diagrams ........................................................................................................................ 581

A.4
A.4.1
A.4.2
A.4.3
A.4.3.1
A.4.3.2
A.4.3.3
A.4.4

CPU 1214C ............................................................................................................................... 582
General specifications and features.......................................................................................... 582
Digital inputs and outputs.......................................................................................................... 585
Analog inputs ............................................................................................................................ 587
Step response of the built-in analog inputs of the CPU ............................................................ 588
Sample time for the built-in analog ports of the CPU................................................................ 588
Measurement ranges of the analog inputs for voltage.............................................................. 588
CPU 1214C Wiring Diagrams ................................................................................................... 589

A.5
A.5.1
A.5.2
A.5.3
A.5.4

Digital signal modules (SMs)..................................................................................................... 590
SM 1221 Digital Input Specifications ........................................................................................ 590
SM 1222 Digital Output Specifications...................................................................................... 592
SM 1223 Digital Input/Output VDC Specifications .................................................................... 594
SM 1223 Digital Input/Output AC Specifications....................................................................... 597

A.6
A.6.1
A.6.2
A.6.3
A.6.4
A.6.5
A.6.6
A.6.7

Analog signal modules (SMs) ................................................................................................... 600
SM 1231 analog input module specifications............................................................................ 600
SM 1232 analog output module specifications ......................................................................... 602
SM 1234 analog input/output module specifications ................................................................ 603
Step response of the analog inputs .......................................................................................... 606
Sample time and update times for the analog inputs................................................................ 606
Measurement ranges of the analog inputs for voltage.............................................................. 607
Output (AQ) measurement ranges for voltage and current (SB and SM)................................. 607

A.7
A.7.1
A.7.1.1
A.7.1.2
A.7.2
A.7.2.1

Thermocouple and RTD signal modules (SMs) ........................................................................ 608
SM 1231 Thermocouple............................................................................................................ 608
Basic operation for a thermocouple .......................................................................................... 610
Selection tables for the SM 1231 thermocouple ....................................................................... 611
SM 1231 RTD ........................................................................................................................... 612
Selection tables for the SM 1231 RTD...................................................................................... 615

A.8
A.8.1
A.8.2
A.8.3
A.8.4

Digital signal boards (SBs)........................................................................................................ 617
SB 1221 200 kHz digital input specifications ............................................................................ 617
SB 1222 200 kHz digital output specifications .......................................................................... 619
SB 1223 200 kHz digital input / output specifications ............................................................... 621
SB 1223 2 X 24 VDC input / 2 X 24 VDC output specifications................................................ 623

A.9

Analog signal boards (SBs)....................................................................................................... 625
S7-1200 Programmable controller

System Manual, 04/2011, A5E02486680-03

Table of contents

A.9.1
A.9.2
A.9.3
A.9.3.1
A.9.3.2
A.9.3.3
A.9.3.4
A.9.4
A.9.4.1
A.9.4.2
A.9.5
A.9.5.1
A.9.5.2

SB 1231 1 analog input specifications.......................................................................................625
SB 1232 1 analog output specifications.....................................................................................627
Measurement ranges for analog inputs and outputs .................................................................629
Step response of the analog inputs ...........................................................................................629
Sample time and update times for the analog inputs ................................................................629
Measurement ranges of the analog inputs for voltage ..............................................................630
Output (AQ) measurement ranges for voltage and current (SB and SM)..................................630
Thermocouple SBs ....................................................................................................................631
SB 1231 1 analog thermocouple input specifications ................................................................631
Basic operation for a thermocouple ...........................................................................................633
RTD SBs ....................................................................................................................................635
SB 1231 1 analog RTD input specifications ..............................................................................635
Selection tables for the SB 1231 RTD .......................................................................................637

A.10
A.10.1
A.10.1.1
A.10.1.2
A.10.2
A.10.2.1
A.10.3
A.10.3.1
A.10.3.2
A.10.3.3

Communication interfaces .........................................................................................................640
PROFIBUS.................................................................................................................................640
CM 1242-5 .................................................................................................................................640
CM 1243-5 .................................................................................................................................641
GPRS .........................................................................................................................................643
CP 1242-7 ..................................................................................................................................644
RS232 and RS485 .....................................................................................................................646
CB 1241 RS485 Specifications..................................................................................................646
CM 1241 RS485 Specifications .................................................................................................648
CM 1241 RS232 Specifications .................................................................................................650

A.11

TeleService (TS Adapter and TS Adapter modular) ..................................................................651

A.12

SIMATIC memory cards.............................................................................................................651

A.13

Input simulators..........................................................................................................................652

A.14

I/O expansion cable ...................................................................................................................653

A.15
A.15.1
A.15.2

Companion products..................................................................................................................654
PM 1207 power module .............................................................................................................654
CSM 1277 compact switch module ...........................................................................................654

Calculating a power budget ................................................................................................................... 655

Order numbers ...................................................................................................................................... 659
C.1

CPU modules .............................................................................................................................659

C.2

Signal modules (SMs) and signal boards (SBs) ........................................................................659

C.3

Communication ..........................................................................................................................660

C.4

Other modules............................................................................................................................661

C.5

Memory cards ............................................................................................................................662

C.6

Basic HMI devices .....................................................................................................................662

C.7

Spare parts and other hardware ................................................................................................662

C.8

Programming software...............................................................................................................663

C.9

Documentation ...........................................................................................................................663

Index...................................................................................................................................................... 665

S7-1200 Programmable controller
System Manual, 04/2011, A5E02486680-03

Table of contents

S7-1200 Programmable controller

System Manual, 04/2011, A5E02486680-03

Product overview
1.1

Introducing the S7-1200 PLC
The S7-1200 controller provides the flexibility and power to control a wide variety of devices
in support of your automation needs. The compact design, flexible configuration, and
powerful instruction set combine to make the S7-1200 a perfect solution for controlling a
wide variety of applications.
The CPU combines a microprocessor, an integrated power supply, input and output circuits,
built-in PROFINET, high-speed motion control I/O, and on-board analog inputs in a compact
housing to create a powerful controller. After you download your program, the CPU contains
the logic required to monitor and control the devices in your application. The CPU monitors
the inputs and changes the outputs according to the logic of your user program, which can
include Boolean logic, counting, timing, complex math operations, and communications with
other intelligent devices.
Several security features help protect access to both the CPU and the control program:
● Every CPU provides password protection (Page 138) that allows you to configure access
to the CPU functions.
● You can use "know-how protection" (Page 139) to hide the code within a specific block.
● You can use copy protection (Page 140) to bind your program to a specific memory card
or CPU.
The CPU provides a PROFINET port for communication over a PROFINET network.
Additional modules are available for communicating over PROFIBUS, GPRS, RS485 or
RS232 networks.

① Power connector
② Memory card slot under top door
ཱ
③ Removable user wiring connectors

཰

ི

ཱི

(behind the doors)

④ Status LEDs for the on-board I/O
⑤ PROFINET connector (on the bottom of
the CPU)

ུ

S7-1200 Programmable controller
System Manual, 04/2011, A5E02486680-03

Product overview
1.1 Introducing the S7-1200 PLC
Table 1- 1

Comparing the CPU models

Feature

CPU 1211C

CPU 1212C

CPU 1214C

Physical size (mm)

90 x 100 x 75

110 x 100 x 75

Work

25 Kbytes

50 Kbytes

Load

1 Mbyte

2 Mbytes

Retentive

2 Kbytes

6 inputs/4 outputs

8 inputs/6 outputs

14 inputs/10 outputs

User memory

Local on-board I/O Digital
Analog

2 inputs

Inputs (I)

1024 bytes

Outputs (Q)

1024 bytes

Bit memory (M)

4096 bytes

8192 bytes

Signal module (SM) expansion

None

Signal board (SB) or communication
board (CB)

Communication module (CM)
(left-side expansion)

High-speed
counters

Total

Single phase

3 at 100 kHz

3 at 100 kHz
1 at 30 kHz

3 at 100 kHz
3 at 30 kHz

Quadrature phase

3 at 80 kHz

3 at 80 kHz
1 at 20 kHz

3 at 80 kHz
3 at 20 kHz

Pulse outputs1

Memory card

SIMATIC Memory card (optional)

Process image
size

Real time clock retention time

10 days, typical / 6 day minimum at 40 degrees C

PROFINET

1 Ethernet communications port

Real math execution speed

18 μs/instruction

Boolean execution speed

0.1 μs/instruction

For CPU models with relay outputs, you must install a digital signal board (SB) to use the pulse outputs.

The different CPU models provide a diversity of features and capabilities that help you create
effective solutions for your varied applications. For detailed information about a specific
CPU, see the technical specifications (Page 561).

S7-1200 Programmable controller

System Manual, 04/2011, A5E02486680-03

Product overview
1.1 Introducing the S7-1200 PLC
Table 1- 2

Blocks, timers and counters supported by S7-1200

Element
Blocks

Description
Type

OB, FB, FC, DB

Size

25 Kbytes (CPU 1211C and CPU 1212C)
50 Kbytes (CPU 1214C)

OBs

Timers

Counters

Quantity

Up to 1024 blocks total (OBs + FBs + FCs + DBs)

Address range for FBs, FCs,
and DBs

1 to 65535 (such as FB 1 to FB 65535)

Nesting depth

16 from the program cycle or start up OB; 4 from the time delay
interrupt, time-of-day interrupt, cyclic interrupt, hardware interrupt,
time error interrupt, or diagnostic error interrupt OB

Monitoring

Status of 2 code blocks can be monitored simultaneously

Program cycle

Multiple: OB 1, OB 200 to OB 65535

Startup

Multiple: OB 100, OB 200 to OB 65535

Time-delay interrupts and
cyclic interrupts

41 (1 per event): OB 200 to OB 65535

Hardware interrupts (edges
and HSC)

50 (1 per event): OB 200 to OB 65535

Time error interrupts

1: OB 80

Diagnostic error interrupts

1: OB 82

Type

IEC

Quantity

Limited only by memory size

Storage

Structure in DB, 16 bytes per timer

Type

IEC

Quantity

Limited only by memory size

Storage

Structure in DB, size dependent upon count type


SInt, USInt: 3 bytes



Int, UInt: 6 bytes



DInt, UDInt: 12 bytes

Time-delay and cyclic interrupts use the same resources in the CPU. You can have only a total of 4 of these interrupts
(time-delay plus cyclic interrupts). You cannot have 4 time-delay interrupts and 4 cyclic interrupts.

S7-1200 Programmable controller
System Manual, 04/2011, A5E02486680-03

Product overview
1.2 Expansion capability of the CPU

1.2

Expansion capability of the CPU
The S7-1200 family provides a variety of modules and plug-in boards for expanding the
capabilities of the CPU with additional I/O or other communication protocols. For detailed
information about a specific module, see the technical specifications (Page 561).

ཱི

ི
ཱ

཰

①
②
③
④
Table 1- 3

Communication module (CM), communcation processor (CP), or TS Adapter
CPU
Signal board (SB) or communication board (CB)
Signal module (SM)

Digital signal modules and signal boards

Type

Input only

③ digital SB



4 x 24VDC In,
200 kHz



4 x 24VDC Out,
200 kHz



4 x 5VDC In,
200 kHz



4 x 5VDC Out,
200 kHz

8 x 24VDC In




④ digital SM



16 x 24VDC In

Output only

Combination In/Out


2 x 24VDC In / 2 x 24VDC Out



2 x 24VDC In / 2 x 24VDC Out,
200 kHz



2 x 5VDC In / 2 x 5VDC Out,
200 kHz

8 x 24VDC Out



8 x 24VDC In / 8 x 24VDC Out

8 x Relay Out



8 x 24VDC In / 8 x Relay Out



8 x 120/230VAC In / 8 x Relay Out



16 x 24VDC Out



16 x 24VDC In / 16 x 24VDC Out



16 x Relay Out



16 x 24VDC In / 16 x Relay Out

S7-1200 Programmable controller

System Manual, 04/2011, A5E02486680-03

Product overview
1.2 Expansion capability of the CPU
Table 1- 4

Analog signal modules and signal boards

Type

Input only

③ analog SB



1 x 12 bit Analog In



1 x 16 bit RTD



1 x 16 bit Thermocouple



④ analog SM

Combination In/Out



1 x Analog Out

4 x Analog In



2 x Analog Out



8 x Analog In



4 x Analog Out



Thermocouple:



Table 1- 5

Output only

–

4 x 16 bit TC

–

8 x 16 bit TC

4 x Analog In / 2 x Analog Out

RTD:
–

4 x 16 bit RTD

–

8 x 16 bit RTD

Communication interfaces

Module

Type

Description

① Communication module (CM)

RS232

Full-duplex

RS485

Half-duplex

PROFIBUS Master

DPV1

PROFIBUS Slave

DPV1

① Communication processor (CP)

Modem connectivity

GPRS

① Communication board (CB)

RS485

Half-duplex

① TeleService

TS Adapter IE Basic1

Connection to CPU

TS Adapter GSM

GSM/GPRS

TS Adapter Modem

Modem

TS Adapter ISDN

ISDN

TS Adapter RS232

RS232

The TS Adapter allows you to connect various communication interfaces to the PROFINET port of the CPU. You install
the TS Adapter on the left side of the CPU and connect the TS Adapter modular (up to 3) onto the TS Adapter.

S7-1200 Programmable controller
System Manual, 04/2011, A5E02486680-03

Product overview
1.3 S7-1200 modules

1.3
Table 1- 6

S7-1200 modules
S7-1200 expansion modules

Type of module
The CPU supports one plug-in
expansion board:




A signal board (SB) provides
additional I/O for your CPU.
The SB connects on the front of
the CPU.

Description

཰

①

Status LEDs on
the SB

②

Removable user
wiring connector

①

Status LEDs

②

Bus connector

③

Removable user
wiring connector

①

Status LEDs

②

Communication
connector

ཱ

A communication board (CB)
allows you to add another
communication port to your
CPU.

Signal modules (SMs) add
additional functionality to the CPU.
SMs connect to the right side of the
CPU.


Digital I/O



Analog I/O



RTD and thermocouple

Communication modules (CMs)
and communications processors
(CPs) add communication options
to the CPU, such as for
PROFIBUS or RS232 / RS485
connectivity (for PtP, Modbus or
USS). A CP provides capabilities
for other types of communication,
such as to connect the CPU over a
GPRS network.


The CPU supports up to 3 CMs
or CPs



Each CM or CP connects to the
left side of the CPU (or to the
left side of another CM or CP)

཰
ཱ
ི

཰

ཱ

S7-1200 Programmable controller

System Manual, 04/2011, A5E02486680-03

Product overview
1.4 New features for S7-1200 and STEP 7 V11

1.4

New features for S7-1200 and STEP 7 V11
STEP 7 V11 and the S7-1200 CPU firmware V2 provide additional capabilities and features.
● To allow you more control of how you define the data in your user program, S7-1200
provides additional data types, such as pointers, indexed arrays, and structures.
● The instruction set has been expanded. New instructions include the following:
– Communication instructions include S7 communication GET and PUT instructions,
Distributed I/O RDREC, WRREC, and RALRM instructions, new PROFINET TUSEND
and TURCV instructions, and Teleservice GPRS and TM_MAIL instructions.
– A new Calculate instruction allows you to enter an equation directly into your LAD or
FBD program.
– Additional Interrupt instructions allow you to set and query time delay and cyclic
interrupts.
– You can also use the new diagnostic instructions to read the LED status or other
diagnostic information about modules and devices.
– There is also a new easy-to-use PID_3Step instruction.
● PROFINET UDP is now supported. UDP provides a "broadcast" communications
functionality.
● The S7-1200 CPU is a PROFINET IO controller.
● STEP 7 V11 provides an "undo" function.
● STEP 7 provides STOP and RUN buttons (Page 35) on the toolbar for stopping and
starting the CPU.
● The "force table' (Page 558) is separate from the watch table and allows you to force
inputs and outputs.
● You can copy-protect (Page 140) your user program or code blocks by binding them to a
specific CPU or memory card.
● You can capture and restore various states (Page 35) for your code blocks.
● You can capture the values of a DB (Page 554) to set those values as the start values.
● With a click of a button, you can export the data from tables in STEP 7 (such as a PLC
tag table or a watch table) into Microsoft Excel. You can also use CNTL-C and CNTL-V to
copy and paste between STEP 7 and Microsoft Excel.
● Disconnecting I/O devices (Page 37) from the configured network without losing the
configured device or having to reconfigure the network.
● Changing the assignment of a DB (Page 36) for an FB or an instruction (such as for
changing the association of an FB from a single-instance DB to a multi-instance DB).

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Product overview
1.4 New features for S7-1200 and STEP 7 V11

STEP 7 Basic and STEP 7 Professional programming packages
STEP 7 now provides two programming packages to provide the features you need.
● STEP 7 Basic provides all of the tools required for your S7-1200 project.
With the STEP 7 Basic package, you can connect your S7-1200 CPUs and the Basic HMI
panels onto a PROFINET network. By adding a communication module (CM),
communication processor (CP), or communication board (CB) to the device configuration
of the CPU, you can connect to other types of networks, such as PROFIBUS or RS485.
● STEP 7 Professional expands S7-1200 to include the world of S7-300 and S7-400. You
can now create networks using all of these SIMATIC controllers and I/O devices.

Web server functionality
To provide access to the CPU over the Internet, S7-1200 supports the S7 web server
functionality, with standard web pages stored in the CPU memory. You can also create your
own web pages for accessing data in the CPU.

Data logs
S7-1200 supports the creation of data log files to store process values. You use specific
DataLog instructions for creating and managing the data logs. The data log files are stored in
a standard CSV format, which can be opened with most spreadsheet applications.

New modules for the S7-1200
A variety of new modules expand the power of the S7-1200 CPU and to provide the flexibility
to meet your automation needs:
● New I/O signal modules (SMs) and signal boards (SBs) provide thermocouple (TC) and
RTD capability.
● New signal boards (SBs) provide high-speed (200 kHz) I/O.
● New communication modules (CMs) allow the S7-1200 to function as either a PROFIBUS
master or slave device.
● New communication interfaces support TeleService communication (modem, ISDN,
GSM/GPRS, and RS232).
● A new communication board (CB) plugs into the front of the CPU to provide RS485
functionality.

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Product overview
1.5 Basic HMI panels

1.5

Basic HMI panels
Because visualization is becoming a standard component for most machine designs, the
SIMATIC HMI Basic Panels provide touch-screen devices for basic operator control and
monitoring tasks. All panels have a protection rating for IP65 and have CE, UL, cULus, and
NEMA 4x certification.

Basic HMI Panel

KTP 400 Basic PN

Description

Technical data

4" touch screen with 4 tactile keys



250 tags



Mono (STN, gray scale)



50 process screens



76.79 mm x 57.59 mm (3.8")
Portrait or landscape



200 alarms



Resolution: 320 x 240



25 curves



32 KB recipe memory



5 recipes, 20 data records, 20 entries



500 tags



50 process screens



200 alarms



25 curves



32 KB recipe memory



5 recipes, 20 data records, 20 entries

6" touch screen with 6 tactile keys


Color (TFT, 256 colors) or Mono
(STN, gray scales)



115.2 mm x 86.4 mm (5.7")
Portrait or landscape



Resolution: 320 x 240

KTP 600 Basic PN
10" touch screen with 8 tactile keys



500 tags



Color (TFT, 256 colors)



50 process screens



211.2 mm x 158.4 mm (10.4")



200 alarms



Resolution: 640 x 480



25 curves



32 KB recipe memory



5 recipes, 20 data records, 20 entries

KTP 1000 Basic PN
15" touch screen



500 tags



Color (TFT, 256 colors)



50 process screens



304.1 mm x 228.1 mm (15.1")



200 alarms



Resolution: 1024 x 768



25 curves



32 KB recipe memory (integrated
flash)



5 recipes, 20 data records, 20 entries

TP 1500 Basic PN

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Product overview
1.5 Basic HMI panels

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STEP 7 programming software

STEP 7 provides a user-friendly environment to develop, edit, and monitor the logic needed
to control your application, including the tools for managing and configuring all of the devices
in your project, such as controllers and HMI devices. To help you find the information you
need, STEP 7 provides an extensive online help system.
STEP 7 provides standard programming languages for convenience and efficiency in
developing the control program for your application.
● LAD (ladder logic) is a graphical programming language. The representation is based on
circuit diagrams (Page 136).
● FBD (Function Block Diagram) is a programming language that is based on the graphical
logic symbols used in Boolean algebra (Page 137).
When you create a code block, you select the programming language to be used by that
block. Your user program can utilize code blocks created in any or all of the programming
languages.

2.1

System requirements
To install the STEP 7 software on a PC running Windows XP, or Windows 7 operating
system, you must log in with Administrator privileges.
Table 2- 1

System requirements

Hardware/software

Requirements

Processor type

Pentium M, 1.6 GHz or similar

RAM

1 GB

Available hard disk space

2 GB on system drive C:\

Operating systems



Windows XP Professional SP3



Windows 2003 Server R2 StdE SP2



Windows 7 (Professional, Enterprise, Ultimate)



Windows 2008 Server StdE SP2

Graphics card

32 MB RAM
24-bit color depth

Screen resolution

1024 x 768

Network

20 Mbit/s Ethernet or faster

Optical drive

DVD-ROM

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STEP 7 programming software
2.2 Different views to make the work easier

2.2

Different views to make the work easier
STEP 7 provides a user-friendly environment to develop controller logic, configure HMI
visualization, and setup network communication. To help increase your productivity, STEP 7
provides two different views of the project: a task-oriented set of portals that are organized
on the functionality of the tools (Portal view), or a project-oriented view of the elements within
the project (Project view). Choose which view helps you work most efficiently. With a single
click, you can toggle between the Portal view and the Project view.
Portal view

① Portals for the different tasks
② Tasks for the selected portal
③ Selection panel for the selected

action

④ Changes to the Project view

Project view

①
②
③
④
⑤
⑥
⑦

Menus and toolbar
Project navigator
Work area
Task cards
Inspector window
Changes to the Portal view
Editor bar

With all of these components in one place, you have easy access to every aspect of your
project. For example, the inspector window shows the properties and information for the
object that you have selected in the work area. As you select different objects, the inspector
window displays the properties that you can configure. The inspector window includes tabs
that allow you to see diagnostic information and other messages.
By showing all of the editors that are open, the editor bar helps you work more quickly and
efficiently. To toggle between the open editors, simply click the different editor. You can also
arrange two editors to appear together, arranged either vertically or horizontally. This feature
allows you to drag and drop between editors.

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STEP 7 programming software
2.3 Easy-to-use tools

2.3

Easy-to-use tools

2.3.1

Inserting instructions into your user program
STEP 7 provides task cards that contain the instructions for your
program. The instructions are grouped according to function.

To create your program, you drag instructions from the task card
onto a network.

2.3.2

Accessing instructions from the "Favorites" toolbar
STEP 7 provides a "Favorites" toolbar to give you quick access to the instructions that you
frequently use. Simply click the icon for the instruction to insert it into your network!
(For the "Favorites" in the instruction tree, doubleclick the icon.)
You can easily customize the
"Favorites" by adding new
instructions.
Simply drag and drop an
instruction to the "Favorites".
The instruction is now just a click
away!

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STEP 7 programming software
2.3 Easy-to-use tools

2.3.3

Creating a complex equation with a simple instruction
The Calculate instruction lets you create a math function that operates on multiple input
parameters to produce the result, according to the equation that you define.
In the Basic instruction tree, expand the Math functions folder.
Double-click the Calculate instruction to insert the instruction
into your user program.

The unconfigured Calculate
instruction provides two input
parameters and an output
parameter.
Click the "???" and select the data types for the input and output
parameters. (The input and output parameters must all be the same
data type.)
For this example, select the "Real" data type.

Click the "Edit equation" icon to enter the equation.

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STEP 7 programming software
2.3 Easy-to-use tools
For this example, enter the following equation for scaling a raw analog value. (The "In" and
"Out" designations correspond to the parameters of the Calculate instruction.)
Out value =
Out =
Where:

(Out high - Out low) /

(In high - In low) *

(In value - In low) +

(in4 - In5) /

(In2 - In3) *

(In1 - In3) +

Out low
In5

Out value

(Out)

Scaled output value

In value

(In1)

Analog input value

In high

(In2)

Upper limit for the scaled input value

In low

(In3)

Lower limit for the scaled input value

Out high

(In4)

Upper limit for the scaled output value

Out low

(In5)

Lower limit for the scaled ouput value

In the "Edit Calculate" box, enter the equation with the parameter names:
OUT = (in4 - In5) / (In2 - In3) * (In1 - In3) + In5

When you click "OK", the Calculate instruction creates the inputs required for the instruction.

Enter the tag names for the values that correspond to the parameters.

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STEP 7 programming software
2.3 Easy-to-use tools

2.3.4

Adding inputs or outputs to a LAD or FBD instruction
Some of the instructions allow you to create additional inputs or outputs.
● To add an input or output, click the "Create" icon or right-click on an input stub for one of
the existing IN or OUT parameters and select the "Insert input" or "Insert input"
command.
● To remove an input or output, right-click on the stub for one of the existing IN or OUT
parameters (when there are more than the original two inputs) and select the "Delete"
command.

2.3.5

Expandable instructions
Some of the more complex instructions are expandable, displaying only the key inputs and
outputs. To display the inputs and outputs, click the arrow at the bottom of the instruction.

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STEP 7 programming software
2.3 Easy-to-use tools

2.3.6

Selecting a version for an instruction
The development and release cycles for certain sets of instructions (such as Modbus, PID
and motion) have created multiple released versions for these instructions. To help ensure
compatibility and migration with older projects, STEP 7 allows you to choose which version
of instruction to insert into your user program.
Click the icon on the instruction tree task card to enable the
headers and columns of the instruction tree.
To change the version of the instruction, select the
appropriate version from the drop-down list.

2.3.7

Modifying the appearance and configuration of STEP 7
You can select a variety of settings, such as the
appearance of the interface, language, or the
directory for saving your work.
Select the "Settings" command from the
"Options" menu to change these settings.

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STEP 7 programming software
2.3 Easy-to-use tools

2.3.8

Dragging and dropping between editors
To help you perform tasks quickly and easily,
STEP 7 allows you to drag and drop elements
from one editor to another. For example, you
can drag an input from the CPU to the address
of an instruction in your user program.
You must zoom in at least 200% to select the
inputs or outputs of the CPU.
Notice that the tag names are displayed not
only in the PLC tag table, but also are
displayed on the CPU.

To display two editors at one time, use the
"Split editor" menu commands or buttons in
the toolbar.

To toggle between the editors that have been opened, click the icons in the editor bar.

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STEP 7 programming software
2.3 Easy-to-use tools

2.3.9

Changing the operating mode of the CPU
The CPU does not have a physical switch for changing the operating mode (STOP or RUN).
Use the "Start CPU" and "Stop CPU" toolbar buttons to change the operating
mode of the CPU.
When you configure the CPU in the device configuration, you configure the start-up behavior
in the properties of the CPU.
The "Online and diagnostics" portal also provides an operator panel for changing the
operating mode of the online CPU. To use the CPU operator panel, you must be connected
online to the CPU. The "Online tools" task card displays an operator panel that shows the
operating mode of the online CPU. The operator panel also allows you to change the
operating mode of the online CPU.
Use the button on the operator panel to change the operating mode
(STOP or RUN). The operator panel also provides an MRES button for
resetting the memory.

The color of the RUN/STOP indicator shows the current operating mode of the CPU. Yellow
indicates STOP mode, and green indicates RUN mode.

2.3.10

Capturing and restoring a block state
STEP 7 provides a means for capturing the state of a code block to create a benchmark or
reference point for the user program. A block state represents the status of a code block at a
specific time. Generating a block state allows you to reset the block to this state at any time,
discarding all changes you have since made. You can restore the user program to the state
of the block, even if you have made and saved changes to the program.
You can capture up to 10 block states in your project. Block states are still accessible after
the project has been saved. However, closing the project removes any captured block
states.
The ability to capture and restore the state of the program block is more powerful than the
"Undo" function because the block state transcends the "Save" function.
Click the "Capture block state" button to save the current state of the user program.
After you capture a state of the user program, the program block displays a "Block
state" icon.
Click the "Restore block state" button to restore the program block to the block state
that was captured.
Click the "Delete block state" button to remove the block state that was captured.

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STEP 7 programming software
2.3 Easy-to-use tools

2.3.11

Changing the call type for a DB
STEP 7 allows you to easily create or change the
association of a DB for an instruction or an FB that is in
an FB.
 You can switch the association between different DBs.
 You can switch the association between a singleinstance DB and a multi-instance DB.
 You can create an instance DB (if an instance DB is
missing or not available).
You can access the "Change call state" command either
by right-clicking the instruction or FB in the program
editor or by selecting the "Block call" command from the
"Options" menu.

The "Call options" dialog allows
you to select a single-instance
or multi-instance DB. You can
also select specific DBs from a
drop-down list of available DBs.

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STEP 7 programming software
2.3 Easy-to-use tools

2.3.12

Temporarily disconnecting devices from a network
You can disconnect individual network devices from the subnet. Because the configuration of
the device is not removed from the project, you can easily restore the connection to the
device.

Right-click the interface port of the network
device and select the "Disconnect from
subnet" command from the context menu.

STEP 7 reconfigures the network connections, but does not remove the disconnected device
from the project. While the network connection is deleted, the interface addresses are not
changed.

When you download the new network connections, the CPU goes to STOP mode.
To reconnect the device, simply create a new network connection to the port of the device.

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STEP 7 programming software
2.3 Easy-to-use tools

2.3.13

Virtual unplugging of devices from the configuration
STEP 7 provides a storage area for
"unplugged" modules. You can drag a
module from the rack to save the
configuration of that module. These
unplugged modules are saved with your
project, allowing you to reinsert the
module in the future without having to
reconfigure the parameters.
One use of this feature is for temporary
maintenance. Consider a scenario where
you might be waiting for a replacement
module and plan to temporarily use a
different module as a short-term
replacement. You could drag the
configured module from the rack to the
"Unplugged modules" and then insert the
temporary module.

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Installation
3.1

Guidelines for installing S7-1200 devices
The S7-1200 equipment is designed to be easy to install. You can install an S7-1200 either
on a panel or on a standard rail, and you can orient the S7-1200 either horizontally or
vertically. The small size of the S7-1200 allows you to make efficient use of space.
WARNING
The SIMATIC S7-1200 PLCs are Open Type Controllers. It is required that you install the
S7-1200 in a housing, cabinet, or electric control room. Entry to the housing, cabinet, or
electric control room should be limited to authorized personnel.
Failure to follow these installation requirements could result in death, severe personal injury
and/or property damage.
Always follow these requirements when installing S7-1200 PLCs.

Separate the S7-1200 devices from heat, high voltage, and electrical noise
As a general rule for laying out the devices of your system, always separate the devices that
generate high voltage and high electrical noise from the low-voltage, logic-type devices such
as the S7-1200.
When configuring the layout of the S7-1200 inside your panel, consider the heat-generating
devices and locate the electronic-type devices in the cooler areas of your cabinet. Reducing
the exposure to a high-temperature environment will extend the operating life of any
electronic device.
Consider also the routing of the wiring for the devices in the panel. Avoid placing low-voltage
signal wires and communications cables in the same tray with AC power wiring and highenergy, rapidly-switched DC wiring.

Provide adequate clearance for cooling and wiring
S7-1200 devices are designed for natural convection cooling. For proper cooling, you must
provide a clearance of at least 25 mm above and below the devices. Also, allow at least 25
mm of depth between the front of the modules and the inside of the enclosure.
CAUTION
For vertical mounting, the maximum allowable ambient temperature is reduced by 10
degrees C. Orient a vertically mounted S7-1200 system as shown in the following figure.
When planning your layout for the S7-1200 system, allow enough clearance for the wiring
and communications cable connections.
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Installation
3.2 Power budget
PP

ི

཰
PP

ཱི

ཱི
PP

ཱི

ཱ

ཱི

ཱི
PP

①
②

3.2

Side view
Horizontal installation

③
④

Vertical installation
Clearance area

Power budget
Your CPU has an internal power supply that provides power for the CPU, the signal
modules, signal board and communication modules and for other 24 VDC user power
requirements.
Refer to the technical specifications (Page 561) for information about the 5 VDC logic budget
supplied by your CPU and the 5 VDC power requirements of the signal modules, signal
boards, and communication modules. Refer to the "Calculating a power budget" (Page 655)
to determine how much power (or current) the CPU can provide for your configuration.
The CPU provides a 24 VDC sensor supply that can supply 24 VDC for input points, for relay
coil power on the signal modules, or for other requirements. If your 24 VDC power
requirements exceed the budget of the sensor supply, then you must add an external
24 VDC power supply to your system. Refer to the technical specifications (Page 561) for the
24 VDC sensor supply power budget for your particular CPU.
Note
The CM 1243-5 (PROFIBUS master module) requires power from the 24 VDC sensor supply
of the CPU.

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Installation
3.2 Power budget
If you require an external 24 VDC power supply, ensure that the power supply is not
connected in parallel with the sensor supply of the CPU. For improved electrical noise
protection, it is recommended that the commons (M) of the different power supplies be
connected.
WARNING
Connecting an external 24 VDC power supply in parallel with the 24 VDC sensor supply
can result in a conflict between the two supplies as each seeks to establish its own
preferred output voltage level.
The result of this conflict can be shortened lifetime or immediate failure of one or both
power supplies, with consequent unpredictable operation of the PLC system. Unpredictable
operation could result in death, severe personal injury and/or property damage.
The DC sensor supply and any external power supply should provide power to different
points.
Some of the 24 VDC power input ports in the S7-1200 system are interconnected, with a
common logic circuit connecting multiple M terminals. For example, the following circuits are
interconnected when designated as "not isolated" in the data sheets: the 24 VDC power
supply of the CPU, the power input for the relay coil of an SM, or the power supply for a nonisolated analog input. All non-isolated M terminals must connect to the same external
reference potential.
WARNING
Connecting non-isolated M terminals to different reference potentials will cause unintended
current flows that may cause damage or unpredictable operation in the PLC and any
connected equipment.
Failure to comply with these guidelines could cause damage or unpredictable operation
which could result in death or serve personal injury and/or property damage.
Always ensure that all non-isolated M terminals in an S7-1200 system are connected to the
same reference potential.

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Installation
3.3 Installation and removal procedures

3.3

Installation and removal procedures

3.3.1

Mounting dimensions for the S7-1200 devices
%

Table 3- 1

Mounting dimensions (mm)

S7-1200 Devices
CPU
Signal modules

Width A

Width B

CPU 1211C and CPU 1212C

90 mm

45 mm

CPU 1214C

110 mm

55 mm

Digital 8 and 16 point

45 mm

22.5 mm

70 mm

35 mm

30 mm

15 mm

60 mm 1

15 mm

Analog 2, 4, and 8 point
Thermocouple 4 and 8 point
RTD 4 point
Analog 16 point
RTD 8 point
Communication
interfaces

CM 1241 RS232 and CM 1241 RS485
CM 1243-5 PROFIBUS master and
CM 1242-5 PROFIBUS slave
CP 1242-7 GPRS
TS AdapterIE Basic

Because you must install a TS Adapter modular with the TS Adapter, the total width ("width A") is 60 mm.

Each CPU, SM, CM, and CP supports mounting on either a DIN rail or on a panel. Use the
DIN rail clips on the module to secure the device on the rail. These clips also snap into an
extended position to provide screw mounting positions to mount the unit directly on a panel.
The interior dimension of the hole for the DIN clips on the device is 4.3 mm.
A 25 mm thermal zone must be provided above and below the unit for free air circulation.

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Installation
3.3 Installation and removal procedures

Installing and removing the S7-1200 devices
The CPU can be easily installed on a standard DIN rail or on a panel. DIN rail clips are
provided to secure the device on the DIN rail. The clips also snap into an extended position
to provide a screw mounting position for panel-mounting the unit.

ཱི

ཱ

཰

①
②

DIN rail installation
DIN rail clip in latched position

ི

③
④

Panel installation
Clip in extended position for panel mounting

Before you install or remove any electrical device, ensure that the power to that equipment
has been turned off. Also, ensure that the power to any related equipment has been turned
off.
WARNING
Installation or removal of S7-1200 or related equipment with the power applied could cause
electric shock or unexpected operation of equipment.
Failure to disable all power to the S7-1200 and related equipment during installation or
removal procedures could result in death, severe personal injury and/or property damage
due to electric shock or unexpected equipment operation.
Always follow appropriate safety precautions and ensure that power to the S7-1200 is
disabled before attempting to install or remove S7-1200 CPUs or related equipment.
Always ensure that whenever you replace or install an S7-1200 device you use the correct
module or equivalent device.
WARNING
Incorrect installation of an S7-1200 module may cause the program in the S7-1200 to
function unpredictably.
Failure to replace an S7-1200 device with the same model, orientation, or order could result
in death, severe personal injury and/or property damage due to unexpected equipment
operation.
Replace an S7-1200 device with the same model, and be sure to orient and position it
correctly.

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Installation
3.3 Installation and removal procedures

3.3.2

Installing and removing the CPU
You can install the CPU on a panel or on a DIN rail.
Note
Attach any communication modules to the CPU and install the assembly as a unit. Install
signal modules separately after the CPU has been installed.
Consider the following when installing the units on the DIN rail or on a panel:
● For DIN rail mounting, make sure the upper DIN rail clip is in the latched (inner) position
and that the lower DIN rail clip is in the extended position for the CPU and attached CMs.
● After installing the devices on the DIN rail, move the lower DIN rail clips to the latched
position to lock the devices on the DIN rail.
● For panel mounting, make sure the DIN rail clips are pushed to the extended position.
To install the CPU on a panel, follow these steps:
1. Locate, drill, and tap the mounting holes (M4 or American Standard number 8), using the
dimensions shown in the mounting dimensions.
2. Ensure that the CPU and all S7-1200 equipment are disconnected from electrical power.
3. Extend the mounting clips from the module. Make sure the DIN rail clips on the top and
bottom of the CPU are in the extended position.
4. Secure the module to the panel, using screws placed into the clips.
Note
If your system is subject to a high vibration environment, or is mounted vertically, panel
mounting the S7-1200 will provide a greater level of protection.

Table 3- 2
Task

Installing the CPU on a DIN rail
Procedure
1. Install the DIN rail. Secure the rail to the mounting panel every 75 mm.
2. Ensure that the CPU and all S7-1200 equipment are disconnected from electrical
power.
3. Hook the CPU over the top of the DIN rail.
4. Pull out the DIN rail clip on the bottom of the CPU to allow the CPU to fit over the
rail.
5. Rotate the CPU down into position on the rail.
6. Push in the clips to latch the CPU to the rail.

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Installation
3.3 Installation and removal procedures
Table 3- 3

Removing the CPU from a DIN rail

Task

Procedure
1. Ensure that the CPU and all S7-1200 equipment are
disconnected from electrical power.
2. Disconnect the I/O connectors, wiring, and cables from
the CPU (Page 49).
3. Remove the CPU and any attached communication
modules as a unit. All signal modules should remain
installed.
4. If an SM is connected to the CPU, retract the bus
connector:
–

Place a screwdriver beside the tab on the top of the
signal module.

–

Press down to disengage the connector from the
CPU.

–

Slide the tab fully to the right.

5. Remove the CPU:

3.3.3
Table 3- 4

–

Pull out the DIN rail clip to release the CPU from the
rail.

–

Rotate the CPU up and off the rail, and remove the
CPU from the system.

Installing and removing an SB or a CB
Installing an SB or a CB

Task

Procedure
1. Ensure that the CPU and all S7-1200 equipment are disconnected
from electrical power.
2. Remove the top and bottom terminal block covers from the CPU.
3. Place a screwdriver into the slot on top of the CPU at the rear of the
cover.
4. Gently pry the cover up and remove it from the CPU.
5. Place the module straight down into its mounting position in the top
of the CPU.
6. Firmly press the module into position until it snaps into place.
7. Replace the terminal block covers.

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Installation
3.3 Installation and removal procedures
Table 3- 5

Removing an SB or a CB

Task

Procedure
1. Ensure that the CPU and all S7-1200 equipment are disconnected
from electrical power.
2. Remove the top and bottom terminal block covers from the CPU.
3. Place a screwdriver into the slot on top of the module.
4. Gently pry the module up to disengage it from the CPU.
5. Remove the module straight up from its mounting position in the top
of the CPU.
6. Replace the cover onto the CPU.
7. Replace the terminal block covers.

3.3.4
Table 3- 6
Task

Installing and removing an SM
Installing an SM
Procedure
Install your SM after installing the CPU.
1. Ensure that the CPU and all S7-1200 equipment are
disconnected from electrical power.
2. Remove the cover for the connector from the right side of the
CPU.
3. Insert a screwdriver into the slot above the cover.
4. Gently pry the cover out at its top and remove the cover.
Retain the cover for reuse.
Connect the SM to the CPU:
1. Position the SM beside the CPU.
2. Hook the SM over the top of the DIN rail.
3. Pull out the bottom DIN rail clip to allow the SM to fit over the
rail.
4. Rotate the SM down into position beside the CPU and push
the bottom clip in to latch the SM onto the rail.

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Installation
3.3 Installation and removal procedures

Task

Procedure
Extending the bus connector makes both mechanical and electrical connections for
the SM.
1. Place a screwdriver beside the tab on the top of the SM.
2. Slide the tab fully to the left to extend the bus connector into the CPU.
Follow the same procedure to install a signal module to a signal module.

Table 3- 7

Removing an SM

Task

Procedure
You can remove any SM without removing the CPU or other SMs in place.
1. Ensure that the CPU and all S7-1200 equipment are disconnected from
electrical power.
2. Remove the I/O connectors and wiring from the SM (Page 49).
3. Retract the bus connector.
–

Place a screwdriver beside the tab on the top of the SM.

–

Press down to disengage the connector from the CPU.

– Slide the tab fully to the right.
If there is another SM to the right, repeat this procedure for that SM.

Remove the SM:
1. Pull out the bottom DIN rail clip to release the SM from the rail.
2. Rotate the SM up and off the rail. Remove the SM from the system.
3. If required, cover the bus connector on the CPU to avoid contamination.
Follow the same procedure to remove a signal module from a signal module.

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Installation
3.3 Installation and removal procedures

3.3.5

Installing and removing a CM or CP
Attach any communication modules to the CPU and install the assembly as a unit, as shown
in Installing and removing the CPU (Page 44).

Table 3- 8

Installing a CM or CP

Task

Procedure
1. Ensure that the CPU and all S7-1200 equipment are
disconnected from electrical power.
2. Attach the CM to the CPU before installing the assembly
as a unit to the DIN rail or panel.
3. Remove the bus cover from the left side of the CPU:
–

Insert a screwdriver into the slot above the bus cover.

–

Gently pry out the cover at its top.

4. Remove the bus cover. Retain the cover for reuse.
5. Connect the CM or CP to the CPU:
–

Align the bus connector and the posts of the CM with
the holes of the CPU

–

Firmly press the units together until the posts snap into
place.

6. Install the CPU and CP on a DIN rail or panel.

Table 3- 9

Removing a CM or CP

Task

Procedure
Remove the CPU and CM as a unit from the DIN rail or panel.
1. Ensure that the CPU and all S7-1200 equipment are disconnected from electrical
power.
2. Remove the I/O connectors and all wiring and cables from the CPU and CMs.
3. For DIN rail mounting, move the lower DIN rail clips on the CPU and CMs to the
extended position.
4. Remove the CPU and CMs from the DIN rail or panel.
5. Grasp the CPU and CMs firmly and pull apart.

CAUTION
Do not use a tool to separate the modules because this will damage the units.

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Installation
3.3 Installation and removal procedures

3.3.6

Removing and reinstalling the S7-1200 terminal block connector
The CPU, SB and SM modules provide removable connectors to make connecting the wiring
easy.

Table 3- 10

Removing the connector

Task

Procedure
Prepare the system for terminal block connector removal by removing the power from the
CPU and opening the cover above the connector.
1. Ensure that the CPU and all S7-1200 equipment are disconnected from electrical power.
2. Inspect the top of the connector and locate the slot for the tip of the screwdriver.
3. Insert a screwdriver into the slot.
4. Gently pry the top of the connector away from the CPU. The connector will release with a
snap.
5. Grasp the connector and remove it from the CPU.

Table 3- 11

Installing the connector

Task

Procedure
Prepare the components for terminal block installation by removing power from the CPU and
opening the cover for connector.
1. Ensure that the CPU and all S7-1200 equipment are disconnected from electrical power.
2. Align the connector with the pins on the unit.
3. Align the wiring edge of the connector inside the rim of the connector base.
4. Press firmly down and rotate the connector until it snaps into place.
Check carefully to ensure that the connector is properly aligned and fully engaged.

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Installation
3.3 Installation and removal procedures

3.3.7

Installing and removing the expansion cable
The S7-1200 expansion cable provides additional flexibility in configuring the layout of your
S7-1200 system. Only one expansion cable is allowed per CPU system. You install the
expansion cable either between the CPU and the first SM, or between any two SMs.

Table 3- 12
Task

Installing and removing the male connector of the expansion cable
Procedure
To install the male connector:
1. Ensure that the CPU and all S7-1200 equipment are disconnected
from electrical power.
2. Push the connector into the bus connector on the right side of the
signal module or CPU.
To remove the male connector:
1. Ensure that the CPU and all S7-1200 equipment are disconnected
from electrical power.
2. Pull out the male connector to release it from the signal module or
CPU.

Table 3- 13
Task

Installing the female connector of the expansion cable
Procedure
1. Ensure that the CPU and all S7-1200 equipment
are disconnected from electrical power.
2. Place the female connector to the bus connector on
the left side of the signal module.
3. Slip the hook extension of the female connector
into the housing at the bus connector and press
down slightly to engage the hook.
4. Lock the connector into place:
–

Place a screwdriver beside the tab on the top of
the signal module.

– Slide the tab fully to the left.
To engage the connector, you must slide the connector
tab all the way to the left. The connector tab must be
locked into place.

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Installation
3.3 Installation and removal procedures

Table 3- 14

Removing the female connector of the expansion cable

Task

Procedure
1. Ensure that the CPU and all S7-1200 equipment are
disconnected from electrical power.
2. Unlock the connector:
–

Place a screwdriver beside the tab on the top of
the signal module.

–

Press down slightly and slide the tab fully to the
right.

3. Lift the connector up slightly to disengage the hook
extension.
4. Remove the female connector.

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Installation
3.3 Installation and removal procedures

3.3.8

TeleService

3.3.8.1

Connecting the TeleService Adapter
Before installing the TS Adapter IE Basic, you must first connect the TS Adapter and the
TS Adapter modular.
CAUTION
The TS Adapter modular can be damaged if you touch the contacts of the plug connector

④of the TS Adapter modular. Follow ESD guidelines in order to avoid damaging the

TS Adapter modular through electrostatic discharge. Before connecting the TS Adapter
modular and TS Adapter, make sure that both are in an idle state.

2
3
5

①
②
③

TS Adapter modular
TS Adapter
Elements

④
⑤
⑥

Plug connector from the TS Adapter modular
Cannot be opened
Ethernet port

CAUTION
Before connecting the TS Adapter modular and basic unit, ensure that the contact pins ④
are not bent. When connecting, ensure that the male connector and guide elements are
positioned correctly.
Only connect a TS Adapter modular onto a TS Adapter. Do not force a connection of a
TS Adapter to a different device, such as an S7-1200 CPU. Do not change the mechanical
construction of the connector, and do not remove or damage the guide elements.

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Installation
3.3 Installation and removal procedures

3.3.8.2

Installing the SIM card
Locate the SIM card slot on the underside of the TS Module GSM.
NOTICE
The SIM card may only be removed or inserted if the TS Module GSM is de-energized.

Table 3- 15

Installing the SIM card

Procedure

Task

Use a sharp object to press
the eject button of the SIM
card tray (in the direction of
the arrow) and remove the
SIM card tray.

Place the SIM card in the SIM
card tray as shown and put
the SIM card tray back into its
slot.
1

①

TS Module GSM

②

SIM card

③

SIM card tray

Note
Ensure that the SIM card tray is correctly oriented in the card tray. Otherwise, the SIM card
will not make connection with the module, and the eject button may not remove the card tray.

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Installation
3.3 Installation and removal procedures

3.3.8.3

Installing the TS adapter unit
Prerequisites: You must have connected the TS Adapter and TS Adapter modular together,
and the DIN rail must have been installed.
Note
If you install the TS unit vertically or in high-vibration environment, the TS Adapter modular
can become disconnected from the TS Adapter. Use an end bracket 8WA1 808 on the DIN
rail to ensure that the modules remain connected.

Table 3- 16

Installing and removing the TS Adapter

Task

Procedure
཰

Installation:
ཱ

1. Hook the TS Adapter with attached TS Adapter modular ① on the
DIN rail ②.
2. Rotate the unit back until it engages.
3. Push in the DIN rail clip on each module to attach the each module to
the rail.
Removal:
1. Remove the analog cable and Ethernet cable from the underside of
the TS Adapter.
2. Remove power from the TS Adapter.
3. Use a screwdriver to disengage the rail clips on both modules.
4. Rotate the unit upwards to remove the unit from the DIN rail.

WARNING
Before you remove power from the unit, disconnect the grounding of the TS Adapter by
removing the analog cable and Ethernet cable from the modules.

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Installation
3.3 Installation and removal procedures

3.3.8.4

Installing the TS adapter on a wall
Prerequisites: You must have connected the TS Adapter and TS Adapter modular.
1. Move the attachment slider ① to the backside of the TS Adapter and TS Adapter
modular in the direction of the arrow until it engages.
2. Screw the TS Adapter and TS Adapter modular to the position marked with ② to the
designated assembly wall.
The following illustration shows the TS Adapter from behind, with the attachment sliders ①
in both positions:
2

1
2

①
②

Attachment slider
Drill holes for wall mounting

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Installation
3.4 Wiring guidelines

3.4

Wiring guidelines
Proper grounding and wiring of all electrical equipment is important to help ensure the
optimum operation of your system and to provide additional electrical noise protection for
your application and the S7-1200. Refer to the technical specifications (Page 561) for the
S7-1200 wiring diagrams.

Prerequisites
Before you ground or install wiring to any electrical device, ensure that the power to that
equipment has been turned off. Also, ensure that the power to any related equipment has
been turned off.
Ensure that you follow all applicable electrical codes when wiring the S7-1200 and related
equipment. Install and operate all equipment according to all applicable national and local
standards. Contact your local authorities to determine which codes and standards apply to
your specific case.
WARNING
Installation or wiring the S7-1200 or related equipment with power applied could cause
electric shock or unexpected operation of equipment. Failure to disable all power to the S71200 and related equipment during installation or removal procedures could result in death,
severe personal injury, and/or damage due to electric shock or unexpected equipment
operation.
Always follow appropriate safety precautions and ensure that power to the S7-1200 is
disabled before attempting to install or remove the S7-1200 or related equipment.
Always take safety into consideration as you design the grounding and wiring of your S71200 system. Electronic control devices, such as the S7-1200, can fail and can cause
unexpected operation of the equipment that is being controlled or monitored. For this reason,
you should implement safeguards that are independent of the S7-1200 to protect against
possible personal injury or equipment damage.
WARNING
Control devices can fail in an unsafe condition, resulting in unexpected operation of
controlled equipment. Such unexpected operations could result in death, severe personal
injury and/or property damage.
Use an emergency stop function, electromechanical overrides, or other redundant
safeguards that are independent of the S7-1200.

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Installation
3.4 Wiring guidelines

Guidelines for isolation
S7-1200 AC power supply boundaries and I/O boundaries to AC circuits have been designed
and approved to provide safe separation between AC line voltages and low voltage circuits.
These boundaries include double or reinforced insulation, or basic plus supplementary
insulation, according to various standards. Components which cross these boundaries such
as optical couplers, capacitors, transformers, and relays have been approved as providing
safe separation. Isolation boundaries which meet these requirements have been identified in
S7-1200 product data sheets as having 1500 VAC or greater isolation. This designation is
based on a routine factory test of (2Ue + 1000 VAC) or equivalent according to approved
methods. S7-1200 safe separation boundaries have been type tested to 4242 VDC.
The sensor supply output, communications circuits, and internal logic circuits of an S7-1200
with included AC power supply are sourced as SELV (safety extra-low voltage) according to
EN 61131-2.
To maintain the safe character of the S7-1200 low voltage circuits, external connections to
communications ports, analog circuits, and all 24 V nominal power supply and I/O circuits
must be powered from approved sources that meet the requirements of SELV, PELV, Class
2, Limited Voltage, or Limited Power according to various standards.
WARNING
Use of non-isolated or single insulation supplies to supply low voltage circuits from an AC
line can result in hazardous voltages appearing on circuits that are expected to be touch
safe, such as communications circuits and low voltage sensor wiring.
Such unexpected high voltages could cause electric shock resulting in death, severe
personal injury and/or property damage.
Only use high voltage to low voltage power converters that are approved as sources of
touch safe, limited voltage circuits.

Guidelines for grounding the S7-1200
The best way to ground your application is to ensure that all the common and ground
connections of your S7-1200 and related equipment are grounded to a single point. This
single point should be connected directly to the earth ground for your system.
All ground wires should be as short as possible and should use a large wire size, such as 2
mm2 (14 AWG).
When locating grounds, consider safety-grounding requirements and the proper operation of
protective interrupting devices.

Guidelines for wiring the S7-1200
When designing the wiring for your S7-1200, provide a single disconnect switch that
simultaneously removes power from the S7-1200 CPU power supply, from all input circuits,
and from all output circuits. Provide over-current protection, such as a fuse or circuit breaker,
to limit fault currents on supply wiring. Consider providing additional protection by placing a
fuse or other current limit in each output circuit.

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Installation
3.4 Wiring guidelines
Install appropriate surge suppression devices for any wiring that could be subject to lightning
surges.
Avoid placing low-voltage signal wires and communications cables in the same wire tray with
AC wires and high-energy, rapidly switched DC wires. Always route wires in pairs, with the
neutral or common wire paired with the hot or signal-carrying wire.
Use the shortest wire possible and ensure that the wire is sized properly to carry the required
current. The CPU and SM connector accepts wire sizes from 2 mm2 to 0.3 mm2 (14 AWG to
22 AWG). The SB connector accepts wire sizes from 1.3 mm2 to 0.3 mm2 (16 AWG to 22
AWG). Use shielded wires for optimum protection against electrical noise. Typically,
grounding the shield at the S7-1200 gives the best results.
When wiring input circuits that are powered by an external power supply, include an
overcurrent protection device in that circuit. External protection is not necessary for circuits
that are powered by the 24 VDC sensor supply from the S7-1200 because the sensor supply
is already current-limited.
All S7-1200 modules have removable connectors for user wiring. To prevent loose
connections, ensure that the connector is seated securely and that the wire is installed
securely into the connector. To avoid damaging the connector, be careful that you do not
over-tighten the screws. The maximum torque for the CPU and SM connector screw is 0.56
N-m (5 inch-pounds). The maximum torque for the SB connector screw is 0.33 N-m (3 inchpounds).
To help prevent unwanted current flows in your installation, the S7-1200 provides isolation
boundaries at certain points. When you plan the wiring for your system, you should consider
these isolation boundaries. Refer to the technical specifications for the amount of isolation
provided and the location of the isolation boundaries. Do not depend on isolation boundaries
rated less than 1500 VAC as safety boundaries.

Guidelines for lamp loads
Lamp loads are damaging to relay contacts because of the high turn-on surge current. This
surge current will nominally be 10 to 15 times the steady state current for a Tungsten lamp.
A replaceable interposing relay or surge limiter is recommended for lamp loads that will be
switched a large number of times during the lifetime of the application.

Guidelines for inductive loads
You should equip inductive loads with suppression circuits to limit voltage rise when the
control output turns off. Suppression circuits protect your outputs from premature failure due
to the high voltages associated with turning off inductive loads. In addition, suppression
circuits limit the electrical noise generated when switching inductive loads. Placing an
external suppression circuit so that it is electrically across the load, and physically located
near the load is most effective in reducing electrical noise.

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Installation
3.4 Wiring guidelines
S7-1200 DC outputs include internal suppression circuits that are adequate for the inductive
loads in most applications. Since S7-1200 relay output contacts can be used to switch either
a DC or an AC load, internal protection is not provided.
Note
The effectiveness of a given suppression circuit depends on the application, and you must
verify it for your particular use. Always ensure that all components used in your suppression
circuit are rated for use in the application.

Typical suppressor circuit for DC or relay outputs that switch DC inductive loads

In most applications, the addition of a diode (A)
across a DC inductive load is suitable, but if your
application requires faster turn-off times, then the
addition of a Zener diode (B) is recommended. Be
sure to size your Zener diode properly for the amount
of current in your output circuit.

① 1N4001 diode or equivalent
② 8.2 V Zener (DC outputs),
36 V Zener (Relay outputs)

③ Output point
Typical suppressor circuit for relay outputs that switch AC inductive loads

MOV

When you use a relay output to switch 115 V/230
VAC loads, place the appropriately rated resistorcapacitor-metal oxide varistor (MOV) circuit across
the AC load. Ensure that the working voltage of the
MOV is at least 20% greater than the nominal line
voltage.

① 0.1 μ F
② 100 to 120 Ω
③ Output point

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Installation
3.4 Wiring guidelines

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PLC concepts
4.1

Execution of the user program
The CPU supports the following types of code blocks that allow you to create an efficient
structure for your user program:
● Organization blocks (OBs) define the structure of the program. Some OBs have
predefined behavior and start events, but you can also create OBs with custom start
events. Valid OB number ranges are shown in Event execution priorities and queuing
(Page 67).
● Functions (FCs) and function blocks (FBs) contain the program code that corresponds to
specific tasks or combinations of parameters. Each FC or FB provides a set of input and
output parameters for sharing data with the calling block. An FB also uses an associated
data block (called an instance DB) to maintain state of values between execution that can
be used by other blocks in the program. Valid FC and FB numbers range from 1 to
65535.
● Data blocks (DBs) store data that can be used by the program blocks. Valid DB numbers
range from 1 to 65535.
Execution of the user program begins with one or more optional start-up organization blocks
(OBs) which are executed once upon entering RUN mode, followed by one or more program
cycle OBs which are executed cyclically. An OB can also be associated with an interrupt
event, which can be either a standard event or an error event, and executes whenever the
corresponding standard or error event occurs.
A function (FC) or a function block (FB) is a block of program code that can be called from
an OB or from another FC or FB, down to the following nesting depths:
● 16 from the program cycle or startup OB
● 4 from time delay interrupt, cyclic interrupt, time of day interrupt, hardware interrupt, time
error interrupt, or diagnostic error interrupt OB
FCs are not associated with any particular data block (DB), while FBs are tied directly to a
DB and use the DB for passing parameters and storing interim values and results.
The size of the user program, data, and configuration is limited by the available load memory
and work memory in the CPU. There is no specific limit to the number of each individual OB,
FC, FB and DB block. However, the total number of blocks is limited to 1024.
Each cycle includes writing the outputs, reading the inputs, executing the user program
instructions, and performing background processing. The cycle is referred to as a scan cycle
or scan.

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PLC concepts
4.1 Execution of the user program
The modules (SM, SB, CB, CM or CP) are detected and logged in only upon power-up.
● Inserting or removing a module in the central rack under power (hot) is not supported.
Never insert or remove a module from the central rack when the CPU has power..
WARNING
Insertion or removal of a module (SM, SB, CD, CM or CP) from the central rack when
the CPU has power could cause unpredictable behavior, resulting in damage to
equipment and/or injury to personnel.
Always ensure that power is removed from the CPU and central rack before inserting or
removing a module from the central rack.
● You can insert or remove a SIMATIC memory card while the CPU is under power.
However, inserting or removing a memory card when the CPU is in RUN mode causes
the CPU to go to STOP mode.
CAUTION
Insertion or removal of a memory card when the CPU is in RUN mode causes the CPU
to go to STOP, which might result in in damage to the equipment or the process being
controlled.
Whenever you insert or remove a memory card, the CPU immediately goes to STOP
mode. Before inserting or removing a memory card, always ensure that the CPU is not
actively controlling a machine or process. Always install an emergency stop circuit for
your application or process.
● If you insert or remove a module in a distributed I/O rack (PROFINET or PROFIBUS)
when the CPU is in RUN mode, the CPU generates an entry in the diagnostics buffer and
stays in RUN mode.
Under the default configuration, all local digital and analog I/O points are updated
synchronously with the scan cycle using an internal memory area called the process image.
The process image contains a snapshot of the physical inputs and outputs (the physical I/O
points on the CPU, signal board, and signal modules).
The CPU performs the following tasks:
● The CPU writes the outputs from the process image output area to the physical outputs.
● The CPU reads the physical inputs just prior to the execution of the user program and
stores the input values in the process image input area. This ensures that these values
remain consistent throughout the execution of the user instructions.
● The CPU executes the logic of the user instructions and updates the output values in the
process image output area instead of writing to the actual physical outputs.
This process provides consistent logic through the execution of the user instructions for a
given cycle and prevents the flickering of physical output points that might change state
multiple times in the process image output area.

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PLC concepts
4.1 Execution of the user program
You can specify whether digital and analog I/O points are to be automatically updated and
stored in the process image. If you insert a module in the device view, its data is located in
the process image of the CPU (default). The CPU handles the data exchange between the
module and the process image area automatically during the update of the process image.
To remove digital or analog points from the process-image automatic update, select the
appropriate device in Device configuration, view the Properties tab, expand if necessary to
locate the desired I/O points, and then select "IO addresses/HW identifier". Then change the
entry for "Process image:" from "Cyclic PI" to "---". To add the points back to the processimage automatic update, change this selection back to "Cyclic PI".
You can immediately read physical input values and immediately write physical output
values when an instruction executes. An immediate read accesses the current state of the
physical input and does not update the process image input area, regardless of whether the
point is configured to be stored in the process image. An immediate write to the physical
output updates both the process image output area (if the point is configured to be stored in
the process image) and the physical output point. Append the suffix ":P" to the I/O address if
you want the program to immediately access I/O data directly from the physical point instead
of using the process image.
The CPU supports distributed I/O for both PROFINET and PROFIBUS networks (Page 359).

4.1.1

Operating modes of the CPU
The CPU has three modes of operation: STOP mode, STARTUP mode, and RUN mode.
Status LEDs on the front of the CPU indicate the current mode of operation.
● In STOP mode, the CPU is not executing the program. You can download a project.
● In STARTUP mode, the startup OBs (if present) are executed once. Interrupt events are
not processed during the startup mode.
● In RUN mode, the program cycle OBs are executed repeatedly. Interrupt events can
occur and be processed at any point within the RUN mode
You can only download a project while in STOP mode.
The CPU supports a warm restart for entering the RUN mode. Warm restart does not include
a memory reset. All non-retentive system and user data are initialized at warm restart.
Retentive user data is retained.
A memory reset clears all work memory, clears retentive and non-retentive memory areas,
and copies load memory to work memory. A memory reset does not clear the diagnostics
buffer or the permanently saved values of the IP address.
Note
When you download one or more DBs from STEP 7 V11 to an S7-1200 V2 CPU, the next
transition to RUN mode performs a warm restart and resets only the downloaded DBs to
their start values.
When you download project elements (such as device configuration, code blocks or DBs)
from STEP 7 V10.5 to any S7-1200 CPU or from STEP 7 V11 to an S7-1200 V1 CPU (or a
V2 CPU that has been configured as a V1 CPU), the next transition to RUN mode resets all
of the DBs in the project to their start values.

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You can specify the power-up mode and restart method of the CPU. This configuration item
appears under the "Device configuration" for the CPU under "Startup". When power is
applied, the CPU performs a sequence of power-up diagnostic checks and system
initialization. The CPU then enters the appropriate power-up mode. Certain detected errors
prevent the CPU from entering the RUN mode. The CPU supports the following power-up
modes:
● STOP mode
● Go to RUN mode after warm restart
● Go to previous mode after warm restart
You can change the current operating mode using the "STOP" or "RUN" commands
(Page 550) from the online tools of the programming software. You can also include a STP
instruction (Page 195) in your program to change the CPU to STOP mode. This allows you
to stop the execution of your program based on the program logic.

● In STOP mode, the CPU handles any communication requests (as appropriate) and
performs self-diagnostics. The CPU does not execute the user program, and the
automatic updates of the process image do not occur.
You can download your project only when the CPU is in STOP mode.
● In STARTUP and RUN modes, the CPU performs the tasks shown in the following figure.

ུ

(

཰

)

STARTUP
A

Clears the I (image) memory area

Initializes the outputs with either the
last value or the substitute value

Executes the startup OBs

Copies the state of the physical inputs
to I memory

Stores any interrupt events into the
queue to be processed after entering
RUN mode

Enables the writing of Q memory to the
physical outputs

ཱ

ི

ཱི

RUN

①
②
③
④
⑤

Writes Q memory to the physical outputs
Copies the state of the physical inputs to I
memory
Executes the program cycle OBs
Performs self-test diagnostics
Processes interrupts and communications
during any part of the scan cycle

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STARTUP processing
Whenever the operating state changes from STOP to RUN, the CPU clears the process
image inputs, initializes the process image outputs and processes the startup OBs. Any read
accesses to the process-image inputs by instructions in the startup OBs reads zero rather
than the current physical input value. Therefore, to read the current state of a physical input
during the startup mode, you must perform an immediate read. The startup OBs and any
associated FCs and FBs are executed next. If more than one startup OB exists, each is
executed in order according to the OB number, with the lowest OB number executing first.
Each startup OB includes startup information that helps you determine the validity of
retentive data and the time-of-day clock. You can program instructions inside the startup
OBs to examine these startup values and to take appropriate action. The following startup
locations are supported by the Startup OBs:
Table 4- 1

Startup locations supported by the startup OB

Input

Data Type

Description

LostRetentive

Bool

This bit is true if the retentive data storage areas have been lost

LostRTC

Bool

This bit is true if the time-of-day clock (Real time Clock) has been lost

The CPU also performs the following tasks during the startup processing.
● Interrupts are queued but not processed during the startup phase
● No cycle time monitoring is performed during the startup phase
● Configuration changes to HSC (high-speed counter), PWM (pulse-width modulation), and
PtP (point-to-point communication) modules can be made in startup
● Actual operation of HSC, PWM and point-to-point communication modules only occurs in
RUN
After the execution of the startup OBs finishes, the CPU goes to RUN mode and processes
the control tasks in a continuous scan cycle.

4.1.2

Processing the scan cycle in RUN mode
For each scan cycle, the CPU writes the outputs, reads the inputs, executes the user
program, updates communication modules, and responds to user interrupt events and
communication requests. Communication requests are handled periodically throughout the
scan.
These actions (except for user interrupt events) are serviced regularly and in sequential
order. User interrupt events which are enabled are serviced according to priority in the order
in which they occur.
The system guarantees that the scan cycle will be completed in a time period called the
maximum cycle time; otherwise a time error event is generated.

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● Each scan cycle begins by retrieving the current values of the digital and analog outputs
from the process image and then writing them to the physical outputs of the CPU, SB,
and SM modules configured for automatic I/O update (default configuration). When a
physical output is accessed by an instruction, both the output process image and the
physical output itself are updated.
● The scan cycle continues by reading the current values of the digital and analog inputs
from the CPU, SB, and SMs configured for automatic I/O update (default configuration),
and then writing these values to the process image. When a physical input is accessed
by an instruction, the value of the physical input is accessed by the instruction, but the
input process image is not updated.
● After reading the inputs, the user program is executed from the first instruction through
the end instruction. This includes all the program cycle OBs plus all their associated FCs
and FBs. The program cycle OBs are executed in order according to the OB number with
the lowest OB number executing first.
Communications processing occurs periodically throughout the scan, possibly interrupting
user program execution.
Self-diagnostic checks include periodic checks of the system and the I/O module status
checks.
Interrupts can occur during any part of the scan cycle, and are event-driven. When an event
occurs, the CPU interrupts the scan cycle and calls the OB that was configured to process
that event. After the OB finishes processing the event, the CPU resumes execution of the
user program at the point of interruption.

4.1.3

Organization blocks (OBs)
OBs control the execution of the user program. Each OB must have a unique OB number.
The default OB numbers are reserved below 200. Other OBs must be numbered 200 or
greater.
Specific events in the CPU trigger the execution of an organization block. OBs cannot call
each other or be called from an FC or FB. Only a start event, such as a diagnostic interrupt
or a time interval, can start the execution of an OB. The CPU handles OBs according to their
respective priority classes, with higher priority OBs executed before lower priority OBs. The
lowest priority class is 1 (for the main program cycle), and the highest priority class is 27 (for
the time-error interrupts).
OBs control the following operations:
● Program cycle OBs execute cyclically while the CPU is in RUN mode. The main block of
the program is a program cycle OB. This is where you place the instructions that control
your program and where you call additional user blocks. Multiple program cycle OBs are
allowed and are executed in numerical order. OB 1 is the default. Other program cycle
OBs must be identified as OB 200 or greater.
● Startup OBs execute one time when the operating mode of the CPU changes from STOP
to RUN, including powering up in the RUN mode and in commanded STOP-to-RUN
transitions. After completion, the main "Program cycle" OB will begin executing. Multiple
startup OBs are allowed. OB 100 is the default. Others must be OB 200 or greater.

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● Cyclic interrupt OBs execute at a specified interval. A cyclic interrupt OB will interrupt
cyclic program execution at user defined intervals, such as every 2 seconds. You can
configure up to a total of 4 for both the time-delay and cyclic events at any given time,
with one OB allowed for each configured time-delay and cyclic event. The OB must be
OB 200 or greater.
● Hardware interrupt OBs execute when the relevant hardware event occurs, including
rising and falling edges on built-in digital inputs and HSC events. A hardware interrupt OB
will interrupt normal cyclic program execution in reaction to a signal from a hardware
event. You define the events in the properties of the hardware configuration. One OB is
allowed for each configured hardware event. The OB must be OB 200 or greater.
● Time-error interrupt OBs execute when a time error is detected. A time-error interrupt OB
will interrupt normal cyclic program execution. OB 80 is the only OB number supported for
the time error event. You can configure the reaction of the CPU to a time error when
there is no OB 80 in your user program: The CPU can either stay in RUN (ignoring the
time error) or can change to STOP. There are two types of time errors handled by OB 80:
– Exceeding the maximum cycle time: You configure the maximum cycle time in the
properties of the CPU. The default configuration for exceeding the maximum time is to
set the CPU to STOP.
– Other time errors, such as starting a second cyclic interrupt before the CPU has
finished the execution of the first: The default configuration is for the CPU to stay in
RUN.
● Diagnostic error interrupt OBs execute when a diagnostic error is detected and reported.
A diagnostic OB interrupts the normal cyclic program execution if a diagnostics-capable
module recognizes an error (if the diagnostic error interrupt has been enabled for the
module). OB 82 is the only OB number supported for the diagnostic error event. You can
include an STP instruction (put CPU in STOP mode) inside your OB 82 if you desire your
CPU to enter STOP mode upon receiving this type of error. If there is no diagnostic OB in
the program, the CPU ignores the error (stays in RUN).

4.1.4

Event execution priorities and queuing
The CPU processing is controlled by events. An event triggers an interrupt OB to be
executed. You can specify the interrupt OB for an event during the creation of the block,
during the device configuration, or with an ATTACH or DETACH instruction. Some events
happen on a regular basis like the program cycle or cyclic events. Other events happen only
a single time, like the startup event and time delay events. Some events happen when there
is a change triggered by the hardware, such as an edge event on an input point or a high
speed counter event. There are also events like the diagnostic error and time error event
which only happen when there is an error. The event priorities, priority groups and queues
are used to determine the processing order for the event interrupt OBs.
The program cycle event happens once during each program cycle (or scan). During the
program cycle, the CPU writes the outputs, reads the inputs and executes program cycle
OBs. The program cycle event is required and is always enabled. You may have no program
cycle OBs, or you may have multiple OBs selected for the program cycle event. After the
program cycle event is triggered, the lowest numbered program cycle OB (usually OB 1) is
executed. The other program cycle OBs are executed sequentially (in numerical order) within
the program cycle.

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The cyclic interrupt events allow you to configure the execution of an interrupt OB at a
configured scan time. The initial scan time is configured when the OB is created and
selected to be a cyclic interrupt OB. A cyclic event will interrupt the program cycle and
execute the cyclic interrupt OB (the cyclic event is in a higher priority group than the program
cycle event).
Only one cyclic interrupt OB can be attached to a cyclic event.
Each cyclic event can be assigned a phase shift so that the execution of cyclic interrupts with
the same scan time can be offset from one another by the phase shift amount. The default
phase shift is 0. To change the initial phase shift, or to change the initial scan time for a
cyclic event, right click on the cyclic interrupt OB in the project tree, click "Properties", then
click "Cyclic interrupt", and enter the new initial values. You can also query and change the
scan time and the phase shift from your program using the Query cyclic interrupt
(QRY_CINT) and Set cyclic interrupt (SET_CINT) instructions. Scan time and phase shift
values set by the SET_CINT instruction do not persist through a power cycle or a transition
to STOP mode; scan time and phase shift values will return to the initial values following a
power cycle or a transition to STOP. The CPU supports a total of four cyclic and time-delay
interrupt events.
The startup event happens one time on a STOP to RUN transition and causes the startup
OBs to be executed. Multiple OBs can be selected for the startup event. The startup OBs are
executed in numerical order.
The time delay interrupt events allow you to configure the execution of an interrupt OB after
a specified delay time has expired. The delay time is specified with the SRT_DINT
instruction. The time delay events will interrupt the program cycle to execute the time delay
interrupt OB. Only one time delay interrupt OB can be attached to a time delay event. The
CPU supports four time delay events.
The hardware interrupt events are triggered by a change in the hardware, such as a rising or
falling edge on an input point, or a HSC (High Speed Counter) event. There can be one
interrupt OB selected for each hardware interrupt event. The hardware events are enabled in
Device configuration. The OBs are specified for the event in the Device configuration or with
an ATTACH instruction in the user program. The CPU supports several hardware interrupt
events. The exact events are based on the CPU model and the number of input points.
The time and diagnostic error interrupt events are triggered when the CPU detects an error.
These events are a higher priority group that the other interrupt events and can interrupt the
execution of the time delay, cyclic and hardware interrupt events. One interrupt OB can be
specified for each of the time error and diagnostic error interrupt events.

Understanding event execution priorities and queuing
The number of pending (queued) events from a single source is limited, using a different
queue for each event type. Upon reaching the limit of pending events for a given event type,
the next event is lost. Refer to the following section on "Understanding time error events" for
more information regarding queue overflows.
Each CPU event has an associated priority. You cannot change the priority of an OB. In
general, events are serviced in order of priority (highest priority first). Events of the same
priority are serviced on a "first-come, first-served" basis.

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Table 4- 2

OB events

Event

OB number

Quantity allowed

Start event

Program cycle

OB 1, OB 200 to
OB 65535

1 program cycle event



Startup OB ends

Multiple OBs allowed



Last program cycle OB ends

Startup

OB 100, OB 200 to
OB 65535

1 startup event 1, 2

STOP-to-RUN transition

Multiple OBs allowed

Time

OB 200 to OB 65535

Up to 4 time events3

Time-delay OB event is scheduled

1 OB per event

Cyclic OB event is scheduled

Edges:

Process

OB 200 to OB 65535

Up to 50 process

events4

1 OB per event



Rising edge events: 16 max.



Falling edge events: 16 max.

OB priority

For HSC:


CV=PV: 6 max.



Direction changed: 6 max.



External reset: 6 max.

Diagnostic error OB 82

1 event (only if OB 82 was
loaded)

Module transmits an error

Time error

1 event (only if OB 80 was
loaded)5



Maximum cycle time was
exceeded



A second time interrupt (cyclic or
time-delay) started before the
CPU had finished execution of
the first interrupt

OB 80

9
26

The startup event and the program cycle event will never occur at the same time because the startup event will run to
completion before the program cycle event will be started (controlled by the operating system).

Only the diagnostic error event (OB 82) interrupts the startup event. All other events are queued to be processed after
the startup event has finished.

The CPU provides a total of 4 time events that are shared by the time-delay OBs and the cyclic OBs. The number of
time-delay and cyclic OBs in your user program cannot exceed 4.

You can have more than 50 process events if you use the DETACH and ATTACH instructions.

You can configure the CPU to stay in RUN if the maximum scan cycle time was exceeded or you can use the
RE_TRIGR instruction to reset the cycle time. However, the CPU goes to STOP mode the second time that the
maximum scan cycle time was exceeded in one scan cycle.

After the execution of an OB with a priority of 2 to 25 has started, processing of that OB
cannot be interrupted by the occurrence of another event, except for by OB 80 (time-error
event, which has a priority of 26). All other events are queued for later processing, allowing
the current OB to finish.

Interrupt latency
The interrupt event latency (the time from notification of the CPU that an event has occurred
until the CPU begins execution of the first instruction in the OB that services the event) is
approximately 175 µsec, provided that a program cycle OB is the only event service routine
active at the time of the interrupt event.

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Understanding time error events
The occurrence of any of several different time error conditions results in a time error event.
The following time errors are supported:
● Maximum cycle time exceeded
● Requested OB cannot be started
● Queue overflow occurred
The maximum cycle time exceeded condition results if the program cycle does not complete
within the specified maximum scan cycle time. See the section on "Monitoring the cycle time"
(Page 72) for more information regarding the maximum cycle time condition, how to
configure the maximum scan cycle time, and how to reset the cycle timer.
The requested OB cannot be started condition results if an OB is requested by a cyclic
interrupt, a time-delay interrupt, or a time-of-day interrupt, but the requested OB is already
being executed.
The time-of-day (TOD) event missed or repeated condition results if one or more scheduled
interrupt times was skipped due to a change in the TOD clock setting or due to the CPU
being in the STOP mode.
The queue overflow occurred condition results if the interrupts are occurring faster than they
can be processed. The number of pending (queued) events is limited using a different queue
for each event type. If an event occurs when the corresponding queue is full, a time error
event is generated.
All time error events trigger the execution of OB 80 if it exists. If an OB 80 is not included in
the user program, then the device configuration of the CPU determines the CPU reaction to
the time error:
● The default configuration for time errors, such as starting a second cyclic interrupt before
the CPU has finished the execution of the first, is for the CPU to stay in RUN.
● The default configuration for exceeding the maximum time is for the CPU to change to
STOP.
You can use the RE_TRIGR instruction to reset the maximum cycle time. However, if two
"maximum cycle time exceeded" conditions occur within the same program cycle without
resetting the cycle timer, then the CPU transitions to STOP, regardless of whether OB 80
exists. See the section on "Monitoring the cycle time" (Page 72).
OB 80 includes startup information that helps you determine which event and OB generated
the time error. You can program instructions inside OB 80 to examine these startup values
and to take appropriate action.
Table 4- 3

Startup information for OB 80

Input

Data type

fault_id

BYTE

Description
16#01 - maximum cycle time exceeded
16#02 - requested OB cannot be started
16#07 and 16#09 - queue overflow occurred

csg_OBnr

OB_ANY

Number of the OB which was being executed when the error
occurred

csg_prio

UINT

Priority of the OB causing the error

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No time error interrupt OB 80 is present when you create a new project. If desired, you add a
time error interrupt OB 80 to your project by double-clicking "Add new block" under "Program
blocks" in the tree, then choose "Organization block", and then "Time error interrupt".

Understanding diagnostic error events
Analog (local), PROFINET, and PROFIBUS devices are capable of detecting and reporting
diagnostic errors. The occurrence or removal of any of several different diagnostic error
conditions results in a diagnostic error event. The following diagnostic errors are supported:
● No user power
● High limit exceeded
● Low limit exceeded
● Wire break
● Short circuit
Diagnostic error events trigger the execution of OB 82 if it exists. If OB 82 does not exist,
then the CPU ignores the error. No diagnostic error interrupt OB 82 is present when you
create a new project. If desired, you add a diagnostic error interrupt OB 82 to your project by
double-clicking "Add new block" under "Program blocks" in the tree, then choose
"Organization block", and then "Diagnostic error interrupt".
Note
Diagnostic errors for multi-channel local analog devices (I/O, RTD, and Thermocouple)
The OB 82 diagnostic error interrupt can report only one channel's diagnostic error at a time.
If two channels of a multi-channel device have an error, then the second error only triggers
OB 82 under the following conditions: the first channel error clears, the execution of OB 82
triggered by the first error is complete, and the second error still exists.
OB 82 includes startup information that helps you determine whether the event is due to the
occurrence or removal of an error, and the device and channel which reported the error. You
can program instructions inside OB 82 to examine these startup values and to take
appropriate action.

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Table 4- 4

Startup information for OB 82

Input

Data type

Description

IOstate

WORD

IO state of the device:


Bit 0 = 1 if the configuration is correct, and = 0 if the configuration is
no longer correct.



Bit 4 = 1 if an error is present (such as a wire break). (Bit 4 = 0 if
there is no error.)



Bit 5 = 1 if the configuration is not correct, and = 0 if the configuration
is correct again.



Bit 6 = 1 if an I/O access error has occurred. Refer to laddr for the
hardware identifier of the I/O with the access error. (Bit 6 = 0 if there
is no error.)

laddr

HW_ANY

Hardware identifier of the device or functional unit that reported the
error1

channel

UINT

Channel number

multierror

BOOL

TRUE if more than one error is present

The laddr input contains the hardware identifier of the device or functional unit which returned the error. The hardware
identifier is assigned automatically when components are inserted in the device or network view and appears in the
Constants tab of PLC tags. A name is also assigned automatically for the hardware identifier. These entries in the
Constants tab of the PLC tags cannot be changed.

4.1.5

Monitoring the cycle time
The cycle time is the time that the CPU operating system requires to execute the cyclic
phase of the RUN mode. The CPU provides two methods of monitoring the cycle time:
● Maximum scan cycle time
● Fixed minimum scan cycle time
Scan cycle monitoring begins after the startup event is complete. Configuration for this
feature appears under the "Device Configuration" for the CPU under "Cycle time".
The CPU always monitors the scan cycle and reacts if the maximum scan cycle time is
exceeded. If the configured maximum scan cycle time is exceeded, an error is generated
and is handled one of two ways:
● If the user program does not include an OB 80, then the CPU generates an error and
goes to STOP. (You can change the configuration of the CPU to ignore this time error
and stay in RUN. The default configuration is for the CPU to go to STOP.)
● If the user program includes an OB 80, then the CPU executes OB 80
The RE_TRIGR instruction (Re-trigger cycle time monitoring) allows you to reset the timer
that measures the cycle time. However, this instruction only functions if executed in a
program cycle OB; the RE_TRIGR instruction is ignored if executed in OB 80. If the
maximum scan cycle time is exceeded twice within the same program cycle with no
RE_TRIGR instruction execution between the two, then the CPU transitions to STOP
immediately. The use of repeated executions of the RE_TRIGR instruction can create an
endless loop or a very long scan.

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Typically, the scan cycle executes as fast as it can be executed and the next scan cycle
begins as soon as the current one completes. Depending upon the user program and
communication tasks, the time period for a scan cycle can vary from scan to scan. To
eliminate this variation, the CPU supports an optional fixed minimum scan cycle time (also
called fixed scan cycle). When this optional feature is enabled and a fixed minimum scan
cycle time is provided in ms, the CPU will maintain the minimum cycle time within ±1 ms for
the completion of each CPU scan.
In the event that the CPU completes the normal scan cycle in less time than the specified
minimum cycle time, the CPU spends the additional time of the scan cycle performing
runtime diagnostics and/or processing communication requests. In this way the CPU always
takes a fixed amount of time to complete a scan cycle.
In the event that the CPU does not complete the scan cycle in the specified minimum cycle
time, the CPU completes the scan normally (including communication processing) and does
not create any system reaction as a result of exceeding the minimum scan time. The
following table defines the ranges and defaults for the cycle time monitoring functions.
Table 4- 5

Range for the cycle time

Cycle time

Range (ms)

Default

Maximum scan cycle time1

1 to 6000

150 ms

Fixed minimum scan cycle time2

1 to maximum scan cycle time

Disabled

The maximum scan cycle time is always enabled. Configure a cycle time between 1 ms to 6000 ms. The default is 150
ms.

The fixed minimum scan cycle time is optional, and is disabled by default. If required, configure a cycle time between 1
ms and the maximum scan cycle time.

Configuring the cycle time and communication load
You use the CPU properties in the Device configuration to configure the following
parameters:
● Cycle time: You can enter a maximum scan cycle time. You can also enter a fixed
minimum scan cycle time.

● Communications load: You can configure a percentage of the time to be dedicated for
communication tasks.

For more information about the scan cycle, see "Monitoring the cycle time". (Page 72)

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4.1.6

CPU memory

Memory management
The CPU provides the following memory areas to store the user program, data, and
configuration:
● Load memory is non-volatile storage for the user program, data and configuration. When
a project is downloaded to the CPU, it is first stored in the Load memory area. This area
is located either in a memory card (if present) or in the CPU. This non-volatile memory
area is maintained through a power loss. The memory card supports a larger storage
space than that built-in to the CPU.
● Work memory is volatile storage for some elements of the user project while executing
the user program. The CPU copies some elements of the project from load memory into
work memory. This volatile area is lost when power is removed, and is restored by the
CPU when power is restored.
● Retentive memory is non-volatile storage for a limited quantity of work memory values.
The retentive memory area is used to store the values of selected user memory locations
during power loss. When a power down occurs, the CPU has enough hold-up time to
retain the values of a limited number of specified locations. These retentive values are
then restored upon power up.
To display the memory usage for the current project, right-click the CPU (or one of its blocks)
and select "Resources" from the context. To display the memory usage for the current CPU,
double-click "Online and diagnostics", expand "Diagnostics", and select "Memory".

Retentive memory
Data loss after power failure can be avoided by marking certain data as retentive. The
following data can be configured to be retentive:
● Bit memory(M): You can define the precise width of the memory for bit memory in the
PLC tag table or in the assignment list. Retentive bit memory always starts at MB0 and
runs consecutively up through a specified number of bytes. Specify this value from the
PLC tag table or in the assignment list by clicking the "Retain" toolbar icon. Enter the
number of M bytes to retain starting at MB0.
● Tags of a function block (FB): If an FB was created with the "Symbolic access only" box
selected, then the interface editor for this FB includes a "Retain" column. In this column,
you can select either "Retain" or "Non-Retain" individually for each tag. An instance DB
that was created when this FB is placed in the program editor shows this retain column
as well, but only for display; you cannot change the retentive state from within the
instance DB interface editor for an FB that was configured to be "Symbolic access only".
If an FB was created with the "Symbolic access only" box deselected, then the interface
editor for this FB does not include a "Retain" column. An instance DB created when this
FB is inserted in the program editor shows a "Retain" column which is available for edit.
In this case, selecting the "Retain" option for any tag results in all tags being selected.
Similarly, deselecting the option for any tag results in all tags being deselected. For an FB
that was configured to not be "Symbolic access only", you can change the retentive state
from within the instance DB editor, but all tags are set to the same retentive state
together.

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After you create the FB, you cannot change the option for "symbolic access only". This
option can only be selected when the FB is created. To determine whether an existing FB
was configured for "symbolic access only", right-click the FB in the Project tree, select
"Properties", and then select "Attributes".
● Tags of a global data block: The behavior of a global DB with regard to retentive state
assignment is similar to that of an FB. Depending on the setting for symbolic addressing
you can define the retentive state either for individual or for all tags of a global data block.
– If the "Symbolic access only" attribute of the DB is checked, the retentive state can be
set for each individual tag.
– If the "Symbolic access only" attribute of the DB is un-checked, the retentive-state
setting applies to all tags of the DB; either all tags are retentive or no tag is retentive.
A total of 2048 bytes of data can be retentive. To see how much is available, from the PLC
tag table or the assignment list, click on the "Retain" toolbar icon. Although this is where the
retentive range is specified for M memory, the second row indicates the total remaining
memory available for M and DB combined.

Diagnostics buffer
The CPU supports a diagnostic buffer which contains an entry for each diagnostic event.
Each entry includes a date and time the event occurred, an event category, and an event
description. The entries are displayed in chronological order with the most recent event at
the top. While the CPU maintains power, up to 50 most recent events are available in this
log. When the log is full, a new event replaces the oldest event in the log. When power is
lost, the ten most recent events are saved.
The following types of events are recorded in the diagnostics buffer:
● Each system diagnostic event; for example, CPU errors and module errors
● Each state change of the CPU (each power up, each transition to STOP, each transition
to RUN)
To access the diagnostic buffer, you must be online. Locate the log under "Online &
diagnostics / Diagnostics / Diagnostics buffer". For more information regarding
troubleshooting and debugging, refer to the "Online and diagnostics" chapter (Page 551).

Time of day clock
The CPU supports a time-of-day clock. A super-capacitor supplies the energy required to
keep the clock running during times when the CPU is powered down. The super-capacitor
charges while the CPU has power. After the CPU has been powered up at least 24 hours,
then the super-capacitor has sufficient charge to keep the clock running for typically 10 days.
The Time of Day Clock is set to system time, which is Coordinated Universal Time (UTC).
STEP 7 sets the Time of Day Clock to system time. There are instructions to read the
system time (RD_SYS_T) or local time (RD_LOC_T). Local time is calculated by using the
time zone and daylight saving time offsets that you set in the CPU Clock device
configuration.

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Configure the time-of-day clock for the CPU under the "Time of day" property. You can also
enable daylight saving time and specify the start and end times for daylight saving time. To
set the time-of-day clock, you must be online and in the "Online & diagnostics" view of the
CPU. Use the "Set time of day" function.

4.1.6.1

System and clock memory
You use the CPU properties to enable bytes for "system memory" and "clock memory". Your
program logic can reference the individual bits of these functions.
● You can assign one byte in M memory for system memory. The byte of system memory
provides the following four bits that can be referenced by your user program:
– "Always 0 (low)" bit is always set to 0.
– "Always 1 (high)" bit is always set to 1.
– "Diagnostic graph changed" is set to 1 for one scan after the CPU logs a diagnostic
event. Because the CPU does not set the "diagnostic graph changed" bit until the end
of the first execution of the program cycle OBs, your user program cannot detect if
there has been a diagnostic change either during the execution of the startup OBs or
the first execution of the program cycle OBs.
– "First scan" bit is set to1 for the duration of the first scan after the startup OB finishes.
(After the execution of the first scan, the "first scan" bit is set to 0.)
● You can assign one byte in M memory for clock memory. Each bit of the byte configured
as clock memory generates a square wave pulse. The byte of clock memory provides 8
different frequencies, from 0.5 Hz (slow) to 10 Hz (fast). You can use these bits as control
bits, especially when combined with edge instructions, to trigger actions in the user
program on a cyclic basis.
The CPU initializes these bytes on the transition from STOP mode to STARTUP mode. The
bits of the clock memory change synchronously to the CPU clock throughout the STARTUP
and RUN modes.
CAUTION
Overwriting the system memory or clock memory bits can corrupt the data in these
functions and cause your user program to operate incorrectly, which can cause damage to
equipment and injury to personnel.
Because both the clock memory and system memory are unreserved in M memory,
instructions or communications can write to these locations and corrupt the data.
Avoid writing data to these locations to ensure the proper operation of these functions, and
always implement an emergency stop circuit for your process or machine.
System memory configures a byte that turns on (value = 1) for a specific event.

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● First cycle: Turns on for the first scan cycle in run mode
● Diagnostic graph changed
● Always 1 (high): Always turned on
● Always 0 (low): Always turned off
Table 4- 6
7

System memory
3

Reserved

Always off

Always on

First scan indicator

Value 0

Value 1

Diagnostic status
indicator


1: Change



0: No change



1: First scan after
startup



0: Not first scan

Clock memory configures a byte that cycles the individual bits on and off at fixed intervals.
Each clock bit generates a square wave pulse on the corresponding M memory bit. These
bits can be used as control bits, especially when combined with edge instructions, to trigger
actions in the user code on a cyclic basis.

Table 4- 7

Clock memory

Bit number

Period (s)

2.0

1.6

1.0

0.8

0.5

Frequency (Hz)

0.5

0.625

1.25

0.4

0.2

0.1

2.5

Because clock memory runs asynchronously to the CPU cycle, the status of the clock memory can change several times
during a long cycle.

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4.1.6.2

Configuring the outputs on a RUN-to-STOP transition
You can configure the behavior of the digital and analog outputs when the CPU is in STOP
mode. For any output of a CPU, SB or SM, you can set the outputs to either freeze the value
or use a substitute value:
● Substituting a specified output value (default): You enter a substitute value for each
output (channel) of that CPU, SB, or SM device.
The default substitute value for digital output channels is OFF, and the default substitute
value for analog output channels is 0.
● Freezing the outputs to remain in last state: The outputs retain their current value at the
time of the transition from RUN to STOP. After power up, the outputs are set to the
default substitute value.
You configure the behavior of the outputs in Device Configuration. Select the individual
devices and use the "Properties" tab to configure the outputs for each device.
When the CPU changes from RUN to STOP, the CPU retains the process image and writes
the appropriate values for both the digital and analog outputs, based upon the configuration.

4.2

Data storage, memory areas, I/O and addressing

4.2.1

Accessing the data of the S7-1200
STEP 7 facilitates symbolic programming. You create symbolic names or "tags" for the
addresses of the data, whether as PLC tags relating to memory addresses and I/O points or
as local variables used within a code block. To use these tags in your user program, simply
enter the tag name for the instruction parameter.
For a better understanding of how the CPU structures and addresses the memory areas, the
following paragraphs explain the "absolute" addressing that is referenced by the PLC tags.
The CPU provides several options for storing data during the execution of the user program:
● Global memory: The CPU provides a variety of specialized memory areas, including
inputs (I), outputs (Q) and bit memory (M). This memory is accessible by all code blocks
without restriction
● Data block (DB): You can include DBs in your user program to store data for the code
blocks. The data stored persists when the execution of the associated code block comes
to an end. A "global" DB stores data that can be used by all code blocks, while an
instance DB stores data for a specific FB and is structured by the parameters for the FB.
● Temp memory: Whenever a code block is called, the operating system of the CPU
allocates the temporary, or local, memory (L) to be used during the execution of the
block. When the execution of the code block finishes, the CPU reallocates the local
memory for the execution of other code blocks.

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Each different memory location has a unique address. Your user program uses these
addresses to access the information in the memory location. References to the input (I) or
output (Q) memory areas, such as I0.3 or Q1.7, access the process image. To immediately
access the physical input or output, append the reference with ":P" (such as I0.3:P, Q1.7:P,
or "Stop:P").
Table 4- 8

Memory areas

Memory area

Description

Force

Retentive

I
Process image input

Copied from physical inputs at the beginning of the scan
cycle

I_:P 1
(Physical input)

Immediate read of the physical input points on the CPU,
SB, and SM

Yes

Q
Process image output

Copied to physical outputs at the beginning of the scan
cycle

Q_:P 1
(Physical output)

Immediate write to the physical output points on the
CPU, SB, and SM

Yes

M
Bit memory

Control and data memory

Yes
(optional)

L
Temp memory

Temporary data for a block local to that block

DB
Data block

Data memory and also parameter memory for FBs

Yes
(optional)

To immediately access (read or write) the physical inputs and physical outputs, append a ":P" to the address or tag
(such as I0.3:P, Q1.7:P, or "Stop:P").

Each different memory location has a unique address. Your user program uses these
addresses to access the information in the memory location. The absolute address consists
of the following elements:
● Memory area identifier (such as I, Q, or M)
● Size of the data to be accessed ("B' for Byte, "W" for Word, or "D" for DWord)
● Starting address of the data (such as byte 3 or word 3)
When accessing a bit in the address for a Boolean value, you do not enter a mnemonic for
the size. You enter only the memory area, the byte location, and the bit location for the data
(such as I0.0, Q0.1, or M3.4).

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0
࿆ ࿇ ࿈࿉

࿊

࿋
A

Memory area identifier

Bytes of the memory area

Byte address: byte 3

Bits of the selected byte

Separator ("byte.bit")

Bit location of the byte (bit 4 of 8)

In the example, the memory area and byte address (M = bit memory area, and 3 = Byte 3)
are followed by a period (".") to separate the bit address (bit 4).

Accessing the data in the memory areas of the CPU
STEP 7 facilitates symbolic programming. Typically, tags are created either in PLC tags, a
data block, or in the interface at the top of an OB, FC, or FB. These tags include a name,
data type, offset, and comment. Additionally, in a data block, a start value can be specified.
You can use these tags when programming by entering the tag name at the instruction
parameter. Optionally you can enter the absolute operand (memory area, size and offset) at
the instruction parameter. The examples in the following sections show how to enter
absolute operands. The % character is inserted automatically in front of the absolute
operand by the program editor. You can toggle the view in the program editor to one of
these: symbolic, symbolic and absolute, or absolute.
I (process image input): The CPU samples the peripheral (physical) input points just prior to
the cyclic OB execution of each scan cycle and writes these values to the input process
image. You can access the input process image as bits, bytes, words, or double words. Both
read and write access is permitted, but typically, process image inputs are only read.
Table 4- 9

Absolute addressing for I memory

Bit

I[byte address].[bit address]

I0.1

Byte, Word, or Double Word

I[size][starting byte address]

IB4, IW5, or ID12

By appending a ":P" to the address, you can immediately read the digital and analog inputs
of the CPU, SB or SM. The difference between an access using I_:P instead of I is that the
data comes directly from the points being accessed rather than from the input process
image. This I_:P access is referred to as an "immediate read" access because the data is
retrieved immediately from the source instead of from a copy that was made the last time the
input process image was updated.
Because the physical input points receive their values directly from the field devices
connected to these points, writing to these points is prohibited. That is, I_:P accesses are
read-only, as opposed to I accesses which can be read or write.

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I_:P accesses are also restricted to the size of inputs supported by a single CPU, SB, or SM,
rounded up to the nearest byte. For example, if the inputs of a 2 DI / 2 DQ SB are configured
to start at I4.0, then the input points can be accessed as I4.0:P and I4.1:P or as IB4:P.
Accesses to I4.2:P through I4.7:P are not rejected, but make no sense since these points are
not used. Accesses to IW4:P and ID4:P are prohibited since they exceed the byte offset
associated with the SB.
Accesses using I_:P do not affect the corresponding value stored in the input process image.
Table 4- 10

Absolute addressing for I memory (immediate)

Bit

I[byte address].[bit address]:P

I0.1:P

Byte, Word, or Double word

I[size][starting byte address]:P

IB4:P, IW5:P, or ID12:P

Q (process image output): The CPU copies the values stored in the output process image to
the physical output points. You can access the output process image in bits, bytes, words, or
double words. Both read and write access is permitted for process image outputs.
Table 4- 11

Absolute addressing for Q memory

Bit

Q[byte address].[bit address]

Q1.1

Byte, Word, or Double word

Q[size][starting byte address]

QB5, QW10, QD40

By appending a ":P" to the address, you can immediately write to the physical digital and
analog outputs of the CPU, SB or SM. The difference between an access using Q_:P instead
of Q is that the data goes directly to the points being accessed in addition to the output
process image (writes to both places). This Q_:P access is sometimes referred to as an
"immediate write" access because the data is sent immediately to the target point; the target
point does not have to wait for the next update from the output process image.
Because the physical output points directly control field devices that are connected to these
points, reading from these points is prohibited. That is, Q_:P accesses are write-only, as
opposed to Q accesses which can be read or write.
Q_:P accesses are also restricted to the size of outputs supported by a single CPU, SB, or
SM, rounded up to the nearest byte. For example, if the outputs of a 2 DI / 2 DQ SB are
configured to start at Q4.0, then the output points can be accessed as Q4.0:P and Q4.1:P or
as QB4:P. Accesses to Q4.2:P through Q4.7:P are not rejected, but make no sense since
these points are not used. Accesses to QW4:P and QD4:P are prohibited since they exceed
the byte offset associated with the SB.
Accesses using Q_:P affect both the physical output as well as the corresponding value
stored in the output process image.
Table 4- 12

Absolute addressing for Q memory (immediate)

Bit

Q[byte address].[bit address]:P

Q1.1:P

Byte, Word, or Double word

Q[size][starting byte address]:P

QB5:P, QW10:P or QD40:P

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M (bit memory area): Use the bit memory area (M memory) for both control relays and data
to store the intermediate status of an operation or other control information. You can access
the bit memory area in bits, bytes, words, or double words. Both read and write access is
permitted for M memory.
Table 4- 13

Absolute addressing for M memory

Bit

M[byte address].[bit address]

M26.7

Byte, Word, or Double Word

M[size][starting byte address]

MB20, MW30, MD50

Temp (temporary memory): The CPU allocates the temp memory on an as-needed basis.
The CPU allocates the temp memory for the code block at the time when the code block is
started (for an OB) or is called (for an FC or FB). The allocation of temp memory for a code
block might reuse the same temp memory locations previously used by a different OB, FC or
FB. The CPU does not initialize the temp memory at the time of allocation and therefore the
temp memory might contain any value.
Temp memory is similar to M memory with one major exception: M memory has a "global"
scope, and temp memory has a "local" scope:
● M memory: Any OB, FC, or FB can access the data in M memory, meaning that the data
is available globally for all of the elements of the user program.
● Temp memory: Access to the data in temp memory is restricted to the OB, FC, or FB that
created or declared the temp memory location. Temp memory locations remain local and
are not shared by different code blocks, even when the code block calls another code
block. For example: When an OB calls an FC, the FC cannot access the temp memory of
the OB that called it.
The CPU provides temp (local) memory for each of the three OB priority groups:
● 16 Kbytes for startup and program cycle, including associated FBs and FCs
● 4 Kbytes for standard interrupt events including FBs and FCs
● 4 Kbytes for error interrupt events including FBs and FCs
You access temp memory by symbolic addressing only.
DB (data block): Use the DB memory for storing various types of data, including intermediate
status of an operation or other control information parameters for FBs, and data structures
required for many instructions such as timers and counters. You can specify a data block to
be either read/write or read only. You can access data block memory in bits, bytes, words, or
double words. Both read and write access is permitted for read/write data blocks. Only read
access is permitted for read-only data blocks.
Table 4- 14

Absolute addressing for DB memory

Bit

DB[data block number].DBX[byte
address].[bit address]

DB1.DBX2.3

Byte, Word, or Double
Word

DB[data block number].DB [size][starting
byte address]

DB1.DBB4, DB10.DBW2,
DB20.DBD8

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Configuring the I/O in the CPU and I/O modules
When you add a CPU and I/O modules to your
configuration screen, I and Q addresses are
automatically assigned. You can change the
default addressing by selecting the address field in
the configuration screen and typing new numbers.
 Digital inputs and outputs are assigned in
groups of 8 points (1 byte), whether the module
uses all the points or not.
 Analog inputs and outputs are assigned in
groups of 2 points (4 bytes).

The figure shows an example of a CPU 1214C with two SMs and one SB. In this example,
you could change the address of the DI8 module to 2 instead of 8. The tool will assist you by
changing address ranges that are the wrong size or conflict with other addresses.

4.3

Processing of analog values
Analog signal modules provide input signals or expect output values that represent either a
voltage range or a current range. These ranges are ±10V, ±5V, ±2.5V, or 0 - 20mA. The
values returned by the modules are integer values where 0 to 27648 represents the rated
range for current, and -27648 to 27648 for voltage. Anything outside the range represents
either an overflow or underflow. See the tables for analog input representation (Page 607)
and analog output representation (Page 607) for details.
In your control program, you probably need to use these values in engineering units, for
example to represent a volume, temperature, weight or other quantitative value. To do this
for an analog input, you must first normalize the analog value to a real (floating point) value
from 0.0 to 1.0. Then you must scale it to the minimum and maximum values of the
engineering units that it represents. For values that are in engineering units that you need to
convert to an analog output value, you first normalize the value in engineering units to a
value between 0.0 and 1.0, and then scale it between 0 and 27648 or -27648 to 27648,
depending on the range of the analog module. STEP 7 provides the NORM_X and SCALE_X
instructions (Page 186) for this purpose. You can also use the CALCULATE instruction
(Page 169) to scale the analog values (Page 30).

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4.4 Data types

4.4

Data types
Data types are used to specify both the size of a data element as well as how the data are to
be interpreted. Each instruction parameter supports at least one data type, and some
parameters support multiple data types. Hold the cursor over the parameter field of an
instruction to see which data types are supported for a given parameter.
A formal parameter is the identifier on an instruction that marks the location of data to be
used by that instruction (example: the IN1 input of an ADD instruction). An actual parameter
is the memory location or constant containing the data to be used by the instruction
(example %MD400 "Number_of_Widgets"). The data type of the actual parameter specified
by you must match one of the supported data types of the formal parameter specified by the
instruction.
When specifying an actual parameter, you must specify either a tag (symbol) or an absolute
(direct) memory address. Tags associate a symbolic name (tag name) with a data type,
memory area, memory offset, and comment, and can be created either in the PLC tags
editor or in the Interface editor for a block (OB, FC, FB and DB). If you enter an absolute
address that has no associated tag, you must use an appropriate size that matches a
supported data type, and a default tag will be created upon entry.
All data types except String are available in the PLC tags editor and the block Interface
editors. String is available only in the block Interface editors. You can also enter a constant
value for many of the input parameters.
● Bit and Bit sequences (Page 85): Bool (Boolean or bit value), Byte (8-bit byte value),
Word (16-bit value), DWord (32-bit double-word value)
● Integer (Page 86)
– USInt (unsigned 8-bit integer), SInt (signed 8-bit integer),
– UInt (unsigned 16-bit integer), Int (signed 16-bit integer)
– UDInt (unsigned 32-bit integer), DInt (signed 32-bit integer)
● Floating-point Real (Page 86): Real (32-bit Real or floating-point value), LReal (64-bit
Real or floating-point value)
● Time and Date (Page 87): Time (32-bit IEC time value), Date (16-bit date value), TOD
(32-bit time-off-day value), DT (64-bit date-and-time value)
● Character and String (Page 87): Char (8-bit single character), String (variable-length
string of up to 254 characters)
● Array (Page 87)
● Data structure (Page 91): Struct
● PLC Data type (Page 91)
● Pointers (Page 92): Pointer, Any, Variant
Although not available as data types, the following BCD numeric format is supported by the
conversion instructions.

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4.4 Data types
Table 4- 15
Format

4.4.1

Size and range of the BCD format
Size (bits)

Numeric Range

Constant Entry Examples

BCD16

-999 to 999

123, -123

BCD32

-9999999 to 9999999

1234567, -1234567

Bool, Byte, Word, and DWord data types

Table 4- 16

Bit and bit sequence data types

Data
type

Bit
size

Number
type

Number
range

Constant
examples

Address
examples

Bool

Boolean

FALSE or TRUE

TRUE, 1,

I1.0
Q0.1
M50.7
DB1.DBX2.3
Tag_name

Byte

Word

Binary

0 or 1

0, 2#0

Octal

8#0 or 8#1

8#1

Hexadecimal

16#0 or 16#1

16#1

Binary

2#0 to 2#11111111

2#00001111

Unsigned integer

0 to 255

Octal

8#0 to 8#377

8#17

Hexadecimal

B#16#0 to B#16#FF

B#16#F, 16#F

Binary

2#0 to 2#1111111111111111

2#1111000011110000

Unsigned integer

0 to 65535

61680

Octal

8#0 to 8#177777

8#170360

W#16#0 to W#16#FFFF,

W#16#F0F0, 16#F0F0

Hexadecimal

IB2
MB10
DB1.DBB4
Tag_name
MW10
DB1.DBW2
Tag_name

16#0 to 16#FFFF
DWord

Binary

2#0 to
2#111111111111111111111111
11111111

2#111100001111111100
001111

Unsigned integer

0 to 4294967295

15793935

Octal

8#0 to 8#37777777777

8#74177417

Hexadecimal

DW#16#0000_0000 to
DW#16#FFFF_FFFF,

DW#16#F0FF0F,
16#F0FF0F

MD10
DB1.DBD8
Tag_name

16#0000_0000 to
16#FFFF_FFFF

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4.4 Data types

4.4.2
Table 4- 17

Integer data types
Integer data types (U = unsigned, S = short, D= double)

Data type

Bit size

Number Range

Constant examples

Address
examples

USInt

0 to 255

78, 2#01001110

SInt

-128 to 127

+50, 16#50

UInt

0 to 65,535

65295, 0

Int

-32,768 to 32,767

30000, +30000

UDInt

0 to 4,294,967,295

4042322160

DInt

-2,147,483,648 to
2,147,483,647

-2131754992

4.4.3

MB0, DB1.DBB4,
Tag_name
MW2, DB1.DBW2,
Tag_name
MD6, DB1.DBD8,
Tag_name

Floating-point real data types
Real (or floating-point) numbers are represented as 32-bit single-precision numbers (Real),
or 64-bit double-precision numbers (LReal) as described in the ANSI/IEEE 754-1985
standard. Single-precision floating-point numbers are accurate up to 6 significant digits and
double-precision floating point numbers are accurate up to 15 significant digits. You can
specify a maximum of 6 significant digits (Real) or 15 (LReal) when entering a floating-point
constant to maintain precision.

Table 4- 18

Floating-point real data types (L=Long)

Data type Bit size Number range

Constant Examples

Address examples

Real

-3.402823e+38 to -1.175 495e-38,
±0,
+1.175 495e-38 to +3.402823e+38

123.456, -3.4, 1.0e-5

MD100, DB1.DBD8,
Tag_name

LReal

-1.7976931348623158e+308 to
-2.2250738585072014e-308,
±0,
+2.2250738585072014e-308 to
+1.7976931348623158e+308

12345.123456789e40,
1.2E+40

DB_name.var_name
Rules:


No direct addressing
support



Can be assigned in an
OB, FB, or FC block
interface table



Can be assigned in a
global or instance data
block , only when the data
block is created as the
"optimized" type (symbolic
access only)

Calculations that involve a long series of values including very large and very small numbers
can produce inaccurate results. This can occur if the numbers differ by 10 to the power of x,
where x > 6 (Real), or 15 (LReal). For example (Real): 100 000 000 + 1 = 100 000 000.

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4.4.4
Table 4- 19

Time and Date data types
Time and date data types

Data type

Size

Range

Constant Entry Examples

Time

32 bits

T#-24d_20h_31m_23s_648ms to
T#24d_20h_31m_23s_647ms

T#5m_30s
T#1d_2h_15m_30s_45ms
TIME#10d20h30m20s630ms
500h10000ms
10d20h30m20s630ms

Stored as: -2,147,483,648 ms to +2,147,483,647
ms
Date

16 bits

D#1990-1-1 to D#2168-12-31

D#2009-12-31
DATE#2009-12-31
2009-12-31

Time_of_Day

32 bits

TOD#0:0:0.0 to TOD#23:59:59.999

TOD#10:20:30.400
TIME_OF_DAY#10:20:30.400
23:10:1

DTL
(Date and Time
Long)

12 bytes

Min.: DTL#1970-01-01-00:00:00.0

DTL#2008-12-16-20:30:20.250

Max.: DTL#2554-12-31-23:59:59.999 999 999

Time
TIME data is stored as a signed double integer interpreted as milliseconds. The editor format
can use information for day (d), hours (h), minutes (m), seconds (s) and milliseconds (ms).
It is not necessary to specify all units of time. For example T#5h10s and 500h are valid.
The combined value of all specified unit values cannot exceed the upper or lower limits in
milliseconds for the Time data type (-2,147,483,648 ms to +2,147,483,647 ms).

Date
DATE data is stored as an unsigned integer value which is interpreted as the number of days
added to the base date 01/01/1990, to obtain the specified date. The editor format must
specify a year, month and day.

TOD
TOD (TIME_OF_DAY) data is stored as an unsigned integer which is interpreted as the
number of milliseconds since midnight for the specified time of day (Midnight = 0 ms). The
hour (24hr/day), minute, and second must be specified. The fractional second specification is
optional.

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4.4 Data types

DTL
DTL (Date and Time Long) data type uses a12 byte structure that saves information on date
and time. You can define DTL data in either the Temp memory of a block or in a DB. A value
for all components must be entered in the "Start value" column of the DB editor.
Table 4- 20
Length
(bytes)
12

Size and range for DTL
Format

Value range

Example of value input

Clock and calendar

Min.: DTL#1970-01-01-00:00:00.0

DTL#2008-12-16-20:30:20.250

Year-Month-Day:Hour:Minute:
Second.Nanoseconds

Max.: DTL#2554-12-31-23:59:59.999
999 999

Each component of the DTL contains a different data type and range of values. The data
type of a specified value must match the data type of the corresponding components.
Table 4- 21

Elements of the DTL structure

Byte

Component

Data type

Value range

Year

UINT

1970 to 2554

Month

USINT

1 to 12

Day

USINT

1 to 31

Weekday

USINT

1(Sunday) to 7(Saturday) 1

Hour

USINT

0 to 23

Minute

USINT

0 to 59

Second

USINT

0 to 59

Nanoseconds

UDINT

0 to 999 999 999

9
10
11
The weekday is not considered in the value entry.

Table 4- 22

Character and String data types

Data type

Size

Range

Constant Entry Examples

Char

8 bits

ASCII character codes: 16#00 to 16#FF

'A', 't', '@'

String

n+ 2 bytes

n = (0 to 254 character bytes)

'ABC'

Char
Char data occupies one byte in memory and stores a single character coded in ASCII
format. The editor syntax uses a single quote character before and after the ASCII character.
Visible characters and control characters can be used. A table of valid control characters is
shown in the description of the String data type.

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String
The CPU supports the String data type for storing a sequence of single-byte characters. The
String data type contains a total character count (number of characters in the string) and the
current character count. The String type provides up to 256 bytes for storing the maximum
total character count (1 byte), the current character count (1 byte), and up to 254 characters,
with each character stored in 1 byte.
You can use literal strings (constants) for instruction parameters of type IN using single
quotes. For example, ‘ABC’ is a three-character string that could be used as input for
parameter IN of the S_CONV instruction. You can also create string variables by selecting
data type "String" in the block interface editors for OB, FC, FB, and DB. You cannot create a
string in the PLC tags editor.
You can specify the maximum string size in bytes by entering square brackets after the
keyword "String" (once the data type "String" is selected from a data type drop-list). For
example, "MyString[10]" would specify a 10-byte maximum size for MyString. If you do not
include the square brackets with a maximum size, then 254 is assumed.
The following example defines a String with maximum character count of 10 and current
character count of 3. This means the String currently contains 3 one-byte characters, but
could be expanded to contain up to 10 one-byte characters.
Table 4- 23

Example of a String data type

Total Character
Count

Current Character
Count

Character 1

Character 2

Character 3

...

Character 10

'C' (16#43)

'A' (16#41)

'T' (16#54)

...

Byte 0

Byte 1

Byte 2

Byte 3

Byte 4

...

Byte 11

ASCII control characters can be used in Char and String data. The following table shows
examples of control character syntax.
Table 4- 24

Valid ASCII control characters

Control characters

ASCII Hex value

Control function

Examples

$L or $l

Line feed

'$LText', '$0AText'

$N or $n

0A and 0D

Line break

'$NText', '$0A$0DText'

The new line shows two characters in the
string.
$P or $p

Form feed

'$PText', '$0CText'

$R or $r

Carriage return (CR)

'$RText','$0DText'

$T or $t

Tab

'$TText', '$09Text'

Dollar sign

'100$$', '100$24'

Single quote

'$'Text$'','$27Text$27'

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4.4 Data types

Arrays
You can create an array that contains multiple elements of the same data type. Arrays can
be created in the block interface editors for OB, FC, FB, and DB. You cannot create an array
in the PLC tags editor.
To create an array from the block interface editor, name the array and choose data type
"Array [lo .. hi] of type", then edit "lo", "hi", and "type" as follows:
● lo - the starting (lowest) index for your array
● hi - the ending (highest) index for your array
● type - one of the data types, such as BOOL, SINT, UDINT
Table 4- 25

ARRAY data type rules

Data Type

Array syntax

ARRAY

Name [index1_min..index1_max, index2_min..index2_max] of


All array elements must be the same data type.



The index can be negative, but the lower limit must be less than or equal to the upper limit.



Arrays can have one to six dimensions.



Multi-dimensional index min..max declarations are separated by comma characters.



Nested arrays, or arrays of arrays, are not allowed.



The memory size of an array = (size of one element * total number of elements in array)

Array index

Valid index data types

Array index rules

Constant or
variable

USInt, SInt, UInt, Int, UDInt,
DInt



Value limits: -32768 to +32767



Valid: Mixed constants and variables



Valid: Constant expressions



Not valid: Variable expressions

Example: array
declarations
Example: array
addresses

ARRAY[1..20] of REAL

One dimension, 20 elements

ARRAY[-5..5] of INT

One dimension, 11 elements

ARRAY[1..2, 3..4] of CHAR

Two dimensions, 4 elements

ARRAY1[0]

ARRAY1 element 0

ARRAY2[1,2]

ARRAY2 element [1,2]

ARRAY3[i,j]

If i =3 and j=4, then ARRAY3 element
[3, 4] is addressed

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4.4 Data types

4.4.5

Data structure data type
You can use the data type "Struct" to define a structure of data consisting of other data
types. The struct data type can be used to handle a group of related process data as a single
data unit. A Struct data type is named and the internal data structure declared in the data
block editor or a block interface editor.
Arrays and structures can also be assembled into a larger structure. A structure can be
nested up to eight levels deep. For example, you can create a structure of structures that
contain arrays.
A Struct variable begins at an even-byte address and uses the memory to the next word
boundary.

4.4.6

PLC data type
The PLC data type editor lets you define data structures that you can use multiple times in
your program. You create a PLC data type by opening the "PLC data types" branch of the
project tree and double-clicking the "Add new data type" item. On the newly created PLC
data type item, use two single-clicks to rename the default name and double-click to open
the PLC data type editor.
You create a custom PLC data type structure using the same editing methods that are used
in the data block editor. Add new rows for any data types that are necessary to create the
data structure that you want.
If a new PLC data type is created, then the new PLC type name will appear in the data type
selector drop drop-lists in the DB editor and code block interface editor.
Potential uses of PLC data types:
● PLC data types can be used directly as a data type in a code block interface or in data
blocks.
● PLC data types can be used as a template for the creation of multiple global data blocks
that use the same data structure.
For example, a PLC data type could be a recipe for mixing colors. You can then assign this
PLC data type to multiple data blocks. Each data block can then have the variables adjusted
to create a specific color.

4.4.7

Pointer data types
The pointer data types (Pointer, Any, and Variant) can be used in the block interface tables
for FB and FC code blocks. You can select a pointer data type from the block interface data
type drop-lists.
The Variant data type is also used for instruction parameters.

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4.4 Data types

4.4.7.1

"Pointer" pointer data type
The data type Pointer points to a particular variable. It occupies 6 bytes (48 bits) in memory
and can include the following information:
● DB number or 0 if the data is not stored in a DB
● Storage area in the CPU
● Variable address
3RLQWHUIRUPDW
%LW

%LW

%\WH

'%QXPEHU RU

%\WH
%\WH

0HPRU\DUHD
E

%\WH

[

%\WH

E E\WHDGGUHVV

[ ELWDGGUHVV

Depending on the instruction, you can declare the following three types of pointers:
● Area-internal pointer: contains data on the address of a variable
● Area-crossing pointer: contains data on the memory area and the address of a variable
● DB-pointer: contains a data block number and the address of a variable
Table 4- 26

Pointer types:

Type

Format

Example entry

Area-internal pointer

P#Byte.Bit

P#20.0

Area-crossing pointer

P#Memory_area_Byte.Bit

P#M20.0

DB-pointer

P#Data_block.Data_element

P#DB10.DBX20.0

You can enter a parameter of type Pointer without the prefix (P #). Your entry will be
automatically converted to the pointer format.
Table 4- 27

Memory area encoding in the Pointer data:

Hexadecimal code

Data type

Description

b#16#81

Input memory area

b#16#82

Output memory area

b#16#83

Marker memory area

b#16#84

DBX

Data block

b#16#85

DIX

Instance data block

b#16#86

Local data

b#16#87

Previous local data

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4.4 Data types

4.4.7.2

"Any" pointer data type
The pointer data type ANY ("Any") points to the beginning of a data area and specifies its
length. The ANY pointer uses 10 bytes in memory and can include the following information:
● Data type: Data type of the data elements
● Repeat factor: Number of data elements
● DB Number: Data block in which data elements are stored
● Storage area: Memory area of the CPU, in which the data elements are stored
● Start address: "Byte.Bit" starting address of the data
The following image shows the structure of the ANY pointer:
%LW

%LW

%\WH

KIRU6

%\WH

'DWDW\SH

%\WH

5HSHDWIDFWRU

%\WH

'%1XPEHU RU

%\WH
%\WH

0HPRU\DUHD
E

%\WH

[

%\WH

E %\WHDGUHVV

[ %LWDGUHVV

A pointer can not detect ANY structures. It can only be assigned to local variables.
Table 4- 28

Format and examples of the ANY pointer:

Format

Entry example

Description

P#Data_block.Memory_area
Data_address Type Number

P#DB 11.DBX 20.0 INT 10

10 words in global DB 11
starting from DBB 20.0

P#Memory_area Data_address
Type Number

P#M 20.0 BYTE 10

10 bytes starting from MB 20.0

P#I 1.0 BOOL 1

Input I1.0

Table 4- 29

Data type encoding in the ANY pointer

Hexadecimal code

Data type

Description

b#16#00

Null

Null pointer

b#16#01

Bool

Bits

b#16#02

Byte

Bytes, 8 Bits

b#16#03

Char

8-bit character

b#16#04

Word

16-bit-word

b#16#05

Int

16-bit-integer

b#16#37

SInt

8-bit-integer

b#16#35

UInt

16-bit unsigned integer

b#16#34

USInt

8-bit unsigned integer

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4.4 Data types

Hexadecimal code

Data type

Description

b#16#06

DWord

32-bit double word

b#16#07

DInt

32-bit double integer

b#16#36

UDInt

32-bit-unsigned double integer

b#16#08

Real

32-Bit floating point

b#16#0B

Time

b#16#13

String

Character string

Table 4- 30

4.4.7.3

Memory area encoding in the ANY pointer:

Hexadecimal code

Memory area

Description

b#16#81

Input memory area

b#16#82

Output memory area

b#16#83

Marker memory area

b#16#84

DBX

Data block

b#16#85

DIX

Instance data block

b#16#86

Local data

b#16#87

Previous local data

"Variant" pointer data type
The data type Variant is can point to variables of different data types or parameters. The
Variant pointer can point to structures and individual structural components. The Variant
pointer does not occupy any space in memory.

Table 4- 31

Properties of the Variant pointer

Length
(Byte)

Representation

Format

Example entry

Symbolic

Operand

MyTag

DB_name.Struct_name.element_name

MyDB.Struct1.pressure1

Operand

%MW10

DB_number.Operand Type Length

P#DB10.DBX10.0 INT 12

Absolute

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4.5 Using a memory card

4.5

Using a memory card
NOTICE
The CPU supports only the pre-formatted SIMATIC memory card (Page 651).
Before you copy any program to the formatted memory card, delete any previously saved
program from the memory card.
Use the memory card either as a transfer card or as a program card. Any program that you
copy to the memory card contains all of the code blocks and data blocks, any technology
objects, and the device configuration. The program does not contain force values.
● Use a transfer card to copy a program to the internal load memory of the CPU without
using STEP 7. After you insert the transfer card, the CPU first erases the user program
and any force values from the internal load memory, and then copies the program from
the transfer card to the internal load memory. When the transfer process is complete, you
must remove the transfer card.
You can use an empty transfer card to access a password-protected CPU when the
password has been lost or forgotten (Page 102). Inserting the empty transfer card deletes
the password-protected program in the internal load memory of the CPU. You can then
download a new program to the CPU.
● Use a program card as external load memory for the CPU. Inserting a program card in
the CPU erases all of the CPU internal load memory (the user program and any force
values). The CPU then executes the program in external load memory (the program
card). Downloading to a CPU that has a program card updates only the external load
memory (the program card).
Because the internal load memory of the CPU was erased when you inserted the
program card, the program card must remain in the CPU. If you remove the program
card, the CPU goes to STOP mode. (The error LED flashes to indicate that program card
has been removed.)
The program on a memory card includes the code blocks, the data blocks, the technology
objects, and the device configuration. The memory card does not contain any force values.
The force values are not part of the program, but are stored in the load memory, whether the
internal load memory of the CPU, or the external load memory (a program card). If a
program card is inserted in the CPU, then STEP 7 applies the force values only to the
external load memory on the program card.
You also use a memory card when downloading firmware updates from customer support
(http://www.siemens.com/automation/support-request). A firmware update requires a 24 MB
memory card.

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4.5 Using a memory card

4.5.1

Inserting a memory card in the CPU
CAUTION
Electrostatic discharge can damage the memory card or the receptacle on the CPU.
Make contact with a grounded conductive pad and/or wear a grounded wrist strap when
you handle the memory card. Store the memory card in a conductive container.

Check that the memory card is not write-protected. Slide the protection
switch away from the "Lock" position.

CAUTION
If you insert a memory card (whether configured as a program or transfer card) into a
running CPU, the CPU goes immediately to STOP mode, which might result damage to the
equipment or to the process being controlled. Before inserting or removing a memory card,
always ensure that the CPU is not actively controlling a machine or process. Always install
an emergency stop circuit for your application or process.
Note
If you insert a memory card with the CPU in STOP mode, the diagnostic buffer displays a
message that the memory card evaluation has been initiated. The CPU will evaluate the
memory card the next time you either change the CPU to RUN mode, reset the CPU
memory with an MRES, or power-cycle the CPU.

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To insert a memory card, open the top
CPU door and insert the memory card in
the slot. A push-push type connector
allows for easy insertion and removal.
The memory card is keyed for proper
installation.

4.5.2

Configuring the startup parameter of the CPU before copying the project to the
memory card
When you copy a program to a transfer card or a program card, the program includes the
startup parameter for the CPU. Before copying the program to the memory card, always
ensure that you have configured the operating mode for the CPU following a power-cycle.
Select whether the CPU starts in STOP mode, RUN mode, or in the previous mode (prior to
the power cycle).

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4.5 Using a memory card

4.5.3

Transfer card
CAUTION
Electrostatic discharge can damage the memory card or the receptacle on the CPU.
Make contact with a grounded conductive pad and/or wear a grounded wrist strap
whenever you handle the memory card. Store the memory card in a conductive container.

Creating a transfer card
Always remember to configure the startup parameter of the CPU (Page 97) before copying a
program to the transfer card. To create a transfer card, follow these steps:
1. Insert a blank SIMATIC memory card into an SD card reader/writer attached to your
computer.
If you are reusing a SIMATIC memory card that contains a user program or another
firmware update, you must delete the program files before downloading the firmware
update. Use Windows Explorer to display the contents of the memory card and delete the
"S7_JOB.S7S" file and also delete any directory folder (such as "SIMATIC.S7S" or
"FWUPDATE.S7S").
2. In the Project tree (Project view), expand the "SIMATIC Card Reader" folder and select
your card reader.
3. Display the "Memory card" dialog by right-clicking the memory card in the card reader
and selecting "Properties" from the context menu.
4. In the "Memory card" dialog, select "Transfer" from the drop-down menu.
At this point, STEP 7 creates the empty transfer card. If you are creating an empty
transfer card, such as to recover from a lost CPU password (Page 102), remove the
transfer card from the card reader.

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4.5 Using a memory card
5. Add the program by selecting the CPU device (such as PLC_1 [CPU 1214 DC/DC/DC]) in
the Project tree and dragging the CPU device to the memory card. (Another method is to
copy the CPU device and paste it to the memory card.) Copying the CPU device to the
memory card opens the "Load preview" dialog.
6. In the "Load preview" dialog, click the "Load" button to copy the CPU device to the
memory card.
7. When the dialog displays a message that the CPU device (program) has been loaded
without errors, click the "Finish" button.

Using a transfer card
WARNING
Verify that the CPU is not actively running a process before inserting the memory card.
Inserting a memory card will cause the CPU to go to STOP mode, which could affect the
operation of an online process or machine. Unexpected operation of a process or machine
could result in death or injury to personnel and/or property damage.
Before inserting a memory card, always ensure that the CPU is offline and in a safe state.
To transfer the program to a CPU, follow these steps:
1. Insert the transfer card into the CPU (Page 96). If the CPU is in RUN, the CPU will go to
STOP mode. The maintenance (MAINT) LED flashes to indicate that the memory card
needs to be evaluated.
2. Power-cycle the CPU to evaluate the memory card. Alternative methods for rebooting the
CPU are to perform either a STOP-to-RUN transition or a memory reset (MRES) from
STEP 7.
3. After the rebooting and evaluating the memory card, the CPU copies the program to the
internal load memory of the CPU.
The RUN/STOP LED alternately flashes green and yellow to indicate that the program is
being copied. When the RUN/STOP LED turns on (solid yellow) and the MAINT LED
flashes, the copy process has finished. You can then remove the memory card.
4. Reboot the CPU (either by restoring power or by the alternative methods for rebooting) to
evaluate the new program that was transferred to internal load memory.
The CPU then goes to the start-up mode (RUN or STOP) that you configured for the project.
Note
You must remove the transfer card before setting the CPU to RUN mode.

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4.5 Using a memory card

4.5.4

Program card
CAUTION
Electrostatic discharge can damage the memory card or the receptacle on the CPU.
Make contact with a grounded conductive pad and/or wear a grounded wrist strap when
you handle the memory card. Store the memory card in a conductive container.

Check that the memory card is not write-protected. Slide the protection
switch away from the "Lock" position.
Before you copy any program elements to the program card, delete any
previously saved programs from the memory card.

Creating a program card
When used as a program card, the memory card is the external load memory of the CPU. If
you remove the program card, the internal load memory of the CPU is empty.
Note
If you insert a blank memory card into the CPU and perform a memory card evaluation by
either power cycling the CPU, performing a STOP to RUN transition, or performing a
memory reset (MRES), the program and force values in internal load memory of the CPU are
copied to the memory card. (The memory card is now a program card.) After the copy has
been completed, the program in internal load memory of the CPU is then erased. The CPU
then goes to the configured startup mode (RUN or STOP).
Always remember to configure the startup parameter of the CPU (Page 97) before copying a
project to the program card. To create a program card, follow these steps:
1. Insert a blank SIMATIC memory card into an SD card reader/writer attached to your
computer.
If you are reusing a SIMATIC memory card that contains a user program or another
firmware update, you must delete the program files before downloading the firmware
update. Use Windows Explorer to display the contents of the memory card and delete the
"S7_JOB.S7S" file and also delete any directory folder (such as "SIMATIC.S7S" or
"FWUPDATE.S7S").
2. In the Project tree (Project view), expand the "SIMATIC Card Reader" folder and select
your card reader.
3. Display the "Memory card" dialog by right-clicking the memory card in the card reader
and selecting "Properties" from the context menu.
4. In the "Memory card" dialog, select "Program" from the drop-down menu.
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4.5 Using a memory card

5. Add the program by selecting the CPU device (such as PLC_1 [CPU 1214 DC/DC/DC]) in
the Project tree and dragging the CPU device to the memory card. (Another method is to
copy the CPU device and paste it to the memory card.) Copying the CPU device to the
memory card opens the "Load preview" dialog.
6. In the "Load preview" dialog, click the "Load" button to copy the CPU device to the
memory card.
7. When the dialog displays a message that the CPU device (program) has been loaded
without errors, click the "Finish" button.

Using a program card as the load memory for your CPU
WARNING
Verify that the CPU is not actively running a process before inserting the memory card.
Inserting a memory card will cause the CPU to go to STOP mode, which could affect the
operation of an online process or machine. Unexpected operation of a process or machine
could result in death or injury to personnel and/or property damage.
Before inserting a memory card, always ensure that the CPU is offline and in a safe state.
To use a program card with your CPU, follow these steps:
1. Insert the program card into the CPU. If the CPU is in RUN mode, the CPU goes to STOP
mode. The maintenance (MAINT) LED flashes to indicate that the memory card needs to
be evaluated.
2. Power-cycle the CPU to evaluate the memory card. Alternative methods for rebooting the
CPU are to perform either a STOP-to-RUN transition or a memory reset (MRES) from
STEP 7.
3. After the CPU reboots and evaluates the program card, the CPU erases the internal load
memory of the CPU.

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PLC concepts
4.6 Recovery from a lost password
The CPU then goes to the start-up mode (RUN or STOP) that you configured for the CPU.
The program card must remain in the CPU. Removing the program card leaves the CPU with
no program in internal load memory.
WARNING
If you remove the program card, the CPU loses its external load memory and generates an
error. The CPU goes to STOP mode and flashes the error LED.
Control devices can fail in an unsafe condition, resulting in unexpected operation of
controlled equipment. Such unexpected operations could result in death or serious injury to
personnel, and/or damage to equipment.

4.6

Recovery from a lost password
If you have lost the password for a password-protected CPU, use an empty transfer card to
delete the password-protected program. The empty transfer card erases the internal load
memory of the CPU. You can then download a new user program from STEP 7 to the CPU.
For information about the creation and use of an empty transfer card, see the section of
transfer cards (Page 98).
WARNING
If you insert a transfer card in a running CPU, the CPU goes to STOP. Control devices can
fail in an unsafe condition, resulting in unexpected operation of controlled equipment. Such
unexpected operations could result in death or serious injury to personnel, and/or damage
to equipment.
You must remove the transfer card before setting the CPU to RUN mode.

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Device configuration

You create the device configuration for your PLC by adding a CPU and additional modules to
your project.

①
②
③
④
⑤

Communication module (CM) or communication processor (CP): Up to 3, inserted in slots 101,
102, and 103
CPU: Slot 1
Ethernet port of CPU
Signal board (SB) or communication board (CB): up to 1, inserted in the CPU
Signal module (SM) for digital or analog I/O: up to 8, inserted in slots 2 through 9
(CPU 1214C allows 8, CPU 1212C allows 2, CPU 1211C does not allow any)

To create the device configuration,
add a device to your project.
 In the Portal view, select
"Devices & Networks" and click
"Add new device".
 In the Project view, under the
project name, double-click "Add
new device".

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Device configuration
5.1 Inserting a CPU

5.1

Inserting a CPU
You create your device configuration by inserting a CPU into your project. Selecting the CPU
from the "Add new device" dialog creates the rack and CPU.
"Add new device" dialog

Device view of the hardware
configuration

Selecting the CPU in the Device
view displays the CPU
properties in the inspector
window.

Note
The CPU does not have a pre-configured IP address. You must manually assign an IP
address for the CPU during the device configuration. If your CPU is connected to a router on
the network, you also enter the IP address for a router.

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Device configuration
5.2 Detecting the configuration for an unspecified CPU

5.2

Detecting the configuration for an unspecified CPU
If you are connected to a CPU, you can upload the
configuration of that CPU, including any modules, to your
project. Simply create a new project and select the "unspecified
CPU" instead of selecting a specific CPU. (You can also skip
the device configuration entirely by selecting the "Create a PLC
program" from the "First steps". STEP 7 then automatically
creates an unspecified CPU.)
From the program editor, you select the "Hardware detection"
command from the "Online" menu.

From the device configuration editor, you select the option for detecting the configuration of
the connected device.

After you select the CPU from the online dialog and click the Load button, STEP 7 uploads
the hardware configuration from the CPU, including any modules (SM, SB, or CM). You can
then configure the parameters for the CPU and the modules.

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5.3 Adding modules to the configuration

5.3

Adding modules to the configuration
Use the hardware catalog to add modules to the CPU:
● Signal module (SM) provides additional digital or analog I/O points. These modules are
connected to the right side of the CPU.
● Signal board (SB) provides just a few additional I/O points for the CPU. The SB is
installed on the front of the CPU.
● Communication board (CB) provides an additional communication port (such as RS485).
The CB is installed on the front of the CPU.
● Communication module (CM) and communication processor (CP) provide an additional
communication port, such as for PROFIBUS or GPRS. These modules are connected to
the left side of the CPU.
To insert a module into the hardware configuration, select the module in the hardware
catalog and either double-click or drag the module to the highlighted slot.

Table 5- 1
Module

Adding a module to the device configuration
Select the module

Insert the module

Result

SB or CB

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Module

Select the module

Insert the module

Result

CM or CP

5.4

Configuring the operation of the CPU
To configure the operational parameters
for the CPU, select the CPU in the
Device view (blue outline around whole
CPU), and use the "Properties" tab of the
inspector window.

Table 5- 2

CPU properties

Property

Description

PROFINET interface

Sets the IP address for the CPU and time synchronization

DI, DO, and AI

Configures the behavior of the local (on-board) digital and analog I/O

High-speed counters
(Page 287) and pulse
generators (Page 262)

Enables and configures the high-speed counters (HSC) and the pulse generators used for
pulse-train operations (PTO) and pulse-width modulation (PWM)

Startup (Page 63)

When you configure the outputs of the CPU or signal board as pulse generators (for use with
the PWM or basic motion control instructions), the corresponding output addresses (Q0.0,
Q0.1, Q4.0, and Q4.1) are removed from the Q memory and cannot be used for other
purposes in your user program. If your user program writes a value to an output used as a
pulse generator, the CPU does not write that value to the physical output.
Startup mode: Selects the behavior of the CPU following an off-to-on transition, such as to
start in STOP mode or to go to RUN mode after a warm restart
Supported hardware compatibility: Configures whether modules (SM, SB, CM, CP or even
the CPU) can be substituted:


Allow acceptable substitute (default)

 Allow any substitute
For example, a 16-channel SM could be an acceptable substitute for an 8-channel I/O.

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Property

Description
I/O parameter assignment time for distributed I/O: Configures a maximum amount of time
(default: 60000 ms) for the distributed I/O to be brought online. (The CMs and CPs receive
power and communication parameters from the CPU during startup. This assignment time
allows time for the I/O connected to the CM or CP be brought online.)
The CPU goes to RUN as soon as the distributed I/O is online, regardless of the assignment
time. If the distributed I/O has not been brought online within this time, the CPU still goes to
RUN--without the distributed I/O.
Note: If your configuration uses a CM 1243-5 (PROFIBUS master), do not set this parameter
below 15 seconds (15000 ms) to ensure that the module to be brought online.

Cycle (Page 72)

Defines a maximum cycle time or a fixed minimum cycle time

Communication load

Allocates a percentage of the CPU time to be dedicated to communication tasks

System and clock memory
(Page 76)

Enables a byte for "system memory" functions and enables a byte for "clock memory"
functions (where each bit toggles on and off at a predefined frequency).

Web server (Page 491)

Enables and configures the Web server feature.

Time of day

Selects the time zone and configures daylight saving time

Protection (Page 138)

Sets the read/write protection and password for accessing the CPU

Connection resources
(Page 360)

Provides a summary of the communication connections that are available for the CPU and
the number of connections that have been configured.

Overview of addresses

Provides a summary of the I/O addresses that have been configured for the CPU.

5.5

Configuring the parameters of the modules
To configure the operational parameters for the modules, select the module in the Device
view and use the "Properties" tab of the inspector window to configure the parameters for the
module.

Configuring a signal module (SM) or a signal board (SB)

● Digital I/O: Inputs can be configured for rising-edge detection or falling-edge detection
(associating each with an event and hardware interrupt) and also for "pulse catch" (to
stay on after a momentary pulse) through the next update of the input process image.
Outputs can use a freeze or substitute value.

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● Analog I/O: For individual inputs, configure parameters, such as measurement type
(voltage or current), range and smoothing, and to enable underflow or overflow
diagnostics. Analog outputs provide parameters such as output type (voltage or current)
and for diagnostics, such as short-circuit (for voltage outputs) or upper/lower limit
diagnostics. You do not configure ranges of analog inputs and outputs in engineering
units on the Properties dialog. You must handle this in your program logic as described in
the topic "Processing of analog values (Page 83)".
● I/O diagnostic addresses: Configures the start address for the set of inputs and outputs of
the module

Configuring a communication interface (CM, CP or CB)

Depending on the type of communication interface, you configure the parameters for the
network.

5.6

Configuring the CPU for communication

5.6.1

Creating a network connection
Use the "Network view" of Device configuration to create the network connections between
the devices in your project. After creating the network connection, use the "Properties" tab of
the inspector window to configure the parameters of the network.
Table 5- 3

Creating a network connection

Action

Result

Select "Network view" to display the
devices to be connected.

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Action

Result

Select the port on one device and
drag the connection to the port on
the second device.

Release the mouse button to create
the network connection.

5.6.2

Configuring the Local/Partner connection path
The inspector window displays the properties of the connection whenever you have selected
any part of the instruction. Specify the communication parameters in the "Configuration" tab
of the "Properties" for the communication instruction.

Table 5- 4

Configuring the connection path (using the properties of the instruction)

TCP, ISO-on-TCP, and UDP

Connection properties

For the TCP, ISO-on-TCP, and UDP Ethernet
protocols, use the "Properties" of the instruction
(TSEND_C, TRCV_C, or TCON) to configure the
"Local/Partner" connections.
The illustration shows the "Connection
properties" of the "Configuration tab" for an ISOon-TCP connection.

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Note
When you configure the connection properties for one CPU, STEP 7 allows you either to
select a specific connection DB in the partner CPU (if one exists), or to create the connection
DB for the partner CPU. The partner CPU must already have been created for the project
and cannot be an "unspecified" CPU.
You must still insert a TSEND_C, TRCV_C or TCON instruction into the user program of the
partner CPU. When you insert the instruction, select the connection DB that was created by
the configuration.

Table 5- 5

Configuring the connection path for S7 communication (Device configuration)

S7 communication (GET and PUT)

Connection properties

For S7 communication, use the "Devices &
networks" editor of the network to configure the
Local/Partner connections. You can click the
"Highlighted: Connection" button to access the
"Properties".
The "General" tab provides several properties:


"General" (shown)



"Local ID"



"Special connection properties"



"Address details" (shown)

Refer to "Protocols" (Page 364) in the "PROFINET" section or to "Creating an S7
connection" (Page 415) in the "S7 communication" section for more information and a list of
available communication instructions.

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Table 5- 6

Parameters for the multiple CPU connection

Parameter

Definition

Address
General

Address
details

Assigned IP addresses
End point

Name assigned to the partner (receiving) CPU

Interface

Name assigned to the interfaces

Subnet

Name assigned to the subnets

Interface type

S7 communication only: Type of interface

Connection type

Type of Ethernet protocol

Connection ID

ID number

Connection data

Local and Partner CPU data storage location

Establish active
connection

Radio button to select Local or Partner CPU as the active connection

End point

S7 communication only: Name assigned to the partner (receiving) CPU

Rack/slot

S7 communication only: Rack and slot location

Connection resource

S7 communication only: Component of the TSAP used when configuring an

Port (decimal):

TCP and UPD: Partner CPU port in decimal format

TSAP 1 and Subnet ID:

ISO on TCP (RFC 1006) and S7 communication: Local and partner CPU
TSAPs in ASCII and hexadecimal formats

S7 connection with an S7-300 or S7-400 CPU

When configuring a connection with an S7-1200 CPU for ISO-on-TCP, use only ASCII characters in the TSAP extension
for the passive communication partners.

Transport Service Access Points (TSAPs)
Using TSAPs, ISO on TCP protocol and S7 communication allows multiple connections to a
single IP address (up to 64K connections). TSAPs uniquely identify these communication
end point connections to an IP address.
In the "Address Details" section of the Connection Parameters dialog, you define the TSAPs
to be used. The TSAP of a connection in the CPU is entered in the "Local TSAP" field. The
TSAP assigned for the connection in your partner CPU is entered under the "Partner TSAP"
field.

Port Numbers
With TCP and UDP protocols, the connection parameter configuration of the Local (active)
connection CPU must specify the remote IP address and port number of the Partner
(passive) connection CPU.
In the "Address Details" section of the Connection Parameters dialog, you define the ports to
be used. The port of a connection in the CPU is entered in the "Local Port" field. The port
assigned for the connection in your partner CPU is entered under the "Partner Port" field.

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5.6.3

Parameters for the PROFINET connection
The TSEND_C, TRCV_C and TCON instructions require that connection-related parameters
be specified in order to connect to the partner device. These parameters are specified by the
TCON_Param structure for the TCP, ISO-on-TCP and UDP protocols. Typically, you use the
"Configuration" tab of the "Properties" (Page 110) of the instruction to specify these
parameters. If the "Configuration" tab is not accessible, then you must specify the
TCON_Param structure programmatically.

Table 5- 7
Byte

Structure of the connection description (TCON_Param)
Parameter and data type

Description

0…1

block_length

UInt

Length: 64 bytes (fixed)

2…3

CONN_OUC
(Word)

Reference to this connection: Range of values: 1 (default) to 4095.
Specify the value of this parameter for the TSEND_C, TRCV_C or
TCON instruction under ID.

connection_type

USInt

Connection type:

active_est

Bool



17: TCP (default)



18: ISO-on-TCP



19: UDP

ID for the type of connection:




TCP and ISO-on-TCP:
–

FALSE: Passive connection

–

TRUE: Active connection (default)

UDP: FALSE

local_device_id

USInt

ID for the local PROFINET or Industrial Ethernet interface:
1 (default)

local_tsap_id_len

USIn

Length of parameter local_tsap_id used, in bytes; possible values:


TCP: 0 (active, default) or 2 (passive)



ISO-on-TCP: 2 to 16



UDP: 2

rem_subnet_id_len

USInt

This parameter is not used.

rem_staddr_len

USInt

Length of address of partner end point, in bytes:

rem_tsap_id_len

next_staddr_len

USInt



0: unspecified (parameter rem_staddr is irrelevant)



4 (default): Valid IP address in parameter rem_staddr (only for
TCP and ISO-on-TCP)

Length of parameter rem_tsap_id used, in bytes; possible values:


TCP: 0 (passive) or 2 (active, default)



ISO-on-TCP: 2 to 16



UDP: 0

This parameter is not used.

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Byte

Parameter and data type

12 … 27

local_tsap_id

Description
Array [1..16] of
Byte

Local address component of connection:




TCP and ISO-on-TCP: local port no. (possible values: 1 to
49151; recommended values: 2000...5000):
–

local_tsap_id[1] = high byte of port number in hexadecimal
notation;

–

local_tsap_id[2] = low byte of port number in hexadecimal
notation;

–

local_tsap_id[3-16] = irrelevant

ISO-on-TCP: local TSAP-ID:
–

local_tsap_id[1] = B#16#E0;

–

local_tsap_id[2] = rack and slot of local end points (bits 0 to
4: slot number, bits 5 to 7: rack number);

–

local_tsap_id[3-16] = TSAP extension, optional

 UDP: This parameter is not used.
Note: Make sure that every value of local_tsap_id is unique within
the CPU.
28 … 33

rem_subnet_id

Array [1..6] of
USInt

This parameter is not used.

34 … 39

rem_staddr

Array [1..6] of
USInt

TCP and ISO-on-TCP only: IP address of the partner end point.
(Not relevant for passive connections.) For example, IP address
192.168.002.003 is stored in the following elements of the array:
rem_staddr[1] = 192
rem_staddr[2] = 168
rem_staddr[3] = 002
rem_staddr[4] = 003
rem_staddr[5-6]= irrelevant

40 … 55

rem_tsap_id

Array [1..16] of
Byte

Partner address component of connection




TCP: partner port number. Range: 1 to 49151; Recommended
values: 2000 to 5000):
–

rem_tsap_id[1] = high byte of the port number in
hexadecimal notation

–

rem_tsap_id[2] = low byte of the port number in
hexadecimal notation;

–

rem_tsap_id[3-16] = irrelevant

ISO-on-TCP: partner TSAP-ID:
–

rem_tsap_id[1] = B#16#E0

–

rem_tsap_id[2] = rack and slot of partner end point (bits 0 to
4: Slot number, bits 5 to 7: rack number)

–

rem_tsap_id[3-16] = TSAP extension, optional

UDP: This parameter is not used.

56 … 61

next_staddr

Array [1..6] of
Byte

This parameter is not used.

62 … 63

spare

Word

Reserved: W#16#0000

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5.6.4

Assigning Internet Protocol (IP) addresses

5.6.4.1

Assigning IP addresses to programming and network devices
If your programming device is using an on-board adapter card connected to your plant LAN
(and possibly the world-wide web), the IP Address Network ID and subnet mask of your CPU
and the programming device's on-board adapter card must be exactly the same. The
Network ID is the first part of the IP address (first three octets) (for example, 211.154.184.16)
that determines what IP network you are on. The subnet mask normally has a value of
255.255.255.0; however, since your computer is on a plant LAN, the subnet mask may have
various values (for example, 255.255.254.0) in order to set up unique subnets. The subnet
mask, when combined with the device IP address in a mathematical AND operation, defines
the boundaries of an IP subnet.
Note
In a world-wide web scenario, where your programming devices, network devices, and IP
routers will communicate with the world, unique IP addresses must be assigned to avoid
conflict with other network users. Contact your company IT department personnel, who are
familiar with your plant networks, for assignment of your IP addresses.
If your programming device is using an Ethernet-to-USB adapter card connected to an
isolated network, the IP Address Network ID and subnet mask of your CPU and the
programming device's Ethernet-to-USB adapter card must be exactly the same. The Network
ID is the first part of the IP address (first three octets) (for example, 211.154.184.16) that
determines what IP network you are on. The subnet mask normally has a value of
255.255.255.0. The subnet mask, when combined with the device IP address in a
mathematical AND operation, defines the boundaries of an IP subnet.
Note
An Ethernet-to-USB adapter card is useful when you do not want your CPU on your
company LAN. During initial testing or commissioning tests, this arrangement is particularly
useful.

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Table 5- 8

Assigning Ethernet addresses

Programming Device Network Type
Adapter Card

Internet Protocol (IP) Address

Subnet Mask

On-board adapter
card

Network ID of your CPU and the
programming device's on-board
adapter card must be exactly the
same.

The subnet mask of your CPU and the
on-board adapter card must be exactly
the same.

Ethernet-to-USB
adapter card

Connected to
your plant LAN
(and possibly
the world-wide
web)

The Network ID is the first part of the
IP address (first three octets) (for
example, 211.154.184.16) that
determines what IP network you are
on.)

Connected to an Network ID of your CPU and the
isolated network programming device's Ethernet-toUSB adapter card must be exactly
the same.
The Network ID is the first part of the
IP address (first three octets) (for
example, 211.154.184.16) that
determines what IP network you are
on.)

The subnet mask normally has a value of
255.255.255.0; however, since your
computer is on a plant LAN, the subnet
mask may have various values (for
example, 255.255.254.0) in order to set
up unique subnets. The subnet mask,
when combined with the device IP
address in a mathematical AND
operation, defines the boundaries of an
IP subnet.
The subnet mask of your CPU and the
Ethernet-to-USB adapter card must be
exactly the same.
The subnet mask normally has a value of
255.255.255.0. The subnet mask, when
combined with the device IP address in a
mathematical AND operation, defines the
boundaries of an IP subnet.

Assigning or checking the IP address of your programming device using "My Network Places" (on
your desktop)
You can assign or check your programming device's IP address with the following menu
selections:
● (Right-click) "My Network Places"
● "Properties"
● (Right-click) "Local Area Connection"
● "Properties"
In the "Local Area Connection Properties" dialog, in the "This connection uses the following
items:" field, scroll down to "Internet Protocol (TCP/IP)". Click "Internet Protocol (TCP/IP)",
and click the "Properties" button. Select "Obtain an IP address automatically (DHCP)" or
"Use the following IP address" (to enter a static IP address).
Note
Dynamic Host Configuration Protocol (DHCP) automatically assigns an IP address to your
programming device upon power up from the DHCP server.

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5.6.4.2

Checking the IP address of your programming device
You can check the MAC and IP addresses of your programming device with the following
menu selections:
1. In the "Project tree", expand "Online access".
2. Right-click the required network, and select "Properties".
3. In the network dialog, expand "Configurations", and select "Industrial Ethernet".
The MAC and IP addresses of the programming device are displayed.

5.6.4.3

Assigning an IP address to a CPU online
You can assign an IP address to a network device online. This is particularly useful in an
initial device configuration.
1 In the "Project tree," verify that
no IP address is assigned to the
CPU, with the following menu
selections:
 "Online access"

 "Update accessible devices"

NOTE: If a MAC address is
shown instead of an IP
address, then no IP
address has been
assigned.

2. Under the required accessible
device, double-click "Online &
diagnostics".

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3. In the "Online & diagnostics"
dialog, make the following menu
selections:
 "Functions"
 "Assign IP address"

4. In the "IP address" field, enter
your new IP address, and click
the "Assign IP address" button.

5. In the "Project tree," verify that
your new IP address has been
assigned to the CPU, with the
following menu selections:
 "Online access"

 "Update accessible devices"

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5.6 Configuring the CPU for communication

5.6.4.4

Configuring an IP address for a CPU in your project

Configuring the PROFINET interface
To configure parameters for the PROFINET interface, select the green PROFINET box on
the CPU. The "Properties" tab in the inspector window displays the PROFINET port.

①

PROFINET port

Configuring the IP address
Ethernet (MAC) address: In a PROFINET network, each device is assigned a Media Access
Control address (MAC address) by the manufacturer for identification. A MAC address
consists of six groups of two hexadecimal digits, separated by hyphens (-) or colons (:), in
transmission order, (for example, 01-23-45-67-89-AB or 01:23:45:67:89:AB).
IP address: Each device must also have an Internet Protocol (IP) address. This address
allows the device to deliver data on a more complex, routed network.
Each IP address is divided into four 8-bit segments and is expressed in a dotted, decimal
format (for example, 211.154.184.16). The first part of the IP address is used for the Network
ID (What network are you on?), and the second part of the address is for the Host ID (unique
for each device on the network). An IP address of 192.168.x.y is a standard designation
recognized as part of a private network that is not routed on the Internet.
Subnet mask: A subnet is a logical grouping of connected network devices. Nodes on a
subnet tend to be located in close physical proximity to each other on a Local Area Network
(LAN). A mask (known as the subnet mask or network mask) defines the boundaries of an IP
subnet.
A subnet mask of 255.255.255.0 is generally suitable for a small local network. This means
that all IP addresses on this network should have the same first 3 octets, and the various
devices on this network are identified by the last octet (8-bit field). An example of this is to
assign a subnet mask of 255.255.255.0 and an IP addresses of 192.168.2.0 through
192.168.2.255 to the devices on a small local network.
The only connection between different subnets is via a router. If subnets are used, an IP
router must be employed.
IP router: Routers are the link between LANs. Using a router, a computer in a LAN can send
messages to any other networks, which might have other LANs behind them. If the
destination of the data is not within the LAN, the router forwards the data to another network
or group of networks where it can be delivered to its destination.
Routers rely on IP addresses to deliver and receive data packets.
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IP addresses properties: In
the Properties window,
select the "Ethernet
addresses" configuration
entry. STEP 7 displays the
Ethernet address
configuration dialog, which
associates the software
project with the IP address
of the CPU that will receive
that project.

Note
All IP addresses are configured when you download the project. If the CPU does not have a
pre-configured IP address, you must associate the project with the MAC address of the
target device. If your CPU is connected to a router on a network, you must also enter the IP
address of the router.
The "Set IP address using a different method" radio button allows you to change the IP
address online or by using the "T_CONFIG (Page 384)" instruction after the program is
downloaded. This IP address assignment method is for the CPU only.
WARNING
When changing the IP address of a CPU online or from the user program, it is possible to
create a condition in which the PROFINET network may stop.
If the IP address of a CPU is changed to an IP address outside the subnet, the PROFINET
network will lose communication, and all data exchange will stop. User equipment may be
configured to keep running under these conditions. Loss of PROFINET communication may
result in unexpected machine or process operations, causing death, severe personal injury,
or property damage if proper precautions are not taken.
If an IP address must be changed manually, ensure that the new IP address lies within the
subnet.

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Table 5- 9

Parameters for the IP address

Parameter
Subnet

IP protocol

5.6.5

Description
Name of the Subnet to which the device is connected. Click the "Add new subnet" button to create a
new subnet. "Not connected" is the default. Two connection types are possible:


The "Not connected" default provides a local connection.



A subnet is required when your network has two or more devices.

IP address

Assigned IP address for the CPU

Subnet mask

Assigned subnet mask

Use IP router

Click the checkbox to indicate the use of an IP router

Router address

Assigned IP address for the router, if applicable

Testing the PROFINET network
After completing the configuration, download the project (Page 142) to the CPU. All IP
addresses are configured when you download the project.

Assigning an IP address to a device online
The S7-1200 CPU does not have a pre-configured IP address. You must manually assign an
IP address for the CPU:
● To assign an IP address to a device online, refer to "Device configuration: Assigning an
IP address to a CPU online" (Page 117) for this step-by-step procedure.
● To assign an IP address in your project, you must configure the IP address in the Device
configuration, save the configuration, and download it to the PLC. Refer to "Device
configuration: Configuring an IP address for a CPU in your project" (Page 119) for more
information.

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Using the "Extended download to device" dialog to test for connected network devices
The S7-1200 CPU "Download to device" function and its "Extended download to device"
dialog can show all accessible network devices and whether or not unique IP addresses
have been assigned to all devices. To display all accessible and available devices with their
assigned MAC or IP addresses, check the "Show all accessible devices" checkbox.

If the required network device is not in this list, communications to that device have been
interrupted for some reason. The device and network must be investigated for hardware
and/or configuration errors.

5.6.6

Locating the Ethernet (MAC) address on the CPU
In PROFINET networking, a Media Access Control address (MAC address) is an identifier
assigned to the network interface by the manufacturer for identification. A MAC address
usually encodes the manufacturer's registered identification number.
The standard (IEEE 802.3) format for printing MAC addresses in human-friendly form is six
groups of two hexadecimal digits, separated by hyphens (-) or colons (:), in transmission
order, (for example, 01-23-45-67-89-ab or 01:23:45:67:89:ab).
Note
Each CPU is loaded at the factory with a permanent, unique MAC address. You cannot
change the MAC address of a CPU.
The MAC address is printed on the front, lower-left corner of the CPU. Note that you have to
lift the lower TB doors to see the MAC address information.

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5.6 Configuring the CPU for communication

①

MAC address

Initially, the CPU has no IP address, only a factory-installed MAC address. PROFINET
communications requires that all devices be assigned a unique IP address.
Use the CPU "Download to
device" function and the
"Extended download to device"
dialog to show all accessible
network devices and ensure that
unique IP addresses have been
assigned to all devices. This
dialog displays all accessible and
available devices with their
assigned MAC or IP addresses.
MAC addresses are all-important
in identifying devices that are
missing the required unique IP
address.

5.6.7

Configuring Network Time Protocol synchronization
The Network Time Protocol (NTP) is widely used to synchronize the clocks of computer
systems to Internet time servers. In NTP mode, the CP sends time-of-day queries at regular
intervals (in the client mode) to the NTP server in the subnet (LAN). Based on the replies
from the server, the most reliable and most accurate time is calculated and the time of day
on the station is synchronized.
The advantage of this mode is that it allows the time to be synchronized across subnets.
The IP addresses of up to four NTP servers need to be configured. The update interval
defines the interval between the time queries (in seconds). The value of the interval ranges
between 10 seconds and one day.

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5.6 Configuring the CPU for communication
In NTP mode, it is generally UTC (Universal Time Coordinated) that is transferred; this
corresponds to GMT (Greenwich Mean Time).
In the Properties window, select the "Time synchronization" configuration entry. STEP 7
displays the Time synchronization configuration dialog:

Note
All IP addresses are configured when you download the project.

Table 5- 10

5.6.8

Parameters for time synchronization

Parameter

Definition

Enable time-of-day
synchronization using Network
Time Protocol (NTP) servers

Click the checkbox to enable time-of-day synchronization using
NTP servers.

Server 1

Assigned IP Address for network time server 1

Server 2

Assigned IP Address for network time server 2

Server 3

Assigned IP Address for network time server 3

Server 4

Assigned IP Address for network time server 4

Time synchronization interval

Interval value (sec)

PROFINET device start-up time, naming, and address assignment
PROFINET IO can extend the start-up time for your system (configurable time-out figure).
More devices and slow devices impact the amount of time it takes to switch to RUN. There is
a maximum of 8 IO devices on the S7-1200 PROFINET network.
Each station (or IO device) starts up independently on start-up, and this affects the overall
CPU start-up time. If you set the configurable time-out too low, there may not be a sufficient
overall CPU start-up time for all stations to complete start-up. If this situation occurs, false
station errors will result.
The default configurable time-out is 1 minute; the user can configure this time.

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PROFINET device naming and addressing in STEP 7
All PROFINET devices must have a Device Name and an IP Address. Use STEP 7 to define
the Device Names and to configure the IP addresses. Device names are downloaded to the
IO devices using PROFINET DCP (Discovery and Configuration Protocol).

PROFINET address assignment at system start-up
The controller broadcasts the names of the devices to the network, and the devices respond
with their MAC addresses. The controller then assigns an IP address to the device using
PROFINET DCP protocol:
● If the MAC address has a configured IP address, then the station performs start-up.
● If the MAC address does not have a configured IP address, STEP 7 assigns the address
that is configured in the project, and the station then performs start-up.
● If there is a problem with this process, a station error occurs and no start-up takes place.
This situation causes the configurable time-out value to be exceeded.

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5.6 Configuring the CPU for communication

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6.1

Guidelines for designing a PLC system
When designing a PLC system, you can choose from a variety of methods and criteria. The
following general guidelines can apply to many design projects. Of course, you must follow
the directives of your own company's procedures and the accepted practices of your own
training and location.

Table 6- 1

Guidelines for designing a PLC system

Recommended steps

Tasks

Partition your process
or machine

Divide your process or machine into sections that have a level of independence from each other.
These partitions determine the boundaries between controllers and influence the functional
description specifications and the assignment of resources.

Create the functional
specifications

Write the descriptions of operation for each section of the process or machine, such as the I/O
points, the functional description of the operation, the states that must be achieved before
allowing action for each actuator (such as a solenoid, a motor, or a drive), a description of the
operator interface, and any interfaces with other sections of the process or machine.

Design the safety
circuits

Identify any equipment that might require hard-wired logic for safety. Remember that control
devices can fail in an unsafe manner, which can produce unexpected startup or change in the
operation of machinery. Where unexpected or incorrect operation of the machinery could result in
physical injury to people or significant property damage, consider the implementation of
electromechanical overrides (which operate independently of the PLC) to prevent unsafe
operations. The following tasks should be included in the design of safety circuits:

Specify the operator
stations



Identify any improper or unexpected operation of actuators that could be hazardous.



Identify the conditions that would assure the operation is not hazardous, and determine how
to detect these conditions independently of the PLC.



Identify how the PLC affects the process when power is applied and removed, and also
identify how and when errors are detected. Use this information only for designing the normal
and expected abnormal operation. You should not rely on this "best case" scenario for safety
purposes.



Design the manual or electromechanical safety overrides that block the hazardous operation
independent of the PLC.



Provide the appropriate status information from the independent circuits to the PLC so that
the program and any operator interfaces have necessary information.



Identify any other safety-related requirements for safe operation of the process.

Based on the requirements of the functional specifications, create the following drawings of the
operator stations:


Overview drawing that shows the location of each operator station in relation to the process
or machine.



Mechanical layout drawing of the devices for the operator station, such as display, switches,
and lights.



Electrical drawings with the associated I/O of the PLC and signal modules.

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6.2 Structuring your user program

Recommended steps

Tasks

Create the
configuration drawings

Based on the requirements of the functional specification, create configuration drawings of the
control equipment:

Create a list of
symbolic names

6.2



Overview drawing that shows the location of each PLC in relation to the process or machine.



Mechanical layout drawing of each PLC and any I/O modules, including any cabinets and
other equipment.



Electrical drawings for each PLC and any I/O modules, including the device model numbers,
communications addresses, and I/O addresses.

Create a list of symbolic names for the absolute addresses. Include not only the physical I/O
signals, but also the other elements (such as tag names) to be used in your program.

Structuring your user program
When you create a user program for the automation tasks, you insert the instructions for the
program into code blocks:
● An organization block (OB) responds to a specific event in the CPU and can interrupt the
execution of the user program. The default for the cyclic execution of the user program
(OB 1) provides the base structure for your user program and is the only code block
required for a user program. If you include other OBs in your program, these OBs
interrupt the execution of OB 1. The other OBs perform specific functions, such as for
startup tasks, for handling interrupts and errors, or for executing specific program code at
specific time intervals.
● A function block (FB) is a subroutine that is executed when called from another code
block (OB, FB, or FC). The calling block passes parameters to the FB and also identifies
a specific data block (DB) that stores the data for the specific call or instance of that FB.
Changing the instance DB allows a generic FB to control the operation of a set of
devices. For example, one FB can control several pumps or valves, with different
instance DBs containing the specific operational parameters for each pump or valve.
● A function (FC) is a subroutine that is executed when called from another code block
(OB, FB, or FC). The FC does not have an associated instance DB. The calling block
passes parameters to the FC. The output values from the FC must be written to a
memory address or to a global DB.

Choosing the type of structure for your user program
Based on the requirements of your application, you can choose either a linear structure or a
modular structure for creating your user program:
● A linear program executes all of the instructions for your automation tasks in sequence,
one after the other. Typically, the linear program puts all of the program instructions into
the OB for the cyclic execution of the program (OB 1).
● A modular program calls specific code blocks that perform specific tasks. To create a
modular structure, you divide the complex automation task into smaller subordinate tasks
that correspond to the technological functions of the process. Each code block provides
the program segment for each subordinate task. You structure your program by calling
one of the code blocks from another block.

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6.3 Using blocks to structure your program

Linear structure:
2%

Modular structure:
2%

By creating generic code blocks that can be reused within the user program, you can simplify
the design and implementation of the user program. Using generic code blocks has a
number of benefits:
● You can create reusable blocks of code for standard tasks, such as for controlling a pump
or a motor. You can also store these generic code blocks in a library that can be used by
different applications or solutions.
● When you structure the user program into modular components that relate to functional
tasks, the design of your program can be easier to understand and to manage. The
modular components not only help to standardize the program design, but can also help
to make updating or modifying the program code quicker and easier.
● Creating modular components simplifies the debugging of your program. By structuring
the complete program as a set of modular program segments, you can test the
functionality of each code block as it is developed.
● Creating modular components that relate to specific technological functions can help to
simplify and reduce the time involved with commissioning the completed application.

6.3

Using blocks to structure your program
By designing FBs and FCs to perform generic tasks, you create modular code blocks. You
then structure your program by having other code blocks call these reusable modules. The
calling block passes device-specific parameters to the called block.
When a code block calls another code block, the CPU executes the program code in the
called block. After execution of the called block is complete, the CPU resumes the execution
of the calling block. Processing continues with execution of the instruction that follows after
the block call.

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Programming concepts
6.3 Using blocks to structure your program

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2%)%)&

࿇
2%)%)&
ི

཰

ཱ

Calling block

Called (or interrupting) block

①
②

Program execution

③
④

Program execution

Instruction or event that initiates the execution
of another block
Block end (returns to calling block)

ཱི

You can nest the block calls for a more modular structure. In the following example, the
nesting depth is 4: the program cycle OB plus 3 layers of calls to code blocks.

཰
2%

①
②

ཱ
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Start of cycle
Nesting depth

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6.3.1

Organization block (OB)
Organization blocks provide structure for your program. They serve as the interface between
the operating system and the user program. OBs are event driven. An event, such as a
diagnostic interrupt or a time interval, will cause the CPU to execute an OB. Some OBs have
predefined start events and behavior.
The program cycle OB contains your main program. You can include more than one program
cycle OB in your user program. During RUN mode, the program cycle OBs execute at the
lowest priority level and can be interrupted by all other types of program processing. The
startup OB does not interrupt the program cycle OB because the CPU executes the startup
OB before going to RUN mode.
After finishing the processing of the program cycle OBs, the CPU immediately executes the
program cycle OBs again. This cyclic processing is the "normal" type of processing used for
programmable logic controllers. For many applications, the entire user program is located in
a single program cycle OB.
You can create other OBs to perform specific functions, such as for handling interrupts and
errors, or for executing specific program code at specific time intervals. These OBs interrupt
the execution of the program cycle OBs.
Use the "Add new block" dialog to create new OBs in your user program.
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6.3 Using blocks to structure your program

Interrupt handling is always eventdriven. When such an event occurs,
the CPU interrupts the execution of
the user program and calls the OB
that was configured to handle that
event. After finishing the execution
of the interrupting OB, the CPU
resumes the execution of the user
program at the point of interruption.

The CPU determines the order for handling interrupt events by a priority assigned to each
OB. Each event has a particular servicing priority. The respective priority level within a
priority class determines the order in which the OBs of that priority group are executed.
Several interrupt events can be combined into priority classes. For more information, refer to
the PLC concepts chapter section on execution of the user program (Page 61).

Creating an additional OB within a class of OB
You can create multiple OBs for your user program, even for the program cycle and startup
OB classes. Use the "Add new block" dialog to create an OB. Enter the name for your OB
and enter an OB number 200 or greater.
If you create multiple program cycle OBs for your user program, the CPU executes each
program cycle OB in numerical sequence, starting with the program cycle OB with the lowest
number (such as OB 1). For example: after first program cycle OB (such as OB1) finishes,
the CPU executes the next higher program cycle OB (such as OB 200).

Configuring the operation of an OB
You can modify the operational
parameters for an OB. For example, you
can configure the time parameter for a
time-delay OB or for a cyclic OB.

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6.3 Using blocks to structure your program

6.3.2

Function (FC)
A function (FC) is a code block that typically performs a specific operation on a set of input
values. The FC stores the results of this operation in memory locations. For example, use
FCs to perform standard and reusable operations (such as for mathematical calculations) or
technological functions (such as for individual controls using bit logic operations). An FC can
also be called several times at different points in a program. This reuse simplifies the
programming of frequently recurring tasks.
An FC does not have an associated instance data block (DB). The FC uses the local data
stack for the temporary data used to calculate the operation. The temporary data is not
saved. To store data permanently, assign the output value to a global memory location, such
as M memory or to a global DB.

6.3.3

Function block (FB)
A function block (FB) is a code block that uses an instance data block for its parameters and
static data. FBs have variable memory that is located in a data block (DB), or "instance" DB.
The instance DB provides a block of memory that is associated with that instance (or call) of
the FB and stores data after the FB finishes. You can associate different instance DBs with
different calls of the FB. The instance DBs allow you to use one generic FB to control
multiple devices. You structure your program by having one code block make a call to an FB
and an instance DB. The CPU then executes the program code in that FB, and stores the
block parameters and the static local data in the instance DB. When the execution of the FB
finishes, the CPU returns to the code block that called the FB. The instance DB retains the
values for that instance of the FB. These values are available to subsequent calls to the
function block either in the same scan cycle or other scan cycles.

Reusable code blocks with associated memory
You typically use an FB to control the operation for tasks or devices that do not finish their
operation within one scan cycle. To store the operating parameters so that they can be
quickly accessed from one scan to the next, each FB in your user program has one or more
instance DBs. When you call an FB, you also specify an instance DB that contains the block
parameters and the static local data for that call or "instance" of the FB. The instance DB
maintains these values after the FB finishes execution.
By designing the FB for generic control tasks, you can reuse the FB for multiple devices by
selecting different instance DBs for different calls of the FB.
An FB stores the Input, Output, and InOut, and Static parameters in an instance DB.

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6.3 Using blocks to structure your program

Assigning the start value in the instance DB
The instance DB stores both a default value and a start value for each parameter. The start
value provides the value to be used when the FB is executed. The start value can then be
modified during the execution of your user program.
The FB interface also provides a "Default value" column that allows you to assign a new start
value for the parameter as you are writing the program code. This default value in the FB is
then transferred to the start value in the associated instance DB. If you do not assign a new
start value for a parameter in the FB interface, the default value from instance DB is copied
to start value.

Using a single FB with DBs
The following figure shows an OB that calls one FB three times, using a different data block
for each call. This structure allows one generic FB to control several similar devices, such as
motors, by assigning a different instance data block for each call for the different devices.
Each instance DB stores the data (such as speed, ramp-up time, and total operating time)
for an individual device.
'%

2%
)%
)%'%

)%'%
)%'%
'%

In this example, FB 22 controls three separate devices, with DB 201 storing the operational
data for the first device, DB 202 storing the operational data for the second device, and DB
203 storing the operational data for the third device.

6.3.4

Data block (DB)
You create data blocks (DB) in your user program to store data for the code blocks. All of the
program blocks in the user program can access the data in a global DB, but an instance DB
stores data for a specific function block (FB).
The data stored in a DB is not deleted when the execution of the associated code block
comes to an end. There are two types of DBs:
● A global DB stores data for the code blocks in your program. Any OB, FB, or FC can
access the data in a global DB.
● An instance DB stores the data for a specific FB. The structure of the data in an instance
DB reflects the parameters (Input, Output, and InOut) and the static data for the FB. (The
Temp memory for the FB is not stored in the instance DB.)

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Programming concepts
6.4 Understanding data consistency

Note
Although the instance DB reflects the data for a specific FB, any code block can access
the data in an instance DB.
You can configure a DB as being read-only:
1. Right-click the DB in the project navigator and select "Properties" from the context menu.
2. In the "Properties" dialog, select "Attributes".
3. Select the "Data block write-protected in the device" option and click "OK".

Creating reusable code blocks
Use the "Add new block" dialog
under "Program blocks" in the
Project navigator to create OBs,
FBs, FCs, and global DBs.
When you create a code block, you
select the programming language
for the block. You do not select a
language for a DB because it only
stores data.

6.4

Understanding data consistency
The CPU maintains the data consistency for all of the elementary data types (such as Words
or DWords) and all of the system-defined structures (for example, IEC_TIMERS or DTL).
The reading or writing of the value cannot be interrupted. (For example, the CPU protects
the access to a DWord value until the four bytes of the DWord have been read or written.) To
ensure that the program cycle OBs and the interrupt OBs cannot write to the same memory
location at the same time, the CPU does not execute an interrupt OB until the read or write
operation in the program cycle OB has been completed.
If your user program shares multiple values in memory between a program cycle OB and an
interrupt OB, your user program must also ensure that these values are modified or read
consistently. You can use the DIS_AIRT (disable alarm interrupt) and EN_AIRT (enable
alarm interrupt) instructions in your program cycle OB to protect any access to the shared
values.
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Programming concepts
6.5 Programming language
● Insert a DIS_AIRT instruction in the code block to ensure that an interrupt OB cannot be
executed during the read or write operation.
● Insert the instructions that read or write the values that could be altered by an interrupt
OB.
● Insert an EN_AIRT instruction at the end of the sequence to cancel the DIS_AIRT and
allow the execution of the interrupt OB.
A communication request from an HMI device or another CPU can also interrupt execution of
the program cycle OB. The communication requests can also cause issues with data
consistency. The CPU ensures that the elementary data types are always read and written
consistently by the user program instructions. Because the user program is interrupted
periodically by communications, it is not possible to guarantee that multiple values in the
CPU will all be updated at the same time by the HMI. For example, the values displayed on a
given HMI screen could be from different scan cycles of the CPU.
The PtP (Point-to-Point) instructions, PROFINET instructions (such as TSEND_C and
TRCV_C), and PROFIBUS instructions (Page 410) transfer buffers of data that could be
interrupted. Ensure the data consistency for the buffers of data by avoiding any read or write
operation to the buffers in both the program cycle OB and an interrupt OB. If it is necessary
to modify the buffer values for these instructions in an interrupt OB, use a DIS_AIRT
instruction to delay any interruption (an interrupt OB or a communication interrupt from an
HMI or another CPU) until an EN_AIRT instruction is executed.
Note
The use of the DIS_AIRT instruction delays the processing of interrupt OBs until the
EN_AIRT instruction is executed, affecting the interrupt latency (time from an event to the
time when the interrupt OB is executed) of your user program.

6.5

Programming language
STEP 7 provides the following standard programming languages for S7-1200:
● LAD (ladder logic) is a graphical programming language. The representation is based on
circuit diagrams (Page 136).
● FBD (Function Block Diagram) is a programming language that is based on the graphical
logic symbols used in Boolean algebra (Page 137).
When you create a code block, you select the programming language to be used by that
block. Your user program can utilize code blocks created in any or all of the programming
languages.

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Programming concepts
6.5 Programming language

6.5.1

Ladder logic (LAD)
The elements of a circuit diagram, such as normally closed and normally open contacts, and
coils are linked to form networks.

To create the logic for complex operations, you can insert branches to create the logic for
parallel circuits. Parallel branches are opened downwards or are connected directly to the
power rail. You terminate the branches upwards.
LAD provides "box" instructions for a variety of functions, such as math, timer, counter, and
move.
STEP 7 does not limit the number of instructions (rows and columns) in a LAD network.
Note
Every LAD network must terminate with a coil or a box instruction.
Consider the following rules when creating a LAD network:
● You cannot create a branch that could result in a power flow in the reverse direction.
$

(

)

● You cannot create a branch that would cause a short circuit.
$

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Programming concepts
6.5 Programming language

6.5.2

Function Block Diagram (FBD)
Like LAD, FBD is also a graphical programming language. The representation of the logic is
based on the graphical logic symbols used in Boolean algebra.
To create the logic for complex operations,
insert parallel branches between the boxes.

Mathematical functions and other complex functions can be represented directly in
conjunction with the logic boxes.
STEP 7 does not limit the number of instructions (rows and columns) in an FBD network.

6.5.3

EN and ENO for LAD and FBD

Determining "power flow" (EN and ENO) for an instruction
Certain instructions (such as the Math and the Move instructions) provide parameters for EN
and ENO. These parameters relate to power flow in LAD or FBD and determine whether the
instruction is executed during that scan.
● EN (Enable In) is a Boolean input. Power flow (EN = 1) must be present at this input for
the box instruction to be executed. If the EN input of a LAD box is connected directly to
the left power rail, the instruction will always be executed.
● ENO (Enable Out) is a Boolean output. If the box has power flow at the EN input and the
box executes its function without error, then the ENO output passes power flow
(ENO = 1) to the next element. If an error is detected in the execution of the box
instruction, then power flow is terminated (ENO = 0) at the box instruction that generated
the error.
Table 6- 2

Operands for EN and ENO

Program editor

Inputs/outputs

Operands

Data type

LAD

EN, ENO

Power flow

Bool

FBD

I, I:P, Q, M, DB, Temp, Power Flow

Bool

ENO

Power Flow

Bool

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Programming concepts
6.6 Protection

Effect of Ret_Val or Status parameters on ENO
Some instructions, such as the communication instructions or the string conversion
instructions, provide an output parameter that contains information about the processing of
the instruction. For example, some instructions provide a Ret_Val (return value) parameter,
which is typically an Int data type that contains status information in a range from -32768 to
+32767. Other instructions provide a Status parameter, which is typically a Word data type
that stores status information in a range of hexadecimal values from 16#0000 to 16#FFFF.
The numerical value stored in a Ret_Val or a Status parameter determines the state of ENO
for that instruction.
● Ret_Val: A value from 0 to 32767 typically sets ENO = 1 (or TRUE). A value from -32768
to -1 typically sets ENO = 0 (or FALSE). To evaluate Ret_Val, change the representation
to hexadecimal.
● Status: A value from 16#0000 16#7FFF typically sets ENO = 1 (or TRUE). A value from
16#8000 to 16#FFFF typically sets ENO = 0 (or FALSE).
Instructions that take more than one scan to execute often provide a Busy parameter (Bool)
to signal that the instruction is active but has not completed execution. These instructions
often also provide a Done parameter (Bool) and an Error parameter (Bool). Done signals that
the instruction was completed without error, and Error signals that the instruction was
completed with an error condition.
● When Busy = 1 (or TRUE), ENO = 1 (or TRUE).
● When Done = 1 (or TRUE), ENO = 1 (or TRUE).
● When Error = 1 (or TRUE), ENO = 0 (or FALSE).

6.6

Protection

6.6.1

Access protection for the CPU
The CPU provides 3 levels of security for restricting access to specific functions. When you
configure the security level and password for a CPU, you limit the functions and memory
areas that can be accessed without entering a password.
The password is case-sensitive.
To configure the password,
follow these steps:
1. In the "Device configuration",
select the CPU.
2. In the inspector window,
select the "Properties" tab.
3. Select the "Protection"
property to select the
protection level and to enter a
password.

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Programming concepts
6.6 Protection
Each level allows certain functions to be accessible without a password. The default
condition for the CPU is to have no restriction and no password-protection. To restrict access
to a CPU, you configure the properties of the CPU and enter the password.
Entering the password over a network does not compromise the password protection for the
CPU. A password-protected CPU allows only one user unrestricted access at a time.
Password protection does not apply to the execution of user program instructions including
communication functions. Entering the correct password provides access to all of the
functions.
PLC-to-PLC communications (using communication instructions in the code blocks) are not
restricted by the security level in the CPU. HMI functionality is also not restricted.
Table 6- 3

Security levels for the CPU

Security level

Access restrictions

No protection

Allows full access without password-protection.

Write protection

Allows HMI access and all forms of PLC-to-PLC communications without password-protection.
Password is required for modifying (writing to) the CPU and for changing the CPU mode
(RUN/STOP).

Read/write protection

Allows HMI access and all forms of PLC-to-PLC communications without password-protection.
Password is required for reading the data in the CPU, for modifying (writing to) the CPU, and for
changing the CPU mode (RUN/STOP).

6.6.2

Know-how protection
Know-how protection allows you to prevent one or more code blocks (OB, FB, FC, or DB) in
your program from unauthorized access. You create a password to limit access to the code
block. The password-protection prevents unauthorized reading or modification of the code
block. Without the password, you can read only the following information about the code
block:
● Block title, block comment, and block properties
● Transfer parameters (IN, OUT, IN_OUT, Return)
● Call structure of the program
● Global tags in the cross references (without information on the point of use), but local
tags are hidden
When you configure a block for "know-how" protection, the code within the block cannot be
accessed except after entering the password.
Use the "Properties" task card of the code block to configure the know-how protection for
that block. After opening the code block, select "Protection" from Properties.

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6.6 Protection

1. In the Properties for the code block, click
the "Protection" button to display the
"Know-how protection" dialog.
2. Click the "Define" button to enter the
password.

After entering and confirming the password,
click "OK".

6.6.3

Copy protection
An additional security feature allows you to bind the program or code blocks for use with a
specific memory card or CPU. This feature is especially useful for protecting your intellectual
property. When you bind a program or block to a specific device, you restrict the program or
code block for use only with a specific memory card or CPU. This feature allows you to
distribute a program or code block electronically (such as over the Internet or through email)
or by sending a memory cartridge.
Use the "Properties" task card of the code block to bind the block to a specific CPU or
memory card.

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6.6 Protection
1. After opening the code block, select "Protection".

2. From the drop-down list under "Copy protection" task, select the option to bind the code
block either to a memory card or to a specific CPU.

3. Select the type of copy protection and enter the serial number for the memory card or
CPU.
Note
The serial number is case-sensitive.

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6.7 Downloading the elements of your program

6.7

Downloading the elements of your program
You can download the elements of your project from the programming device to the CPU.
When you download a project, the CPU stores the user program (OBs, FCs, FBs and DBs)
in permanent memory.

You can download your project from the programming device to your CPU from any of the
following locations:
● "Project tree": Right-click the program element, and then click the context-sensitive
"Download" selection.
● "Online" menu: Click the "Download to device" selection.
● Toolbar: Click the "Download to device" icon.

6.8

Uploading from the CPU

6.8.1

Copying elements of the project
You can also copy the program blocks from an online CPU or a memory card attached to
your programming device.
Prepare the offline project for the copied program blocks:
1. Add a CPU device that matches the online CPU.
2. Expand the CPU node once so that the "Program
blocks" folder is visible.

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6.8 Uploading from the CPU
From the project navigator, expand the node for "Online
access" to select the program blocks in the online CPU:
1. Expand the node for the network, and double click
"Update accessible devices".
2. Expand the node for the CPU.
3. Drag the "Program blocks" folder from the online CPU
and drop the folder into the "Program blocks" folder of
your offline project.
4. In the "Upload preview" dialog, select the box for
"Continue", and then click the "Upload from device"
button.
When the upload is complete, all of the program blocks,
technology blocks, and tags will be displayed in the offline
area.

Note
You can copy the program blocks from the online CPU to an existing program. The
"Program-blocks" folder of the offline project does not have to be empty. However, the
existing program will be deleted and replaced by the user program from the online CPU.

6.8.2

Using the Synchronize function to upload
You can use the "Compare" editor in STEP 7 to synchronize the online and offline projects
and upload from the device to the project.

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6.9 Debugging and testing the program

6.9

Debugging and testing the program

6.9.1

Monitor and modify data in the CPU
As shown in the following table, you can monitor and modify values in the online CPU.
Table 6- 4

Monitoring and modifying data with STEP 7

Editor

Monitor

Modify

Force

Watch table

Yes

Force table

Yes

Program editor

Yes

Tag table

Yes

DB editor

Yes

Monitoring with a
watch table

Monitoring with the LAD editor

Refer to the "Online and diagnostics" chapter for more information about monitoring and
modifying data in the CPU (Page 552).

6.9.2

Watch tables and force tables
You use "watch tables" for monitoring and modifying the values of a user program being
executed by the online CPU. You can create and save different watch tables in your project
to support a variety of test environments. This allows you to reproduce tests during
commissioning or for service and maintenance purposes.
With a watch table, you can monitor and interact with the CPU as it executes the user
program. You can display or change values not only for the tags of the code blocks and data
blocks, but also for the memory areas of the CPU, including the inputs and outputs (I and Q),
peripheral inputs (I:P), bit memory (M), and data blocks (DB).
With the watch table, you can enable the physical outputs (Q:P) of a CPU in STOP mode.
For example, you can assign specific values to the outputs when testing the wiring for the
CPU.
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6.9 Debugging and testing the program
STEP 7 also provides a force table for "forcing" a tag to a specific value. For more
information about forcing, see the section on forcing values in the CPU (Page 559) in the
"Online and Diagnostics" chapter.
Note
The force values are stored in the CPU and not in the watch table.
You cannot force an input (or "I" address). However, you can force a peripheral input. To
force a peripheral input, append a ":P" to the address (for example: "On:P").

6.9.3

Cross reference to show usage
The Inspector window displays cross-reference information about how a selected object is
used throughout the complete project, such as the user program, the CPU and any HMI
devices. The "Cross-reference" tab displays the instances where a selected object is being
used and the other objects using it. The Inspector window also includes blocks which are
only available online in the cross-references. To display the cross-references, select the
"Show cross-references" command. (In the Project view, find the cross references in the
"Tools" menu.)
Note
You do not have to close the editor to see the cross-reference information.
You can sort the entries in the cross-reference. The cross-reference list provides an
overview of the use of memory addresses and tags within the user program.
● When creating and changing a program, you retain an overview of the operands, tags
and block calls you have used.
● From the cross-references, you can jump directly to the point of use of operands and
tags.
● During a program test or when troubleshooting, you are notified about which memory
location is being processed by which command in which block, which tag is being used in
which screen, and which block is called by which other block.
Table 6- 5

Elements of the cross reference

Column

Description

Object

Name of the object that uses the lower-level objects or that is being used by the
lower-level objects

Quantity

Number of uses

Location

Each location of use, for example, network

Property

Special properties of referenced objects, for example, the tag names in multi-instance
declarations

Shows additional information about the object, such as whether an instance DB is
used as template or as a multiple instance

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6.9.4

Column

Description

Access

Type of access, whether access to the operand is read access (R) and/or write
access (W)

Address

Address of the operand

Type

Information on the type and language used to create the object

Path

Path of object in project tree

Call structure to examine the calling hierarchy
The call structure describes the call hierarchy of the block within your user program. It
provides an overview of the blocks used, calls to other blocks, the relationships between
blocks, the data requirements for each block, and the status of the blocks. You can open the
program editor and edit blocks from the call structure.
Displaying the call structure provides you with a list of the blocks used in the user program.
STEP 7 highlights the first level of the call structure and displays any blocks that are not
called by any other block in the program. The first level of the call structure displays the OBs
and any FCs, FBs, and DBs that are not called by an OB. If a code block calls another block,
the called block is shown as an indentation under the calling block. The call structure only
displays those blocks that are called by a code block.
You can selectively display only the blocks causing conflicts within the call structure. The
following conditions cause conflicts:
● Blocks that execute any calls with older or newer code time stamps
● Blocks that call a block with modified interface
● Blocks that use a tag with modified address and/or data type
● Blocks that are called neither directly nor indirectly by an OB
● Blocks that call a non-existent or missing block
You can group several block calls and data blocks as a group. You use a drop-down list to
see the links to the various call locations.
You can also perform a consistency check to show time stamp conflicts. Changing the time
stamp of a block during or after the program is generated can lead to time stamp conflicts,
which in turn cause inconsistencies among the blocks that are calling and being called.
● Most time stamp and interface conflicts can be corrected by recompiling the code blocks.
● If compilation fails to clear up inconsistencies, use the link in the "Details" column to go to
the source of the problem in the program editor. You can then manually eliminate any
inconsistencies.
● Any blocks marked in red must be recompiled.

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7.1

Bit logic

7.1.1

Bit logic contacts and coils
LAD and FBD are very effective for handling Boolean logic.

LAD contacts
Table 7- 1
LAD

Normally open and normally closed contacts
Description
Normally open and normally closed contacts: You can connect contacts to other contacts and create
your own combination logic. If the input bit you specify uses memory identifier I (input) or Q (output),
then the bit value is read from the process-image register. The physical contact signals in your control
process are wired to I terminals on the PLC. The CPU scans the wired input signals and continuously
updates the corresponding state values in the process-image input register.
You can specify an immediate read of a physical input using ":P" following the I offset (example:
"%I3.4:P"). For an immediate read, the bit data values are read directly from the physical input instead
of the process image. An immediate read does not update the process image.

Table 7- 2

Data types for the parameters

Parameter

Data type

Description

Bool

Assigned bit

● The Normally Open contact is closed (ON) when the assigned bit value is equal to 1.
● The Normally Closed contact is closed (ON) when the assigned bit value is equal to 0.
● Contacts connected in series create AND logic networks.
● Contacts connected in parallel create OR logic networks.

FBD AND, OR, and XOR boxes
In FBD programming, LAD contact networks are transformed into AND (&), OR (>=1), and
exclusive OR (x) box networks where you can specify bit values for the box inputs and
outputs. You may also connect to other logic boxes and create your own logic combinations.
After the box is placed in your network, you can drag the "Insert binary input" tool from the
"Favorites" toolbar or instruction tree and then drop it onto the input side of the box to add
more inputs. You can also right-click on the box input connector and select "Insert input".

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7.1 Bit logic
Box inputs and outputs can be connected to another logic box, or you can enter a bit
address or bit symbol name for an unconnected input. When the box instruction is executed,
the current input states are applied to the binary box logic and, if true, the box output will be
true.
Table 7- 3

AND, OR, and XOR boxes

FBD

Description
All inputs of an AND box must be TRUE for the output to be TRUE.

Any input of an OR box must be TRUE for the output to be TRUE.

An odd number of the inputs of an XOR box must be TRUE for the output to be TRUE.

Table 7- 4

Data types for the parameters

Parameter

Data type

Description

IN1, IN2

Bool

Input bit

NOT logic inverter
Table 7- 5
LAD

NOT Logic inverter
FBD

Description
For FBD programming, you can drag the "Negate binary input" tool from the
"Favorites" toolbar or instruction tree and then drop it on an input or output to
create a logic inverter on that box connector.
The LAD NOT contact inverts the logical state of power flow input.


If there is no power flow into the NOT contact, then there is power flow out.



If there is power flow into the NOT contact, then there is no power flow out.

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7.1 Bit logic

Output coil and assignment box
The coil output instruction writes a value for an output bit. If the output bit you specify uses
memory identifier Q, then the CPU turns the output bit in the process-image register on or
off, setting the specified bit equal to power flow status. The output signals for your control
actuators are wired to the Q terminals of the CPU. In RUN mode, the CPU system
continuously scans your input signals, processes the input states according to your program
logic, and then reacts by setting new output state values in the process-image output
register. After each program execution cycle, the CPU system transfers the new output state
reaction stored in the process-image register to the wired output terminals.
Table 7- 6
LAD

Output coil (LAD) and output assignment box (FBD)
FBD

Description
In FBD programming, LAD coils are transformed into assignment (= and /=) boxes
where you specify a bit address for the box output. Box inputs and outputs can be
connected to other box logic or you can enter a bit address.
You can specify an immediate write of a physical output using ":P" following the Q
offset (example: "%Q3.4:P"). For an immediate write, the bit data values are written
to the process image output and directly to physical output.

Table 7- 7

Data types for the parameters

Parameter

Data type

Description

OUT

Bool

Assigned bit

● If there is power flow through an output coil or an FBD "=" box is enabled, then the output
bit is set to 1.
● If there is no power flow through an output coil or an FBD "=" assignment box is not
enabled, then the output bit is set to 0.
● If there is power flow through an inverted output coil or an FBD "/=" box is enabled, then
the output bit is set to 0.
● If there is no power flow through an inverted output coil or an FBD "/=" box is not enabled,
then the output bit is set to 1.

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7.1 Bit logic

7.1.2

Set and reset instructions

Set and Reset 1 bit
Table 7- 8
LAD

S and R instructions
FBD

Description
When S (Set) is activated, then the data value at the OUT address is set to 1.
When S is not activated, OUT is not changed.
When R (Reset) is activated, then the data value at the OUT address is set to 0.
When R is not activated, OUT is not changed.

For LAD and FBD: These instructions can be placed anywhere in the network.

Table 7- 9

Data types for the parameters

Parameter

Data type

Description

IN (or connect to contact/gate logic)

Bool

Bit location to be monitored

OUT

Bool

Bit location to be set or reset

Set and Reset Bit Field
Table 7- 10
LAD1

SET_BF and RESET_BF instructions
FBD

Description
When SET_BF is activated, a data value of 1 is assigned to "n" bits starting at
address OUT. When SET_BF is not activated, OUT is not changed.

RESET_BF writes a data value of 0 to "n" bits starting at address OUT. When
RESET_BF is not activated, OUT is not changed.

For LAD and FBD: These instructions must be the right-most instruction in a branch.

Table 7- 11

Data types for the parameters

Parameter

Data type

Description

OUT

Bool

Starting element of a bit field to be set or reset (Example:
#MyArray[3])

Constant (UInt)

Number of bits to write

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7.1 Bit logic

Set-dominant and Reset-dominant bit latches
Table 7- 12
LAD / FBD

RS and SR instructions
Description
RS is a set dominant latch where the set dominates. If the set (S1) and reset (R) signals are both true,
the output address OUT will be 1.

SR is a reset dominant latch where the reset dominates. If the set (S) and reset (R1) signals are both
true, the output address OUT will be 0.

For LAD and FBD: These instructions must be the right-most instruction in a branch.

Table 7- 13

Data types for the parameters

Parameter

Data type

Description

S, S1

Bool

Set input; 1 indicates dominance

R, R1

Bool

Reset input; 1 indicates dominance

OUT

Bool

Assigned bit output "OUT"

Bool

Follows state of "OUT" bit

The OUT parameter specifies the bit address that is set or reset. The optional OUT output Q
reflects the signal state of the "OUT" address.
Instruction
RS

"OUT" bit

Previous state

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7.1 Bit logic

7.1.3
Table 7- 14
LAD

Positive and negative edge instructions
Positive and negative transition detection
FBD

Description
LAD: The state of this contact is TRUE when a positive transition (OFF-to-ON) is
detected on the assigned "IN" bit. The contact logic state is then combined with the
power flow in state to set the power flow out state. The P contact can be located
anywhere in the network except the end of a branch.
FBD: The output logic state is TRUE when a positive transition (OFF-to-ON) is
detected on the assigned input bit. The P box can only be located at the beginning
of a branch.
LAD: The state of this contact is TRUE when a negative transition (ON-to-OFF) is
detected on the assigned input bit. The contact logic state is then combined with
the power flow in state to set the power flow out state. The N contact can be
located anywhere in the network except the end of a branch.
FBD: The output logic state is TRUE when a negative transition (ON-to-OFF) is
detected on the assigned input bit. The N box can only be located at the beginning
of a branch.
LAD: The assigned bit "OUT" is TRUE when a positive transition (OFF-to-ON) is
detected on the power flow entering the coil. The power flow in state always
passes through the coil as the power flow out state. The P coil can be located
anywhere in the network.
FBD: The assigned bit "OUT" is TRUE when a positive transition (OFF-to-ON) is
detected on the logic state at the box input connection or on the input bit
assignment if the box is located at the start of a branch. The input logic state
always passes through the box as the output logic state. The P= box can be
located anywhere in the branch.
LAD: The assigned bit "OUT" is TRUE when a negative transition (ON-to-OFF) is
detected on the power flow entering the coil. The power flow in state always
passes through the coil as the power flow out state. The N coil can be located
anywhere in the network.
FBD: The assigned bit "OUT" is TRUE when a negative transition (ON-to-OFF) is
detected on the logic state at the box input connection or on the input bit
assignment if the box is located at the start of a branch. The input logic state
always passes through the box as the output logic state. The N= box can be
located anywhere in the branch.

Table 7- 15
LAD / FBD

P_TRIG and N_TRIG instructions
Description
The Q output power flow or logic state is TRUE when a positive transition (OFF-to-ON) is detected
on the CLK input state (FBD) or CLK power flow in (LAD).
In LAD, the P_TRIG instruction cannot be located at the beginning or end of a network. In FBD, the
P_TRIG instruction can be located anywhere except the end of a branch.
The Q output power flow or logic state is TRUE when a negative transition (ON-to-OFF) is detected
on the CLK input state (FBD) or CLK power flow in (LAD).
In LAD, the N_TRIG instruction cannot be located at the beginning or end of a network. In FBD, the
N_TRIG instruction can be located anywhere except the end of a branch.

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7.2 Timers
Table 7- 16

Data types for the parameters (P and N contacts/coils, P=, N=, P_TRIG and N_TRIG)

Parameter

Data type

Description

M_BIT

Bool

Memory bit in which the previous state of the input is saved

Bool

Input bit whose transition edge is to be detected

OUT

Bool

Output bit which indicates a transition edge was detected

CLK

Bool

Power flow or input bit whose transition edge is to be detected

Bool

Output which indicates an edge was detected

All edge instructions use a memory bit (M_BIT) to store the previous state of the input signal
being monitored. An edge is detected by comparing the state of the input with the state of
the memory bit. If the states indicate a change of the input in the direction of interest, then an
edge is reported by writing the output TRUE. Otherwise, the output is written FALSE.
Note
Edge instructions evaluate the input and memory-bit values each time they are executed,
including the first execution. You must account for the initial states of the input and memory
bit in your program design either to allow or to avoid edge detection on the first scan.
Because the memory bit must be maintained from one execution to the next, you should use
a unique bit for each edge instruction, and you should not use this bit any other place in your
program. You should also avoid temporary memory and memory that can be affected by
other system functions, such as an I/O update. Use only M, global DB, or Static memory (in
an instance DB) for M_BIT memory assignments.

7.2

Timers
You use the timer instructions to create programmed time delays. The number of timers that
you can use in your user program is limited only by the amount of memory in the CPU. Each
timer uses a 16 byte IEC_Timer data type DB structure to store timer data that is specified at
the top of the box or coil instruction. STEP 7 automatically creates the DB when you insert
the instruction.

Table 7- 17

Timer instructions

LAD / FBD boxes

LAD coils

Description
The TP timer generates a pulse with a preset width time.

The TON timer sets output Q to ON after a preset time delay.

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7.2 Timers

LAD / FBD boxes

LAD coils

Description
The TOF timer resets output Q to OFF after a preset time delay.

The TONR timer sets output Q to ON after a preset time delay. Elapsed time is
accumulated over multiple timing periods until the R input is used to reset the elapsed
time.

FBD only:

The PT (Preset timer) coil loads a new PRESET time value in the specified IEC_Timer.

FBD only:

The RT (Reset timer) coil resets the specified IEC_Timer.

STEP 7 automatically creates the DB when you insert the instruction.

Table 7- 18

Data types for the parameters

Parameter

Data type

Description

Box: IN
Coil: Power flow

Bool

TP, TON, and TONR:
Box: 0=Disable timer, 1=Enable timer
Coil: No power flow=Disable timer, Power flow=Enable timer
TOF:
Box: 0=Enable timer, 1=Disable timer
Coil: No power flow=Enable timer, Power flow=Disable timer

Bool

TONR box only:
0=No reset
1= Reset elapsed time and Q bit to 0

Box: PT
Coil: "PRESET_Tag"

Time

Timer box or coil: Preset time input

Box: Q
Coil: DBdata.Q

Bool

Timer box or coil: Timeout output
For timer coils, you must address the Q bit in the timer DB data.

Box: ET
Coil: DBdata.ELAPSED

Time

Timer box or coil: Elapsed time output
For timer coils, you must address the ELAPSED value in the timer DB data.

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7.2 Timers
Table 7- 19

Effect of value changes in the PT and IN parameters

Timer

Changes in the PT and IN box parameters and the corresponding coil parameters



Changing PT has no effect while the timer runs.



Changing IN has no effect while the timer runs.



Changing PT has no effect while the timer runs.



Changing IN to FALSE, while the timer runs, resets and stops the timer.



Changing PT has no effect while the timer runs.



Changing IN to TRUE, while the timer runs, resets and stops the timer.



Changing PT has no effect while the timer runs, but has an effect when the timer resumes.



Changing IN to FALSE, while the timer runs, stops the timer but does not reset the timer. Changing
IN back to TRUE will cause the timer to start timing from the accumulated time value.

TON
TOF
TONR

PT (preset time) and ET (elapsed time) values are stored in the specified IEC_TIMER DB
data as signed double integers that represent milliseconds of time. TIME data uses the T#
identifier and can be entered as a simple time unit (T#200ms or 200) and as compound time
units like T#2s_200ms.
Table 7- 20
Data type
TIME
1

Size and range of the TIME data type
Size
32 bits, stored
as DInt data

Valid number ranges1
T#-24d_20h_31m_23s_648ms to T#24d_20h_31m_23s_647ms
Stored as -2,147,483,648 ms to +2,147,483,647 ms

The negative range of the TIME data type shown above cannot be used with the timer instructions. Negative PT (preset
time) values are set to zero when the timer instruction is executed. ET (elapsed time) is always a positive value.

Timer coil example
The -(TP)-, -(TON)-, -(TOF)-, and -(TONR)- timer coils must be the last instruction in a LAD
network. As shown in the timer example, a contact instruction in a subsequent network
evaluates the Q bit in a timer coil's IEC_Timer DB data. Likewise, you must address the
ELAPSED element in the IEC_timer DB data if you want to use the elapsed time value in
your program.

The pulse timer is started on a 0 to 1 transition of the Tag_Input bit value. The timer runs for
the time specified by Tag_Time time value.

As long as the timer runs, the state of DB1.MyIEC_Timer.Q=1 and the Tag_Output value=1.
When the Tag_Time value has elapsed, then DB1.MyIEC_Timer.Q=0 and the Tag_Output
value=0.

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7.2 Timers

Reset timer -(RT)- and Preset timer -(PT)- coils
These coil instructions can be used with box or coil timers and can be placed in a mid-line
position. The coil output power flow status is always the same as the coil input status. When
the -(RT)- coil is activated, the ELAPSED time element of the specified IEC_Timer DB data
is reset to 0. When the -(PT)- coil is activated, the PRESET time element of the specified
IEC_Timer DB data is reset to 0.
Note
When you place timer instructions in an FB, you can select the "Multi-instance data block"
option. The timer structure names can be different with separate data structures, but the
timer data is contained in a single data block and does not require a separate data block for
each timer. This reduces the processing time and data storage necessary for handling the
timers. There is no interaction between the timer data structures in the shared multi-instance
DB.

Operation of the timers
Table 7- 21

Types of IEC timers

Timer

Timing diagram

TP: Pulse timer

The TP timer generates a pulse with a preset width
time.

(7
37

4
37

TON: ON-delay timer
The TON timer sets output Q to ON after a preset time
delay.

(7
37

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7.2 Timers

Timer

Timing diagram

TOF: OFF-delay timer

The TOF timer resets output Q to OFF after a preset
time delay.

(7
37

TONR: ON-delay Retentive timer
The TONR timer sets output Q to ON after a preset time
delay. Elapsed time is accumulated over multiple timing
periods until the R input is used to reset the elapsed
time.

Note
In the CPU, no dedicated resource is allocated to any specific timer instruction. Instead,
each timer utilizes its own timer structure in DB memory and a continuously-running internal
CPU timer to perform timing.
When a timer is started due to an edge change on the input of a TP, TON, TOF, or TONR
instruction, the value of the continuously-running internal CPU timer is copied into the
START member of the DB structure allocated for this timer instruction. This start value
remains unchanged while the timer continues to run, and is used later each time the timer is
updated. Each time the timer is started, a new start value is loaded into the timer structure
from the internal CPU timer.
When a timer is updated, the start value described above is subtracted from the current
value of the internal CPU timer to determine the elapsed time. The elapsed time is then
compared with the preset to determine the state of the timer Q bit. The ELAPSED and Q
members are then updated in the DB structure allocated for this timer. Note that the elapsed
time is clamped at the preset value (the timer does not continue to accumulate elapsed time
after the preset is reached).

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7.2 Timers
A timer update is performed when and only when:
● A timer instruction (TP, TON, TOF, or TONR) is executed
● The "ELAPSED" member of the timer structure in DB is referenced directly by an
instruction
● The "Q" member of the timer structure in DB is referenced directly by an instruction

Timer programming
The following consequences of timer operation should be considered when planning and
creating your user program:
● You can have multiple updates of a timer in the same scan. The timer is updated each
time the timer instruction (TP, TON, TOF, TONR) is executed and each time the
ELAPSED or Q member of the timer structure is used as a parameter of another
executed instruction. This is an advantage if you want the latest time data (essentially an
immediate read of the timer). However, if you desire to have consistent values throughout
a program scan, then place your timer instruction prior to all other instructions that need
these values, and use tags from the Q and ET outputs of the timer instruction instead of
the ELAPSED and Q members of the timer DB structure.
● You can have scans during which no update of a timer occurs. It is possible to start your
timer in a function, and then cease to call that function again for one or more scans. If no
other instructions are executed which reference the ELAPSED or Q members of the timer
structure, then the timer will not be updated. A new update will not occur until either the
timer instruction is executed again or some other instruction is executed using ELAPSED
or Q from the timer structure as a parameter.
● Although not typical, you can assign the same DB timer structure to multiple timer
instructions. In general, to avoid unexpected interaction, you should only use one timer
instruction (TP, TON, TOF, TONR) per DB timer structure.
● Self-resetting timers are useful to trigger actions that need to occur periodically. Typically,
self-resetting timers are created by placing a normally-closed contact which references
the timer bit in front of the timer instruction. This timer network is typically located above
one or more dependent networks that use the timer bit to trigger actions. When the timer
expires (elapsed time reaches preset value), the timer bit is ON for one scan, allowing the
dependent network logic controlled by the timer bit to execute. Upon the next execution of
the timer network, the normally closed contact is OFF, thus resetting the timer and
clearing the timer bit. The next scan, the normally closed contact is ON, thus restarting
the timer. When creating self-resetting timers such as this, do not use the "Q" member of
the timer DB structure as the parameter for the normally-closed contact in front of the
timer instruction. Instead, use the tag connected to the "Q" output of the timer instruction
for this purpose. The reason to avoid accessing the Q member of the timer DB structure
is because this causes an update to the timer and if the timer is updated due to the
normally closed contact, then the contact will reset the timer instruction immediately. The
Q output of the timer instruction will not be ON for the one scan and the dependent
networks will not execute.

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7.2 Timers

Time data retention after a RUN-STOP-RUN transition or a CPU power cycle
If a run mode session is ended with stop mode or a CPU power cycle and a new run mode
session is started, then the timer data stored in the previous run mode session is lost, unless
the timer data structure is specified as retentive (TP, TON, TOF, and TONR timers).
When you accept the defaults in the call options dialog after you place a timer instruction in
the program editor, you are automatically assigned an instance DB which cannot be made
retentive. To make your timer data retentive, you must either use a global DB or a Multiinstance DB.

Assign a global DB to store timer data as retentive data
This option works regardless of where the timer is placed (OB, FC, or FB).
1. Create a global DB:
– Double-click "Add new block" from the Project tree
– Click the data block (DB) icon
– For the Type, choose global DB
– If you want to be able to select individual data elements in this DB as retentive, be
sure the DB type "Optimized" box is checked. The other DB type option "Standard compatible with S7-300/400" only allows setting all DB data elements retentive or
none retentive.
– Click OK
2. Add timer structure(s) to the DB:
– In the new global DB, add a new static tag using data type IEC_Timer.
– In the "Retain" column, check the box so that this structure will be retentive.
– Repeat this process to create structures for all the timers that you want to store in this
DB. You can either place each timer structure in a unique global DB, or you can place
multiple timer structures into the same global DB. You can also place other static tags
besides timers in this global DB. Placing multiple timer structures into the same global
DB allows you to reduce your overall number of blocks.
– Rename the timer structures if desired.
3. Open the program block for editing where you want to place a retentive timer (OB, FC, or
FB).
4. Place the timer instruction at the desired location.
5. When the call options dialog appears, click the cancel button.
6. On the top of the new timer instruction, type the name (do not use the helper to browse)
of the global DB and timer structure that you created above (example:
"Data_block_3.Static_1").

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7.2 Timers

Assign a multi-instance DB to store timer data as retentive data
This option only works if you place the timer in an FB.
This option depends upon whether the FB was created with "Optimized" block access
(allows symbolic access only). Once the FB has been created, you cannot change the
checkbox for "Optimized"; it must be chosen correctly when the FB is created, on the first
screen after selecting "Add new block" from the tree. To verify how the access attribute is
configured for an existing FB, right-click on the FB in the Project tree, choose properties, and
then choose attributes.
If the FB was created with the "Optimized" box checked (allows symbolic access only):
1. Open the FB for edit.
2. Place the timer instruction at the desired location in the FB.
3. When the Call options dialog appears, click on the Multi instance icon. The Multi Instance
option is only available if the instruction is being placed into an FB.
4. In the Call options dialog, rename the timer if desired.
5. Click OK. The timer instruction appears in the editor, and the IEC_TIMER structure
appears in the FB Interface under Static.
6. If necessary, open the FB interface editor (may have to click on the small arrow to
expand the view).
7. Under Static, locate the timer structure that was just created for you.
8. In the Retain column for this timer structure, change the selection to "Retain". Whenever
this FB is called later from another program block, an instance DB will be created with this
interface definition which contains the timer structure marked as retentive.
If the FB was created with the "Standard - compatible with S7-300/400" box checked (allows
symbolic and direct access):
1. Open the FB for edit.
2. Place the timer instruction at the desired location in the FB.
3. When the Call options dialog appears, click on the multi instance icon. The multi instance
option is only available if the instruction is being placed into an FB.
4. In the Call options dialog, rename the timer if desired.
5. Click OK. The timer instruction appears in the editor, and the IEC_TIMER structure
appears in the FB Interface under Static.
6. Open the block that will use this FB.
7. Place this FB at the desired location. Doing so results in the creation of an instance data
block for this FB.
8. Open the instance data block created when you placed the FB in the editor.
9. Under Static, locate the timer structure of interest. In the Retain column for this timer
structure, check the box to make this structure retentive.

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7.3 Counters

7.3
Table 7- 22

Counters
Counter instructions

LAD / FBD

Description
Use the counter instructions to count internal program events and external process events. Each
counter uses a structure stored in a data block to maintain counter data. You assign the data block
when the counter instruction is placed in the editor.


CTU is a count-up counter



CTD is a count-down counter



CTUD is a count-up-and-down counter

For LAD and FBD: Select the count value data type from the drop-down list below the instruction name.

STEP 7 automatically creates the DB when you insert the instruction.

Table 7- 23

Data types for the parameters

Parameter

Data type1

Description

CU, CD

Bool

Count up or count down, by one count

R (CTU, CTUD)

Bool

Reset count value to zero

LOAD (CTD, CTUD)

Bool

Load control for preset value

SInt, Int, DInt, USInt, UInt, UDInt

Preset count value

Q, QU

Bool

True if CV >= PV

Bool

True if CV <= 0

SInt, Int, DInt, USInt, UInt, UDInt

Current count value

The numerical range of count values depends on the data type you select. If the count value is an unsigned integer
type, you can count down to zero or count up to the range limit. If the count value is a signed integer, you can count
down to the negative integer limit and count up to the positive integer limit.

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7.3 Counters
The number of counters that you can use in your user program is limited only by the amount
of memory in the CPU. Counters use the following amount of memory:
● For SInt or USInt data types, the counter instruction uses 3 bytes.
● For Int or UInt data types, the counter instruction uses 6 bytes.
● For DInt or UDInt data types, the counter instruction uses 12 bytes.
These instructions use software counters whose maximum counting rate is limited by the
execution rate of the OB in which they are placed. The OB that the instructions are placed in
must be executed often enough to detect all transitions of the CU or CD inputs. For faster
counting operations, see the CTRL_HSC instruction (Page 287).
Note
When you place counter instructions in an FB, you can select the multi-instance DB option,
the counter structure names can be different with separate data structures, but the counter
data is contained in a single DB and does not require a separate DB for each counter. This
reduces the processing time and data storage necessary for the counters. There is no
interaction between the counter data structures in the shared multi-instance DB.

Operation of the counters
Table 7- 24

Operation of the CTU counter

Counter
The CTU counter counts up by 1 when the value of parameter CU
changes from 0 to 1. The CTU timing diagram shows the operation for
an unsigned integer count value (where PV = 3).




If the value of parameter CV (current count value) is greater than or
equal to the value of parameter PV (preset count value), then the
counter output parameter Q = 1.
If the value of the reset parameter R changes from 0 to 1, then the
current count value is reset to 0.

Operation
&8
5

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7.3 Counters
Table 7- 25

Operation of the CTD counter

Counter

Operation

The CTD counter counts down by 1 when the value of
parameter CD changes from 0 to 1. The CTD timing diagram
shows the operation for an unsigned integer count value
(where PV = 3).



If the value of parameter LOAD changes from 0 to 1, the
value at parameter PV (preset value) is loaded to the
counter as the new CV (current count value).

Operation of the CTUD counter

Counter
The CTUD counter counts up or
down by 1 on the 0 to 1
transition of the count up (CU) or
count down (CD) inputs. The
CTUD timing diagram shows the
operation for an unsigned
integer count value (where PV =
4).



/2$'

If the value of parameter CV (current count value) is equal
to or less than 0, the counter output parameter Q = 1.

Table 7- 26



Operation
&8
&'

If the value of parameter CV /2$'
is equal to or greater than the
value of parameter PV, then
the counter output parameter
QU = 1.
If the value of parameter CV
is less than or equal to zero,
then the counter output
parameter QD = 1.



If the value of parameter
LOAD changes from 0 to 1,
then the value at parameter
PV is loaded to the counter
as the new CV.



If the value of the reset
parameter R is changes from
0 to 1, the current count
value is reset to 0.

48
4'

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7.3 Counters

Counter data retention after a RUN-STOP-RUN transition or a CPU power cycle
If a run mode session is ended with stop mode or a CPU power cycle and a new run mode
session is started, then the counter data stored in the previous run mode session is lost,
unless the counter data structure is specified as retentive (CTU, CTD, and CTUD counters).
When you accept the defaults in the call options dialog after you place a counter instruction
in the program editor, you are automatically assigned an instance DB which cannot be made
retentive. To make your counter data retentive, you must either use a global DB or a Multiinstance DB.

Assign a global DB to store timer data as retentive data
This option works regardless of where the counter is placed (OB, FC, or FB).
1. Create a global DB:
– Double-click "Add new block" from the Project tree
– Click the data block (DB) icon
– For the Type, choose global DB
– If you want to be able to select individual items in this DB as retentive, be sure the
symbolic-access-only box is checked.
– Click OK
2. Add counter structure(s) to the DB:
– In the new global DB, add a new static tag using one of the counter data types. Be
sure to consider the Type you want to use for your Preset and Count values.
Counter Data Type

Corresponding Type for the Preset and Count Values

IEC_Counter

INT

IEC_SCounter

SINT

IEC_DCounter

DINT

IEC_UCounter

UINT

IEC_USCounter

USINT

IEC_UDCounter

UDINT

1. In the "Retain" column, check the box so that this structure will be retentive.
– Repeat this process to create structures for all the counters that you want to store in
this DB. You can either place each counter structure in a unique global DB, or you can
place multiple counter structures into the same global DB. You can also place other
static tags besides counters in this global DB. Placing multiple counter structures into
the same global DB allows you to reduce your overall number of blocks.
– Rename the counter structures if desired.
2. Open the program block for editing where you want to place a retentive counter (OB, FC,
or FB).
3. Place the counter instruction at the desired location.

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7.3 Counters
4. When the call options dialog appears, click the cancel button. You should now see a new
counter instruction which has "???" both just above and just below the instruction name.
5. On the top of the new counter instruction, type the name (do not use the helper to
browse) of the global DB and counter structure that you created above (example:
"Data_block_3.Static_1"). This causes the corresponding preset and count value type to
be filled in (example: UInt for an IEC_UCounter structure).

Assign a multi-instance DB to store counter data as retentive data
This option only works if you place the counter in an FB.
This option depends upon whether the FB was created as symbolic access only. Once the
FB has been created, you cannot change the checkbox for "Symbolic access only"; it must
be chosen correctly when the FB is created, on the first screen after selecting "Add new
block" from the tree. To see how this box is configured for an existing FB, right-click on the
FB in the Project tree, choose properties, and then choose attributes.
If the FB was created with the "Symbolic access only" box checked:
1. Open the FB for edit.
2. Place the counter instruction at the desired location in the FB.
3. When the Call options dialog appears, click on the Multi instance icon. The Multi Instance
option is only available if the instruction is being placed into an FB.
4. In the Call options dialog, rename the counter if desired.
5. Click OK. The counter instruction appears in the editor with type INT for the preset and
count values, and the IEC_COUNTER structure appears in the FB Interface under Static.
6. If desired, change the type in the counter instruction from INT to one of the other types.
The counter structure will change correspondingly.
Type shown in counter instruction (for preset Corresponding structure Type shown in FB
and count values)
interface
INT

IEC_Counter

SINT

IEC_SCounter

DINT

IEC_DCounter

UINT

IEC_UCounter

USINT

IEC_USCounter

UDINT

IEC_UDCounter

1. If necessary, open the FB interface editor (may have to click on the small arrow to
expand the view).
2. Under Static, locate the counter structure that was just created for you.
3. In the Retain column for this counter structure, change the selection to "Retain".
Whenever this FB is called later from another program block, an instance DB will be
created with this interface definition which contains the counter structure marked as
retentive.

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7.3 Counters
If the FB was created with the "Symbolic access only" box not checked:
1. Open the FB for edit.
2. Place the counter instruction at the desired location in the FB.
3. When the Call options dialog appears, click on the multi instance icon. The multi instance
option is only available if the instruction is being placed into an FB.
4. In the Call options dialog, rename the counter if desired.
5. Click OK. The counter instruction appears in the editor with type INT for the preset and
count value, and the IEC_COUNTER structure appears in the FB Interface under Static.
6. If desired, change the type in the counter instruction from INT to one of the other types.
The counter structure will change correspondingly.
Type shown in counter instruction (for preset Corresponding structure Type shown in FB
and count values)
interface
INT

IEC_Counter

SINT

IEC_SCounter

DINT

IEC_DCounter

UINT

IEC_UCounter

USINT

IEC_USCounter

UDINT

IEC_UDCounter

1. Open the block that will use this FB.
2. Place this FB at the desired location. Doing so results in the creation of an instance data
block for this FB.
3. Open the instance data block created when you placed the FB in the editor.
4. Under Static, locate the counter structure of interest. In the Retain column for this counter
structure, check the box to make this structure retentive.

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7.4 Compare

7.4

Compare

7.4.1

Compare

Table 7- 27

Compare instructions

LAD

FBD

Description
Compares two values of the same data type. When the LAD contact comparison is
TRUE, then the contact is activated. When the FBD box comparison is TRUE, then
the box output is TRUE.

For LAD and FBD: Click the instruction name (such as "==") to change the comparison type from the drop-down list.
Click the "???" and select data type from the drop-down list.

Table 7- 28

Data types for the parameters

Parameter

Data type

Description

IN1, IN2

SInt, Int, DInt, USInt, UInt, UDInt, Real, LReal, String, Char,
Time, DTL, Constant

Values to compare

Table 7- 29

Comparison descriptions

Relation type

The comparison is true if ...

IN1 is equal to IN2

IN1 is not equal to IN2

IN1 is greater than or equal to IN2

IN1 is less than or equal to IN2

IN1 is greater than IN2

IN1 is less than IN2

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7.4.2
Table 7- 30

In-range and Out-of-range instructions
In Range and Out of Range instructions

LAD / FBD

Description
Tests whether an input value is in or out of a specified value range.
If the comparison is TRUE, then the box output is TRUE.

For LAD and FBD: Click the "???" and select the data type from the drop-down list.

Table 7- 31

Data types for the parameters

Parameter

Data type1

Description

MIN, VAL, MAX

SInt, Int, DInt, USInt, UInt, UDInt, Real, LReal, Constant

Comparator inputs

The input parameters MIN, VAL, and MAX must be the same data type.

● The IN_RANGE comparison is true if: MIN <= VAL <= MAX
● The OUT_RANGE comparison is true if: VAL < MIN or VAL > MAX

7.4.3
Table 7- 32
LAD

OK and Not OK instructions
OK and Not OK instructions
FBD

Description
Tests whether an input data reference is a valid real number according to IEEE
specification 754.

For LAD and FBD: When the LAD contact is TRUE, the contact is activated and passes power flow. When the FBD box
is TRUE, then the box output is TRUE.

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7.5 Math
Table 7- 33
Parameter

Data type

Description

Real, LReal

Input data

Table 7- 34

Data types for the parameter

Operation

Instruction

The Real number test is TRUE if:

The input value is a valid real number 1

NOT_OK

The input value is not a valid real number 1

A Real or LReal value is invalid if it is +/- INF (infinity), NaN (Not a Number), or if it is a denormalized value. A
denormalized value is a number very close to zero. The CPU substitutes a zero for a denormalized value in calculations.

7.5

Math

7.5.1

Calculate instruction

Table 7- 35

CALCULATE instruction

LAD / FBD

Description
The CALCULATE instruction lets you create a math function that operates on inputs (IN1,
IN2, .. INn) and produces the result at OUT, according to the equation that you define.

Table 7- 36



Select a data type first. All inputs and the output must be the same data type.



To add another input, click the icon at the last input.

Data types for the parameters

Parameter

Data type1

IN1, IN2, ..INn

SInt, Int, DInt, USInt, UInt, UDInt, Real, LReal, Byte, Word, DWord

OUT

SInt, Int, DInt, USInt, UInt, UDInt, Real, LReal, Byte, Word, DWord

The IN and OUT parameters must be the same data type (with implicit conversions of the input parameters). For
example: A SINT value for an input would be converted to an INT or a REAL value if OUT is an INT or REAL

Click the calculator icon to open the dialog and define your math function. You enter your
equation as inputs (such as IN1 and IN2) and operations. When you click "OK" to save the
function, the dialog automatically creates the inputs for the CALCULATE instruction.
An example and a list of possible math operations you can include is shown at the bottom of
the editor.

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7.5 Math

Note
You also must create an input for any constants in your function. The constant value would
then be entered in the associated input for the CALCULATE instruction.
By entering constants as inputs, you can copy the CALCULATE instruction to other locations
in your user program without having to change the function. You then can change the values
or tags of the inputs for the instruction without modifying the function.
When CALCULATE is executed and all the individual operations in the calculation complete
successfully, then the ENO = 1. Otherwise, ENO = 0.

7.5.2
Table 7- 37
LAD / FBD

Add, subtract, multiply and divide instructions
Add, subtract, multiply and divide instructions
Description


ADD: Addition (IN1 + IN2 = OUT)



SUB: Subtraction (IN1 - IN2 = OUT)



MUL: Multiplication (IN1 * IN2 = OUT)

 DIV: Division (IN1 / IN2 = OUT)
An Integer division operation truncates the fractional part of the quotient to produce an integer output.
1

For LAD and FBD: Click the "???" and select a data type from the drop-down menu.

Table 7- 38
Parameter

Data types for the parameters (LAD and FBD)
Data type1

Description

IN1, IN2

SInt, Int, DInt, USInt, UInt, UDInt, Real, LReal, Constant

Math operation inputs

OUT

SInt, Int, DInt, USInt, UInt, UDInt, Real, LReal

Math operation output

Parameters IN1, IN2, and OUT must be the same data type.

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To add an ADD or MUL input, click the "Create" icon or right-click on an input
stub for one of the existing IN parameters and select the "Insert input" command.
To remove an input, right-click on an input stub for one of the existing IN parameters (when
there are more than the original two inputs) and select the "Delete" command.
When enabled (EN = 1), the math instruction performs the specified operation on the input
values (IN1 and IN2) and stores the result in the memory address specified by the output
parameter (OUT). After the successful completion of the operation, the instruction sets ENO
= 1.
Table 7- 39

ENO status

ENO

Description

No error

The Math operation result value would be outside the valid number range of the data type selected. The
least significant part of the result that fits in the destination size is returned.

Division by 0 (IN2 = 0): The result is undefined and zero is returned.

Real/LReal: If one of the input values is NaN (not a number) then NaN is returned.

ADD Real/LReal: If both IN values are INF with different signs, this is an illegal operation and NaN is
returned.

SUB Real/LReal: If both IN values are INF with the same sign, this is an illegal operation and NaN is
returned.

MUL Real/LReal: If one IN value is zero and the other is INF, this is an illegal operation and NaN is
returned.

DIV Real/LReal: If both IN values are zero or INF, this is an illegal operation and NaN is returned.

7.5.3

Modulo instruction

Table 7- 40

MOD instruction

LAD / FBD

Description
You can use the MOD instruction to return the remainder of an integer division operation. The value at
the IN1 input is divided by the value at the IN2 input and the remainder is returned at the OUT output.

For LAD and FBD: Click the "???" and select a data type from the drop-down menu.

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7.5 Math
Table 7- 41
Parameter

Data types for parameters
Data type1

Description

IN1 and IN2

SInt, Int, DInt, USInt, UInt, UDInt, Constant

Modulo inputs

OUT

SInt, Int, DInt, USInt, UInt, UDInt

Modulo output

The IN1, IN2, and OUTparameters must be the same data type.

Table 7- 42
ENO

ENO values
Description

No error

Value IN2 = 0, OUT is assigned the value zero

7.5.4
Table 7- 43
LAD / FBD

Negation instruction
NEG instruction
Description
The NEG instruction inverts the arithmetic sign of the value at parameter IN and stores the result in
parameter OUT.

For LAD and FBD: Click the "???" and select a data type from the drop-down menu.

Table 7- 44

Data types for parameters

Parameter

Data type1

Description

SInt, Int, DInt, Real, LReal, Constant

Math operation input

OUT

SInt, Int, DInt, Real, LReal

Math operation output

The IN and OUT parameters must be the same data type.

Table 7- 45

ENO status

ENO

Description

No error

The resulting value is outside the valid number range of the selected data type.
Example for SInt: NEG (-128) results in +128 which exceeds the data type maximum.

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7.5 Math

7.5.5
Table 7- 46
LAD / FBD

Increment and decrement instructions
INC and DEC instructions
Description
Increments a signed or unsigned integer number value:
IN_OUT value +1 = IN_OUT value

Decrements a signed or unsigned integer number value:
IN_OUT value - 1 = IN_OUT value

For LAD and FBD: Click the "???" and select a data type from the drop-down menu.

Table 7- 47

Data types for parameters

Parameter

Data type

Description

IN/OUT

SInt, Int, DInt, USInt, UInt, UDInt

Math operation input and output

Table 7- 48

ENO status

ENO

Description

No error

The resulting value is outside the valid number range of the selected data type.
Example for SInt: INC (+127) results in +128, which exceeds the data type maximum.

7.5.6
Table 7- 49
LAD / FBD

Absolute value instruction
ABS instruction
Description
Calculates the absolute value of a signed integer or real number at parameter IN and stores the result in
parameter OUT.

For LAD and FBD: Click the "???" and select a data type from the drop-down menu.

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7.5 Math
Table 7- 50

Data types for parameters
Data type1

Description

SInt, Int, DInt, Real, LReal

Math operation input

OUT

SInt, Int, DInt, Real, LReal

Math operation output

Parameter

The IN and OUT parameters must be the same data type.

Table 7- 51

ENO status

ENO

Description

No error

The math operation result value is outside the valid number range of the selected data type.
Example for SInt: ABS (-128) results in +128 which exceeds the data type maximum.

7.5.7

Minimum and Maximum instructions

Table 7- 52

MIN and MAX instructions

LAD / FBD

Description
The MIN instruction compares the value of two parameters IN1 and IN2 and assigns the minimum
(lesser) value to parameter OUT.

The MAX instruction compares the value of two parameters IN1 and IN2 and assigns the maximum
(greater) value to parameter OUT.

For LAD and FBD: Click the "???" and select a data type from the drop-down menu.

Table 7- 53

Data types for the parameters

Parameter

Data type1

Description

IN1, IN2
[...IN32]

SInt, Int, DInt, USInt, UInt, UDInt, Real, LReal, Constant

Math operation inputs (up to 32 inputs)

OUT

SInt, Int, DInt, USInt, UInt, UDInt, Real, LReal

Math operation output

The IN1, IN2, and OUT parameters must be the same data type.

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To add an input, click the "Create" icon or right-click on an input stub for one of
the existing IN parameters and select the "Insert input" command.
To remove an input, right-click on an input stub for one of the existing IN parameters (when
there are more than the original two inputs) and select the "Delete" command.
Table 7- 54

ENO status

ENO

Description

No error

For Real data type only:

7.5.8



One or more inputs is not a real number (NaN).



The resulting OUT is +/- INF (infinity).

Limit instruction

Table 7- 55

LIMIT instruction

LAD / FBD

Description
The Limit instruction tests if the value of parameter IN is inside the value range specified by parameters
MIN and MAX and if not, clamps the value at MIN or MAX.

For LAD and FBD: Click the "???" and select a data type from the drop-down menu.

Table 7- 56

Data types for the parameters

Parameter

Data type1

Description

MIN, IN, and MAX

SInt, Int, DInt, USInt, UInt, UDInt, Real, LReal, Constant

Math operation inputs

OUT

SInt, Int, DInt, USInt, UInt, UDInt, Real, LReal

Math operation output

The MIN, IN, MAX, and OUT parameters must be the same data type.

If the value of parameter IN is within the specified range, then the value of IN is stored in
parameter OUT. If the value of parameter IN is outside of the specified range, then the OUT
value is the value of parameter MIN (if the IN value is less than the MIN value) or the value
of parameter MAX (if the IN value is greater than the MAX value).

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Table 7- 57

ENO status

ENO

Description

No error

Real: If one or more of the values for MIN, IN and MAX is NaN (Not a Number), then NaN is returned.

If MIN is greater than MAX, the value IN is assigned to OUT.

7.5.9

Floating-point math instructions
You use the floating point instructions to program mathematical operations using a Real or
LReal data type:
● SQR: Square (IN 2 = OUT)
● SQRT: Square root (√IN = OUT)
● LN: Natural logarithm (LN(IN) = OUT)
● EXP: Natural exponential (e IN =OUT), where base e = 2.71828182845904523536
● EXPT: General exponential (IN1 IN2 = OUT)
EXPT parameters IN1 and OUT are always the same data type, for which you must
select Real or LReal. You can select the data type for the exponent parameter IN2 from
among many data types.
● FRAC: Fraction (fractional part of floating point number IN = OUT)
● SIN: Sine (sin(IN radians) = OUT)
ASIN: Inverse sine (arcsine(IN) = OUT radians), where the sin(OUT radians) = IN
● COS: Cosine (cos(IN radians) = OUT)
ACOS: Inverse cosine (arccos(IN) = OUT radians), where the cos(OUT radians) = IN
● TAN: Tangent (tan(IN radians) = OUT)
ATAN: Inverse tangent (arctan(IN) = OUT radians), where the tan(OUT radians) = IN

Table 7- 58
LAD / FBD

Examples of floating-point math instructions
Description
Square: IN 2 = OUT
For example: If IN = 9, then OUT = 81.

General exponential: IN1 IN2 = OUT
For example: If IN1 = 3 and IN2 = 2, then OUT = 9.

For LAD and FBD: Click the "???" (by the instruction name) and select a data type from the drop-down menu.

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Table 7- 59

Data types for parameters

Parameter

Data type

Description

IN, IN1

Real, LReal, Constant

Inputs

IN2

SInt, Int, DInt, USInt, UInt,UDInt, Real, LReal, Constant

EXPT exponent input

OUT

Real, LReal

Outputs

Table 7- 60

ENO status

ENO

Instruction

Condition

Result (OUT)

All

No error

Valid result

SQR
SQRT
LN

Result exceeds valid Real/LReal range

+INF

IN is +/- NaN (not a number)

+NaN

IN is negative

-NaN

IN is +/- INF (infinity) or +/- NaN

+/- INF or +/- NaN

IN is 0.0, negative, -INF, or -NaN

-NaN

IN is +INF or +NaN

+INF or +NaN

EXP

Result exceeds valid Real/LReal range

+INF

IN is +/- NaN

+/- NaN

SIN, COS, TAN

IN is +/- INF or +/- NaN

+/- INF or +/- NaN

ASIN, ACOS

IN is outside valid range of -1.0 to +1.0

+NaN

IN is +/- NaN

+/- NaN

ATAN

IN is +/- NaN

+/- NaN

FRAC

IN is +/- INF or +/- NaN

+NaN

EXPT

IN1 is +INF and IN2 is not -INF

+INF

IN1 is negative or -INF

+NaN if IN2 is Real/LReal,
-INF otherwise

IN1 or IN2 is +/- NaN

+NaN

IN1 is 0.0 and IN2 is Real/LReal (only)

+NaN

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7.6 Move

7.6

Move

7.6.1

Move and block move instructions
Use the Move instructions to copy data elements to a new memory address and convert
from one data type to another. The source data is not changed by the move process.
● The MOVE instruction copies a single data element from the source address specified by
the IN parameter to the destination addresses specified by the OUT parameter.
● The MOVE_BLK and UMOVE_BLK instructions have an additional COUNT parameter.
The COUNT specifies how many data elements are copied. The number of bytes per
element copied depends on the data type assigned to the IN and OUT parameter tag
names in the PLC tag table.

Table 7- 61
LAD / FBD

MOVE, MOVE_BLK and UMOVE_BLK instructions
Description
Copies a data element stored at a specified address to a new address or multiple addresses.1

Interruptible move that copies a block of data elements to a new address.

Uninterruptible move that copies a block of data elements to a new address.

MOVE instruction: To add another output in LAD or FBD, click the "Create" icon by the output parameter.

Table 7- 62

Data types for the MOVE instruction

Parameter

Data type

Description

SInt, Int, DInt, USInt, UInt, UDInt, Real, LReal, Byte, Word,
DWord, Char, Array, Struct, DTL, Time

Source address

OUT

SInt, Int, DInt, USInt, UInt, UDInt, Real, LReal, Byte, Word,
DWord, Char, Array, Struct, DTL, Time

Destination address

To add MOVE outputs, click the "Create" icon or right-click on an output stub for
one of the existing OUT parameters and select the "Insert output" command.
To remove an output, right-click on an output stub for one of the existing OUT parameters
(when there are more than the original two outputs) and select the "Delete" command.

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Table 7- 63

Data types for the MOVE_BLK and UMOVE_BLK instructions

Parameter

Data type

Description

SInt, Int, DInt, USInt, UInt, UDInt, Real, LReal Byte,
Word, DWord

Source start address

COUNT

UInt

Number of data elements to copy

OUT

SInt, Int, DInt, USInt, UInt, UDInt, Real, LReal, Byte,
Word, DWord

Destination start address

Note
Rules for data copy operations
 To copy the Bool data type, use SET_BF, RESET_BF, R, S, or output coil (LAD)
(Page 150)
 To copy a single elementary data type, use MOVE
 To copy an array of an elementary data type, use MOVE_BLK or UMOVE_BLK
 To copy a structure, use MOVE
 To copy a string, use S_MOVE (Page 214)
 To copy a single character in a string, use MOVE
 The MOVE_BLK and UMOVE_BLK instructions cannot be used to copy arrays or
structures to the I, Q, or M memory areas.
MOVE_BLK and UMOVE_BLK instructions differ in how interrupts are handled:
● Interrupt events are queued and processed during MOVE_BLK execution. Use the
MOVE_BLK instruction when the data at the move destination address is not used within
an interrupt OB subprogram or, if used, the destination data does not have to be
consistent. If a MOVE_BLK operation is interrupted, then the last data element moved is
complete and consistent at the destination address. The MOVE_BLK operation is
resumed after the interrupt OB execution is complete.
● Interrupt events are queued but not processed until UMOVE_BLK execution is complete.
Use the UMOVE_BLK instruction when the move operation must be completed and the
destination data consistent, before the execution of an interrupt OB subprogram. For
more information, see the section on data consistency (Page 134).
ENO is always true following execution of the MOVE instruction.
Table 7- 64

ENO status

ENO

Condition

Result

No error

All COUNT elements were
successfully copied.

Either the source (IN) range or the destination
(OUT) range exceeds the available memory
area.

Elements that fit are copied. No partial
elements are copied.

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7.6 Move

7.6.2

FieldRead and FieldWrite instructions
Note
STEP 7 V10.5 did not support a variable reference as an array index or multi-dimensional
arrays. The FieldRead and FieldWrite instructions were used to provide variable array index
operations for a one-dimensional array. STEP 7 V11 does support a variable as an array
index and multi-dimensional arrays. FieldRead and FieldWrite are included in STEP 7 V11
for backward compatibility with programs that have used these instructions.

Table 7- 65

FieldRead and FieldWrite instructions

LAD / FBD

Description
FieldRead reads the array element with the index value INDEX from the array whose first
element in specified by the MEMBER parameter. The value of the array element is
transferred to the location specified at the VALUE parameter.

WriteField transfers the value at the location specified by the VALUE parameter to the array
whose first element is specified by the MEMBER parameter. The value is transferred to the
array element whose array index is specified by the INDEX parameter.

For LAD and FBD: Click the "???" and select a data type from the drop-down menu.

Table 7- 66

Data types for parameters

Parameter and type

Data type

Description

Index

Input

DInt

The index number of the array element to be
read or written to

Member 1

Input

Array element types:
Bool, Byte, Word, DWord, Char, SInt, Int,
Dint, USInt, UInt, UDInt, Real, LReal

Location of the first element in a onedimension array defined in a global data block
or block interface.
For example: If the array index is specified as
[-2..4], then the index of the first element is -2
and not 0.

Value 1

Out

Bool, Byte, Word, DWord, Char, SInt, Int,
Dint, USInt, UInt, UDInt, Real, LReal

Location to which the specified array element
is copied (FieldRead)
Location of the value that is copied to the
specified array element (FieldWrite)

The data type of the array element specified by the MEMBER parameter and the VALUE parameter must have the
same data type.

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The enable output ENO = 0, if one of the following conditions applies:
● The EN input has signal state "0"
● The array element specified at the INDEX parameter is not defined in the array
referenced at MEMBER parameter
● Errors such as an overflow occur during processing

7.6.3
Table 7- 67
LAD / FBD

Fill instructions
FILL_BLK and UFILL_BLK instructions
Description
Interruptible fill instruction: Fills an address range with copies of a specified data element

Uninterruptible fill instruction: Fills an address range with copies of a specified data element

Table 7- 68

Data types for parameters

Parameter

Data type

Description

SInt, Int, DIntT, USInt, UInt, UDInt, Real, LReal, Byte, Word, Data source address
DWord

COUNT

USInt, UInt

OUT

SInt, Int, DIntT, USInt, UInt, UDInt, Real, LReal, Byte, Word, Data destination address
DWord

Number of data elements to copy

Note
Rules for data fill operations
 To fill with the BOOL data type, use SET_BF, RESET_BF, R, S, or output coil (LAD)
 To fill with a single elementary data type, use MOVE
 To fill an array with an elementary data type, use FILL_BLK or UFILL_BLK
 To fill a single character in a string, use MOVE
 The FILL_BLK and UFILL_BLK instructions cannot be used to fill arrays in the I, Q, or M
memory areas.

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7.6 Move
The FILL_BLK and UFILL_BLK instructions copy the source data element IN to the
destination where the initial address is specified by the parameter OUT. The copy process
repeats and a block of adjacent addresses is filled until the number of copies is equal to the
COUNT parameter.
FILL_BLK and UFILL_BLK instructions differ in how interrupts are handled:
● Interrupt events are queued and processed during FILL_BLK execution. Use the
FILL_BLK instruction when the data at the move destination address is not used within an
interrupt OB subprogram or, if used, the destination data does not have to be consistent.
● Interrupt events are queued but not processed until UFILL_BLK execution is complete.
Use the UFILL_BLK instruction when the move operation must be completed and the
destination data consistent, before the execution of an interrupt OB subprogram.
Table 7- 69

7.6.4
Table 7- 70
LAD / FBD

ENO status

ENO

Condition

Result

No error

The IN element was successfully copied to
all COUNT destinations.

The destination (OUT) range exceeds
the available memory area

Elements that fit are copied. No partial
elements are copied.

Swap instruction
SWAP instruction
Description
Reverses the byte order for two-byte and four-byte data elements. No change is made to the bit order
within each byte. ENO is always TRUE following execution of the SWAP instruction.

For LAD and FBD: Click the "???" and select a data type from the drop-down menu.

Table 7- 71

Data types for the parameters

Parameter

Data type

Description

Word, DWord

Ordered data bytes IN

OUT

Word, DWord

Reverse ordered data bytes OUT

Example 1

Parameter IN = MB0
(before execution)

Parameter OUT = MB4,
(after execution)

Address

MB0

MB1

MB4

MB5

W#16#1234

WORD

MSB

LSB

MSB

LSB
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7.7 Convert

Example 2

Parameter IN = MB0
(before execution)

Address

MB0

MB1

MB2

MB3

MB4

MB5

MB6

MB7

DW#16#
12345678

DWORD

MSB

LSB

MSB

7.7

Convert

7.7.1

CONV instruction

Table 7- 72
LAD / FBD

Parameter OUT = MB4,
(after execution)

LSB

Convert (CONV) instruction
Description
Converts a data element from one data type to another data type.

For LAD and FBD: Click the "???" and select the data types from the drop-down menu.

Table 7- 73

Data types for the parameters

Parameter

Data type

Description

Byte, Word, DWord, SInt, USInt, Int, UInt, DInt, UDInt, Real,
LReal, Bcd16, Bcd32

Input value

OUT

Byte, Word, DWord, SInt, USInt, Int, UInt, DInt, UDInt, Real,
LReal, Bcd16, Bcd32

Input value converted to a new data type

After you select the (convert from) data type, a list of possible conversions is shown in the
(convert to) dropdown list. Conversions from and to BCD16 are restricted to the Int data
type. Conversions from and to BCD32 are restricted to the DInt data type.
Table 7- 74

ENO status

ENO

Description

Result OUT

No error

Valid result

IN is +/- INF or +/- NaN

+/- INF or +/- NaN

Result exceeds valid range for OUT data type

OUT is set to the least-significant bytes of IN

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7.7 Convert

7.7.2
Table 7- 75
LAD / FBD

Round and truncate instructions
ROUND and TRUNC instructions
Description
Converts a real number to an integer. The real number fraction is rounded to the nearest integer value
(IEEE - round to nearest). If the number is exactly one-half the span between two integers (for example,
10.5), then the number is rounded to the even integer. For example:


ROUND (10.5) = 10



ROUND (11.5) = 12

TRUNC converts a real number to an integer. The fractional part of the real number is truncated to zero
(IEEE - round to zero).

For LAD and FBD: Click the "???" (by the instruction name) and select a data type from the drop-down menu.

Table 7- 76

Data types for the parameters

Parameter

Data type

Real, LReal

Floating point input

OUT

SInt, Int, DInt, USInt, UInt, UDInt, Real, LReal

Rounded or truncated output

Table 7- 77

Description

ENO status

ENO

Description

Result OUT

No error

Valid result

IN is +/- INF or +/- NaN

+/- INF or +/- NaN

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7.7 Convert

7.7.3
Table 7- 78
LAD / FBD

Ceiling and floor instructions
CEIL and FLOOR instructions
Description
Converts a real number (Real or LReal) to the closest integer greater than or equal to the selected real
number (IEEE "round to +infinity").

Converts a real number (Real or LReal) to the closest integer smaller than or equal to the selected real
number (IEEE "round to -infinity").

For LAD and FBD: Click the "???" (by the instruction name) and select a data type from the drop-down menu.

Table 7- 79

Data types for the parameters

Parameter

Data type

Real, LReal

Floating point input

OUT

SInt, Int, DInt, USInt, UInt, UDInt, Real, LReal

Converted output

Table 7- 80

Description

ENO status

ENO

Description

Result OUT

No error

Valid result

IN is +/- INF or +/- NaN

+/- INF or +/- NaN

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7.7 Convert

7.7.4
Table 7- 81
LAD / FBD

Scale and normalize instructions
SCALE_X and NORM_X instructions
Description
Scales the normalized real parameter VALUE where ( 0.0 <= VALUE <= 1.0 ) in the data type and value
range specified by the MIN and MAX parameters:
OUT = VALUE (MAX - MIN) + MIN

Normalizes the parameter VALUE inside the value range specified by the MIN and MAX parameters:
OUT = (VALUE - MIN) / (MAX - MIN),
where ( 0.0 <= OUT <= 1.0 )

For LAD and FBD: Click the "???" and select a data type from the drop-down menu.

Table 7- 82

Data types for the parameters

Parameter

Data type1

Description

MIN

SInt, Int, DInt, USInt, UInt, UDInt, Real, LReal

Input minimum value for range

VALUE

SCALE_X: Real, LReal

Input value to scale or normalize

NORM_X: SInt, Int, DInt, USInt, UInt, UDInt, Real, LReal
MAX

SInt, Int, DInt, USInt, UInt, UDInt, Real, LReal

Input maximum value for range

OUT

SCALE_X: SInt, Int, DInt, USInt, UInt, UDInt, Real, LReal

Scaled or normalized output value

NORM_X: Real, LReal
1

For SCALE_X: Parameters MIN, MAX, and OUTmust be the same data type.
For NORM_X: Parameters MIN, VALUE, and MAXmust be the same data type.

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Note
SCALE_X parameter VALUE should be restricted to ( 0.0 <= VALUE <= 1.0 )
If parameter VALUE is less than 0.0 or greater than 1.0:
 The linear scaling operation can produce OUT values that are less than the parameter
MIN value or above the parameter MAX value for OUT values that fit within the value
range of the OUT data type. SCALE_X execution sets ENO = TRUE for these cases.
 It is possible to generate scaled numbers that are not within the range of the OUT data
type. For these cases, the parameter OUT value is set to an intermediate value equal to
the least-significant portion of the scaled real number prior to final conversion to the OUT
data type. SCALE_X execution sets ENO = FALSE in this case.
NORM_X parameter VALUE should be restricted to ( MIN <= VALUE <= MAX )
If parameter VALUE is less than MIN or greater than MAX, the linear scaling operation can
produce normalized OUT values that are less than 0.0 or greater than 1.0. NORM_X
execution sets ENO = TRUE in this case.

Table 7- 83

ENO status

ENO

Condition

Result OUT

No error

Valid result

Result exceeds valid range for the OUT data
type

Intermediate result: The least-significant portion of a real
number prior to final conversion to the OUT data type.

Parameters MAX <= MIN

SCALE_X: The least-significant portion of the Real number
VALUE to fill up the OUT size.
NORM_X: VALUE in VALUE data type extended to fill a
double word size.

Parameter VALUE = +/- INF or +/- NaN

VALUE is written to OUT

Example (LAD): normalizing and scaling an analog input value
An analog input from an analog signal module or signal board using input in current is in the
range 0 to 27648 for valid values. Suppose an analog input represents a temperature where
the 0 value of the analog input represents -30.0 degrees C and 27648 represents 70.0
degrees C.
To transform the analog value to the corresponding engineering units, normalize the input to
a value between 0.0 and 1.0, and then scale it between -30.0 and 70.0. The resulting value
is the temperature represented by the analog input in degrees C:

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Note that if the analog input was from an analog signal module or signal board using voltage,
the MIN value for the NORM_X instruction would be -27648 instead of 0.

Example (LAD): normalizing and scaling an analog output value
An analog output to be set in an analog signal module or signal board using output in current
must be in the range 0 to 27648 for valid values. Suppose an analog output represents a
temperature setting where the 0 value of the analog input represents -30.0 degrees C and
27648 represents 70.0 degrees C. To convert a temperature value in memory that is
between -30.0 and 70.0 to a value for the analog output in the range 0 to 27648, you must
normalize the value in engineering units to a value between 0.0 and 1.0, and then scale it to
the range of the analog output, 0 to 27648:

Note that if the analog output was for an analog signal module or signal board using voltage,
the MIN value for the SCALE_X instruction would be -27648 instead of 0.
Additional information on analog input representations (Page 607) and analog output
representations (Page 607) in both voltage and current can be found in the Technical
Specifications.

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7.8 Program control

7.8

Program control

7.8.1

Jump and label instructions

Table 7- 84
LAD

JMP, JMPN, and LABEL instruction
FBD

Description
If there is power flow to a JMP coil (LAD), or if the JMP box input is true (FBD),
then program execution continues with the first instruction following the specified
label.
If there is no power flow to a JMPN coil (LAD), or if the JMPN box input is false
(FBD), then program execution continues with the first instruction following the
specified label.
Destination label for a JMP or JMPN jump instruction

You create your label names by typing in the LABEL instruction directly. Use the parameter helper icon to select the
available label names for the JMP and JMPN label name field. You can also type a label name directly into the JMP or
JMPN instruction.

Table 7- 85

Data types for the parameters

Parameter

Data type

Description

Label_name

Label identifier

Identifier for Jump instructions and the corresponding jump
destination program label

● Each label must be unique within a code block.
● You can jump within a code block, but you cannot jump from one code block to another
code block.
● You can jump forward or backward.
● You can jump to the same label from more than one place in the same code block.

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7.8 Program control

7.8.2
Table 7- 86

JMP_LIST instruction
JMP_LIST instruction
Description

LAD / FBD ,

The JMP_LIST instruction acts as a program jump distributor to control the execution of program
sections. Depending on the value of the K input, a jump occurs to the corresponding program label.
Program execution continues with the program instructions that follow the destination jump label. If
the value of the K input exceeds the number of labels - 1, then no jump occurs and processing
continues with the next program network.

Table 7- 87

Data types for parameters

Parameter

Data type

Description

UInt

Jump distributor control value

DEST0, DEST1, ..,
DESTn.

Program Labels

Jump destination labels corresponding to specific K parameter values:
If the value of K equals 0, then a jump occurs to the program label
assigned to the DEST0 output. If the value of K equals 1, then a jump
occurs to the program label assigned to the DEST1 output, and so on. If
the value of the K input exceeds the (number of labels - 1), then no jump
occurs and processing continues with the next program network.

For LAD and FBD: The JMP_LIST box is first placed in your program, there are two jump
label outputs. You can add or delete jump destinations.
Click the create icon inside the box (on the left of the last DEST parameter)
to add new outputs for jump labels.

 Right-click on an output stub and select the "Insert output" command.
 Right-click on an output stub and select the "Delete" command.

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7.8.3
Table 7- 88
LAD / FBD

SWITCH instruction
SWITCH instruction
Description
The SWITCH instruction acts as a program jump distributor to control the execution of program
sections. Depending on the result of comparisons between the value of the K input and the values
assigned to the specified comparison inputs, a jump occurs to the program label that corresponds to the
first comparison test that is true. If none of the comparisons is true, then a jump to the label assigned to
ELSE occurs. Program execution continues with the program instructions that follow the destination
jump label.

For LAD and FBD: Click below the box name and select a data type from the drop-down menu.

Table 7- 89

Data types for parameters

Parameter

Data type1

SInt, Int, DInt, USInt, UInt, UDInt, Real, Common comparison value input
LReal, Byte, Word, DWord, Time,
TOD, Date

Description

==, <>, <, <=, >. >= SInt, Int, DInt, USInt, UInt, UDInt, Real, Separate comparison value inputs for specific comparison
LReal, Byte, Word, DWord, Time,
types
TOD, Date
DEST0, DEST1, ..,
DESTn. ELSE

Program Labels

Jump destination labels corresponding to specific
comparisons:
The comparison input below and next to the K input is
processed first and causes a jump to the label assigned to
DEST0, if the comparison between the K value and this
input is true. The next comparison test uses the next input
below and causes a jump to the label assigned to DEST1, if
the comparison is true, The remaining comparisons are
processed similarly and if none of the comparisons are true,
then a jump to the label assigned to the ELSE output
occurs.

The K input and comparison inputs (==, <>, <, <=, >, >=) must be the same data type.

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7.8 Program control

Adding inputs, deleting inputs, and specifying comparison types
When the LAD or FBD SWITCH box is first placed in your program there are two comparison
inputs. You can assign comparison types and add inputs/jump destinations, as shown below.
Click a comparison operator inside the box and select a new operator
from the drop-down list.

Click the create icon inside the box (to the left of the last DEST
parameter) to add new comparison-destination parameters.

 Right-click on an input stub and select the "Insert input" command.
 Right-click on an input stub and select the "Delete" command.

Table 7- 90

SWITCH box data type selection and allowed comparison operations

Data type

Comparison

Operator syntax

Byte, Word, DWord

Equal

Not equal

SInt, Int, DInt, USInt, UInt,
UDInt, Real, LReal, Time, TOD,
Date

Equal

Not equal

Greater than or equal

Less than or equal

Greater than

Less than

SWITCH box placement rules
● No LAD/FBD instruction connection in front of the compare input is allowed.
● There is no ENO output, so only one SWITCH instruction is allowed in a network and the
SWITCH instruction must be the last operation in a network.

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7.8 Program control

7.8.4

RET execution control instruction
The optional RET instruction is used to terminate the execution of the current block. If and
only if there is power flow to the RET coil (LAD) or if the RET box input is true (FBD), then
program execution of the current block will end at that point and instructions beyond the RET
instruction will not be executed. If the current block is an OB, the "Return_Value" parameter
is ignored. If the current block is a FC or FB, the value of the "Return_Value " parameter is
passed back to the calling routine as the ENO value of the called box.
You are not required to use a RET instruction as the last instruction in a block; this is done
automatically for you. You can have multiple RET instructions within a single block.

Table 7- 91

Return_Value (RET) execution control instruction

LAD

FBD

Description
Terminates the execution of the current block

Table 7- 92

Data types for the parameters

Parameter

Data type

Description

Return_Value

Bool

The "Return_value" parameter of the RET instruction is assigned to the ENO output
of the block call box in the calling block.

Sample steps for using the RET instruction inside an FC code block:
1. Create a new project and add an FC:
2. Edit the FC:
– Add instructions from the instruction tree.
– Add a RET instruction, including one of the following for the "Return_Value"
parameter:
TRUE, FALSE, or a memory location that specifies the required return value.
– Add more instructions.
3. Call the FC from MAIN [OB1].
The EN input on the FC box in the MAIN code block must be true to begin execution of the
FC.
The value specified by the RET instruction in the FC will be present on the ENO output of the
FC box in the MAIN code block following execution of the FC for which power flow to the
RET instruction is true.

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7.8 Program control

7.8.5

Re-trigger scan cycle watchdog instruction

Table 7- 93

RE_TRIGR instruction

LAD / FBD

Description
RE_TRIGR (Re-trigger scan time watchdog) is used to extend the maximum time allowed before the
scan cycle watchdog timer generates an error.

Use the RE_TRIGR instruction to restart the scan cycle timer during a single scan cycle. This
has the effect of extending the allowed maximum scan cycle time by one maximum cycle
time period, from the last execution of the RE_TRIGR function.
The CPU restricts the use of the RE_TRIGR instruction to the program cycle, for example,
OB1 and functions that are called from the program cycle. This means that the watchdog
timer is reset, and ENO = EN, if RE_TRIGR is called from any OB of the program cycle OB
list.
ENO = FALSE and the watchdog timer is not reset if RE_TRIGR is executed from a start up
OB, an interrupt OB, or an error OB.

Setting the PLC maximum cycle time
Configure the value for maximum scan cycle time in the Device configuration for "Cycle
time".
Table 7- 94

Cycle time values

Cycle time monitor

Minimum value

Maximum value

Default value

Maximum cycle time

1 ms

6000 ms

150 ms

Watchdog timeout
If the maximum scan cycle timer expires before the scan cycle has been completed, an error
is generated. If the error handling code block OB 80 is included in the user program, the
CPU executes OB 80 where you may add program logic to create a special reaction. If OB
80 is not included, the first timeout condition is ignored.
If a second maximum scan time timeout occurs in the same program scan (2 times the
maximum cycle time value), an error is triggered that causes the CPU to transition to STOP
mode.
In STOP mode, your program execution stops while CPU system communications and
system diagnostics continue.

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7.8 Program control

7.8.6
Table 7- 95
LAD / FBD

Stop scan cycle instruction
STP instruction
Description
STP (Stop scan cycle) puts the CPU in STOP mode. When the CPU is in STOP mode, the execution of
your program and physical updates from the process image are stopped.

For more information see: Configuring the outputs on a RUN-to-STOP transition (Page 78).
If EN = TRUE, then the CPU goes to STOP mode, the program execution stops, and the
ENO state is meaningless. Otherwise, EN = ENO = 0.

7.8.7

Get Error instructions
The get error instructions provide information about program block execution errors. If you
add a GetError or GetErrorID instruction to your code block, you can handle program errors
within your program block.

GetError
Table 7- 96
LAD / FBD

GetError instruction
Description
Indicates that a local program block execution error has occurred and fills a predefined error data
structure with detailed error information.

Table 7- 97

Data types for the parameters

Parameter

Data type

Description

ERROR

ErrorStruct

Error data structure: You can rename the structure, but not the members within the
structure.

Table 7- 98

Elements of the ErrorStruct data structure

Structure components

Data type

Description

ERROR_ID

Word

Error ID

FLAGS

Byte

Shows if an error occurred during a block call.


16#01: Error during a block call.



16#00: No error during a block call.

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Structure components

Data type

Description

REACTION

Byte

Default reaction:

CODE_ADDRESS
BLOCK_TYPE

CB_NUMBER
OFFSET
MODE



0: Ignore (write error),



1: Continue with substitute value "0" (read error),



2: Skip instruction (system error)

CREF

Information about the address and type of block

Byte

Type of block where the error occurred:

UInt



1: OB



2: FC



3: FB

Number of the code block

UDInt

Reference to the internal memory

Byte

Access mode: Depending on the type of access, the following
information can be output:
Mode

(A)

(B)

(C)

(D)

(E)

0
1

Offset

2
3

Area
Location

Scope

Number

Area

DB no.

Offset

Area

DB no.

Offset

Area

DB no.

Offset

PtrNo.
/Acc

PtrNo. /
Acc

Slot No. /
Scope

OPERAND_NUMBER

UInt

Operand number of the machine command

POINTER_NUMBER_
LOCATION

UInt

(A) Internal pointer

SLOT_NUMBER_SCOPE

UInt

(B) Storage area in internal memory

DATA_ADDRESS

NREF

Information about the address of an operand

Byte

AREA



L: 16#40 – 4E, 86, 87, 8E, 8F, C0 – CE



E: 16#81



A: 16#82



M: 16#83



DB: 16#84, 85, 8A, 8B

DB_NUMBER

UInt

(D) Number of the data block

OFFSET

UDInt

(E) Relative address of the operand

Offset

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GetErrorID
Table 7- 99

GetErrorID instruction

LAD / FBD

Description
Indicates that a program block execution error has occurred and reports the ID (identifier code) of the
error.

Table 7- 100 Data types for the parameters
Parameter

Data type

Description

Word

Error identifier values for the ErrorStruct ERROR_ID member

Table 7- 101 Error_ID values
ERROR_ID
Hexadecimal

ERROR_ID
Decimal

Program block execution error

No error

2503

9475

Uninitialized pointer error

2522

9506

Operand out of range read error

2523

9507

Operand out of range write error

2524

9508

Invalid area read error

2525

9509

Invalid area write error

2528

9512

Data alignment read error (incorrect bit alignment)

2529

9513

Data alignment write error (incorrect bit alignment)

2530

9520

DB write protected

253A

9530

Global DB does not exist

253C

9532

Wrong version or FC does not exist

253D

9533

Instruction does not exist

253E

9534

Wrong version or FB does not exist

253F

9535

Instruction does not exist

2575

9589

Program nesting depth error

2576

9590

Local data allocation error

2942

10562

Physical input point does not exist

2943

10563

Physical output point does not exist

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7.8 Program control

Operation
By default, the CPU responds to a block execution error by logging an error in the
diagnostics buffer. However, if you place one or more GetError or GetErrorID instructions
within a code block, this block is now set to handle errors within the block. In this case, the
CPU does not log an error in the diagnostics buffer. Instead, the error information is reported
in the output of the GetError or GetErrorID instruction. You can read the detailed error
information with the GetError instruction, or read just the error identifier with GetErrorID
instruction. Normally the first error is the most important, with the following errors only
consequences of the first error.
The first execution of a GetError or GetErrorID instruction within a block returns the first error
detected during block execution. This error could have occurred anywhere between the start
of the block and the execution of either GetError or GetErrorID. Subsequent executions of
either GetError or GetErrorID return the first error since the previous execution of GetError or
GetErrorID. The history of errors is not saved, and execution of either instruction will re-arm
the PLC system to catch the next error.
The ErrorStruct data type used by the GetError instruction can be added in the data block
editor and block interface editors, so your program logic can access these values. Select
ErrorStruct from the data type drop-down list to add this structure. You can create multiple
ErrorStruct elements by using unique names. The members of an ErrorStruct cannot be
renamed.

Error condition indicated by ENO
If EN = TRUE and GetError or GetErrorID executes, then:
● ENO = TRUE indicates a code block execution error occurred and error data is present
● ENO = FALSE indicates no code block execution error occurred
You can connect error reaction program logic to ENO which activates after an error occurs. If
an error exists, then the output parameter stores the error data where your program has
access to it.
GetError and GetErrorID can be used to send error information from the currently executing
block (called block) to a calling block. Place the instruction in the last network of the called
block program to report the final execution status of the called block.

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7.9 Word logic operations

7.9

Word logic operations

7.9.1

AND, OR, and XOR instructions

Table 7- 102 AND, OR, and XOR instruction
LAD / FBD

Description
AND: Logical AND
OR: Logical OR
XOR: Logical exclusive OR

For LAD and FBD: Click the "???" and select a data type from the drop-down menu.

To add an input, click the "Create" icon or right-click on an input stub for one of the
existing IN parameters and select the "Insert input" command.
To remove an input, right-click on an input stub for one of the existing IN parameters (when
there are more than the original two inputs) and select the "Delete" command.
Table 7- 103 Data types for the parameters

Parameter

Data type

Description

IN1, IN2

Byte, Word, DWord

Logical inputs

OUT

Byte, Word, DWord

Logical output

The data type selection sets parameters IN1, IN2, and OUT to the same data type.

The corresponding bit values of IN1 and IN2 are combined to produce a binary logic result at
parameter OUT. ENO is always TRUE following the execution of these instructions.

7.9.2

Invert instruction

Table 7- 104 INV instruction
LAD / FBD

Description
Calculates the binary one's complement of the parameter IN. The one's complement is formed by
inverting each bit value of the IN parameter (changing each 0 to 1 and each 1 to 0). ENO is always
TRUE following the execution of this instruction.

For LAD and FBD: Click the "???" and select a data type from the drop-down menu.

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Table 7- 105 Data types for the parameters
Parameter

Data type

Description

SInt, Int, DInt, USInt, UInt, UDInt, Byte, Word, DWord

Data element to invert

OUT

SInt, Int, DInt, USInt, UInt, UDInt, Byte, Word, DWord

Inverted output

7.9.3

Encode and decode instructions

Table 7- 106 ENCO and DECO instruction
LAD / FBD

Description
Encodes a bit pattern to a binary number
The ENCO instruction converts parameter IN to the binary number corresponding to the bit position of
the least-significant set bit of parameter IN and returns the result to parameter OUT. If parameter IN is
either 0000 0001 or 0000 0000, then a value of 0 is returned to parameter OUT. If the parameter IN
value is 0000 0000, then ENO is set to FALSE.
Decodes a binary number to a bit pattern
The DECO instruction decodes a binary number from parameter IN, by setting the corresponding bit
position in parameter OUT to a 1 (all other bits are set to 0). ENO is always TRUE following execution of
the DECO instruction.

For LAD and FBD: Click the "???" and select a data type from the drop-down menu.

Table 7- 107 Data types for the parameters
Parameter

Data type

Description

ENCO: Byte, Word, DWord

ENCO: Bit pattern to encode

DECO: UInt

DECO: Value to decode

ENCO: Int

ENCO: Encoded value

DECO: Byte, Word, DWord

DECO: Decoded bit pattern

OUT

Table 7- 108 OUT parameter for ENCO
ENO

Condition

Result (OUT)

No error

Valid bit number

IN is zero

OUT is set to zero

The DECO parameter OUT data type selection of a Byte, Word, or DWord restricts the
useful range of parameter IN. If the value of parameter IN exceeds the useful range, then a
modulo operation is performed to extract the least significant bits shown below.

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DECO parameter IN range:
● 3 bits (values 0-7) IN are used to set 1 bit position in a Byte OUT
● 4-bits (values 0-15) IN are used to set 1 bit position in a Word OUT
● 5 bits (values 0-31) IN are used to set 1 bit position in a DWord OUT
Table 7- 109 Examples
DECO IN value

DECO OUT value ( Decode single bit position)

Byte OUT

Min. IN

00000001

8 bits

Max. IN

10000000

Word OUT

Min. IN

0000000000000001

16 bits

Max. IN

1000000000000000

DWord OUT

Min. IN

00000000000000000000000000000001

32 bits

Max. IN

10000000000000000000000000000000

7.9.4

Select, Multiplex, and Demultiplex instructions

Table 7- 110 SEL (select) instruction
LAD / FBD

Description
SEL assigns one of two input values to parameter OUT, depending on the parameter G value.

For LAD and FBD: Click the "???" and select a data type from the drop-down menu.

Table 7- 111 Data types for the SEL instruction

Parameter

Data type 1

Description

Bool



0 selects IN0



1 selects IN1

IN0, IN1

SInt, Int, DInt, USInt, UInt, UDInt, Real, LReal, Byte, Word, DWord,
Time, Char

Inputs

OUT

SInt, Int, DInt, USInt, UInt, UDInt, Real, LReal, Byte, Word, DWord,
Time, Char

Output

Input variables and the output variable must be of the same data type.

Condition codes: ENO is always TRUE following execution of the SEL instruction.

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7.9 Word logic operations
Table 7- 112 MUX (multiplex) instruction
LAD / FBD

Description
MUX copies one of many input values to parameter OUT, depending on the parameter K value. If the
parameter K value exceeds (INn - 1), then the parameter ELSE value is copied to parameter OUT.

For LAD and FBD: Click the "???" and select a data type from the drop-down menu.

Parameter

Data type

Description

UInt



0 selects IN0



1 selects IN1



n selects INn

IN0, IN1, .. INn

SInt, Int, DInt, USInt, UInt, UDInt, Real, LReal, Byte, Word, DWord,
Time, Char

Inputs

ELSE

SInt, Int, DInt, USInt, UInt, UDInt, Real, LReal, Byte, Word, DWord,
Time, Char

Input substitute value (optional)

OUT

SInt, Int, DInt, USInt, UInt, UDInt, Real, LReal, Byte, Word, DWord,
Time, Char

Output

Input variables and the output variable must be of the same data type.

Table 7- 114 DEMUX (Demultiplex) instruction
LAD / FBD

Description
DEMUX copies the value of the location assigned to parameter IN to one of many outputs. The value of
the K parameter selects which output selected as the destination of the IN value. If the value of K is
greater than the number (OUTn - 1) then the IN value is copied to location assigned to the ELSE
parameter.

For LAD and FBD: Click the "???" and select a data type from the drop-down menu.

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To add an output, click the create icon or right-click on an output stub for one of the existing
OUT parameters and select the "Insert output" command. To remove an output, right-click
on an output stub for one of the existing OUT parameters (when there are more than the
original two outputs) and select the "Delete" command.
To add an output, click the "Create" icon or right-click on an output stub for one
of the existing OUT parameters and select the "Insert output" command.
To remove an output, right-click on an output stub for one of the existing OUT parameters
(when there are more than the original two outputs) and select the "Delete" command.
Table 7- 115 Data types for the DEMUX instruction
Parameter

Data type 1

Description

UInt

Selector value:


0 selects OUT0



1 selects OUT1



n selects OUTn

SInt, Int, DInt, USInt, UInt, UDInt, Real, LReal, Byte, Word, DWord,
Time, Char

Input

OUT0, OUT1, ..
OUTn

SInt, Int, DInt, USInt, UInt, UDInt, Real, LReal, Byte, Word, DWord,
Time, Char

Outputs

ELSE

SInt, Int, DInt, USInt, UInt, UDInt, Real, LReal, Byte, Word, DWord,
Time, Char

Substitute output when K is
greater than (OUTn - 1)

The input variable and the output variables must be of the same data type.

Table 7- 116 ENO status for the MUX and DEMUX instructions
ENO

Condition

No error

Result OUT
MUX: Selected IN value is copied to OUT
DEMUX: IN value is copied to selected OUT

MUX: K is greater than the number of inputs -1
DEMUX: K is greater than the number of outputs -1



No ELSE provided: OUT is unchanged,



ELSE provided, ELSE value assigned to OUT



No ELSE provided: outputs are unchanged,



ELSE provided, IN value copied to ELSE

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7.10 Shift and Rotate

7.10

Shift and Rotate

7.10.1

Shift instructions

Table 7- 117 SHR and SHL instructions
LAD / FBD

Description
Use the shift instructions (SHL and SHR) to shift the bit pattern of parameter IN. The result is assigned
to parameter OUT. Parameter N specifies the number of bit positions shifted:


SHR: Shift bit pattern right



SHL: Shift bit pattern left

For LAD and FBD: Click the "???" and select the data types from the drop-down menu.

Table 7- 118 Data types for the parameters
Parameter

Data type

Description

Byte, Word, DWord

Bit pattern to shift

UInt

Number of bit positions to shift

OUT

Byte, Word, DWord

Bit pattern after shift operation

● For N=0, no shift occurs. The IN value is assigned to OUT.
● Zeros are shifted into the bit positions emptied by the shift operation.
● If the number of positions to shift (N) exceeds the number of bits in the target value (8 for
Byte, 16 for Word, 32 for DWord), then all original bit values will be shifted out and
replaced with zeros (zero is assigned to OUT).
● ENO is always TRUE for the shift operations.
Table 7- 119 SHL example for Word data
Shift the bits of a Word to the left by inserting zeroes from the right (N = 1)
IN

1110 0010 1010 1101

OUT value before first shift:

1110 0010 1010 1101

After first shift left:

1100 0101 0101 1010

After second shift left:

1000 1010 1011 0100

After third shift left:

0001 0101 0110 1000

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7.10 Shift and Rotate

7.10.2

Rotate instructions

Table 7- 120 ROR and ROL instructions
LAD / FBD

Description
Use the rotate instructions (ROR and ROL) to rotate the bit pattern of parameter IN. The result is
assigned to parameter OUT. Parameter N defines the number of bit positions rotated.


ROR: Rotate bit pattern right



ROL: Rotate bit pattern left

For LAD and FBD: Click the "???" and select the data types from the drop-down menu.

Table 7- 121 Data types for the parameters
Parameter

Data type

Description

Byte, Word, DWord

Bit pattern to rotate

UInt

Number of bit positions to rotate

OUT

Byte, Word, DWord

Bit pattern after rotate operation

● For N=0, no rotate occurs. The IN value is assigned to OUT.
● Bit data rotated out one side of the target value is rotated into the other side of the target
value, so no original bit values are lost.
● If the number of bit positions to rotate (N) exceeds the number of bits in the target value
(8 for Byte, 16 for Word, 32 for DWord), then the rotation is still performed.
● ENO is always TRUE following execution of the rotate instructions.
Table 7- 122 ROR example for Word data
Rotate bits out the right -side into the left -side (N = 1)
IN

0100 0000 0000 0001

OUT value before first rotate:

0100 0000 0000 0001

After first rotate right:

1010 0000 0000 0000

After second rotate right:

0101 0000 0000 0000

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8.1

Date and time-of-day

8.1.1

Date and time instructions
Use the date and time instructions to program calendar and time calculations.
● T_CONV converts the data type of a time value: (Time to DInt) or (DInt to Time)
● T_ADD adds Time and DTL values: (Time + Time = Time) or (DTL + Time = DTL)
● T_SUB subtracts Time and DTL values: (Time - Time = Time) or (DTL - Time = DTL)
● T_DIFF provides the difference between two DTL values as a Time value: DTL - DTL =
Time
● T_COMBINE combines a Date value and a Time_and_Date value to create a DTL value
For information about the structure of the DTL and Time data, refer to the section on the
Time and Date data types (Page 87).

Table 8- 1

T_CONV (Time Convert) instruction

LAD / FBD

Description
T_CONV converts a Time data type to a DInt data type, or the reverse conversion from DInt data type to
Time data type.

For LAD and FBD: Click the "???" and select the data types from the drop-down menu.

Table 8- 2

Data types for the T_CONV parameters

Parameter and type

Data type

Description

DInt, Time

Input Time value or DInt value

OUT

DInt, Time

Converted DInt value or Time value

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8.1 Date and time-of-day
Table 8- 3

T_ADD (Time Add) and T_SUB (Time Subtract) instructions

LAD / FBD

Description
T_ADD adds the input IN1 value (DTL or Time data types) with the input IN2 Time value. Parameter
OUT provides the DTL or Time value result. Two data type operations are possible:


Time + Time = Time



DTL + Time = DTL

T_SUB subtracts the IN2 Time value from IN1 (DTL or Time value). Parameter OUT provides the
difference value as a DTL or Time data type. Two data type operations are possible:



Time - Time = Time



DTL - Time = DTL

For LAD and FBD: Click the "???" and select the data types from the drop-down menu.

Table 8- 4

Data types for the T_ADD and T_SUB parameters

Parameter and type

IN11
IN2
OUT

Data type

Description

DTL, Time

DTL or Time value

Time

Time value to add or subtract

OUT

DTL, Time

DTL or Time sum or difference

Select the IN1 data type from the drop-down list available below the instruction name. The IN1 data type selection also
sets the data type of parameter OUT.

Table 8- 5

T_DIFF (Time Difference) instruction

LAD / FBD

Description
T_DIFF subtracts the DTL value (IN2) from the DTL value (IN1). Parameter OUT provides the difference
value as a Time data type.
DTL - DTL = Time



Table 8- 6

Data types for the T_DIFF parameters

Parameter and type

Data type

Description

IN1

DTL

DTL value

IN2

DTL

DTL value to subtract

OUT

Time

Time difference

Condition codes: ENO = 1 means no error occurred. ENO = 0 and parameter OUT = 0
errors:
● Invalid DTL value
● Invalid Time value

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8.1 Date and time-of-day
Table 8- 7

T_COMBINE (combine time values) instruction

LAD / FBD

Description
T_COMBINE combines a Date value and a Time_of_Day value to create a DTL value.

Table 8- 8

Data types for the T_COMBINE parameters

Parameter and type

Data type

Description

IN1

Date

Date value to be combined must be between DATE#199001-01 and DATE#2089-12-31

, IN2

Time_of_Day

Time_of_Day values to be combined

OUT

DTL

DTL value

8.1.2

Set and read system clock
Use the clock instructions to set and read the CPU system clock. The data type DTL
(Page 87) is used to provide date and time values.

Table 8- 9
LAD / FBD

System time instructions
Description
WR_SYS_T (Write System Time) sets the CPU time of day clock with a DTL value at parameter IN. This
time value does not include local time zone or daylight saving time offsets.
RD_SYS_T (Read System Time) reads the current system time from the CPU. This time value does not
include local time zone or daylight saving time offsets.

RD_LOC_T (Read Local Time) provides the current local time of the CPU as a DTL data type. This time
value reflects the local time zone adjusted appropriately for daylight saving time (if configured).

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8.1 Date and time-of-day
Table 8- 10

Data types for the parameters

Parameter and type

Data type

Description

DTL

Time of day to set in the CPU system clock

RET_VAL

OUT

Int

Execution condition code

OUT

DTL

RD_SYS_T: Current CPU system time
RD_LOC_T: Current local time. including any adjustment for
daylight saving time, if configured

● The local time is calculated by using the time zone and daylight saving time offsets that
you set in the device configuration general tab "Time of day" parameters.
● Time zone configuration is an offset to UTC or GMT time.
● Daylight saving time configuration specifies the month, week, day, and hour when
daylight saving time begins.
● Standard time configuration also specifies the month, week, day, and hour when standard
time begins.
● The time zone offset is always applied to the system time value. The daylight saving time
offset is only applied when daylight saving time is in effect.
Note
Daylight saving and standard start time configuration
The "Time of day" properties for "Start for daylight saving time" of the CPU device
configuration must be your local time.
Condition codes: ENO = 1 means no error occurred. ENO = 0 means an execution error
occurred, and a condition code is provided at the RET_VAL output.
Table 8- 11

Condition codes

RET_VAL (W#16#....)

Description

0000

No error

8080

Local time not available

8081

Illegal year value

8082

Illegal month value

8083

Illegal day value

8084

Illegal hour value

8085

Illegal minute value

8086

Illegal second value

8087

Illegal nanosecond value

80B0

The real-time clock has failed

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8.1 Date and time-of-day

8.1.3

Run-time meter instruction

Table 8- 12

RTM instruction

LAD / FBD

Description
The RTM (Run Time Meter) instruction can set, start, stop, and read the run-time hour meters in the CPU.

Table 8- 13

Data types for the parameters

Parameter and type

Data type

Description

UInt

Run-time meter number: (possible values: 0..9)

MODE

Byte

RTM Execution mode number:


0 = Fetch values (the status is then written to CQ and the
current value to CV)



1 = Start (at the last counter value)



2 = Stop



4 = Set (to the value specified in PV)



5 = Set (to the value specified in PV) and then start



6 = Set (to the value specified in PV) and then stop



7 = Save all RTM values in the CPU to the MC (Memory
Card)

DInt

Preset hours value for the specified run-time meter

RET_VAL

OUT

Int

Function result / error message

OUT

Bool

Run-time meter status (1 = running)

OUT

DInt

Current run-time hours value for the specified meter

The CPU operates up to 10 run-time hour meters to track the run-time hours of critical
control subsystems. You must start the individual hour meters with one RTM execution for
each timer. All run-time hour meters are stopped when the CPU makes a run-to-stop
transition. You can also stop individual timers with RTM execution mode 2.
When a CPU makes a stop-to-run transition, you must restart the hour timers with one RTM
execution for each timer that is started. After a run-time meter value is greater than
2147483647 hours, counting stops and the "Overflow" error is sent. You must execute the
RTM instruction once for each timer to reset or modify the timer.
A CPU power failure or power cycle causes a power-down process that saves the current
run-time meter values in retentive memory. Upon CPU power-up, the stored run-time meter
values are reloaded to the timers and the previous run-time hour totals are not lost. The runtime meters must be restarted to accumulate additional run-time.

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8.1 Date and time-of-day
Your program can also use RTM execution mode 7 to save the run-time meter values in a
memory card. The states of all timers at the instant RTM mode 7 is executed are stored in
the memory card. These stored values can become incorrect over time as the hour timers
are started and stopped during a program run session. You must periodically update the
memory card values to capture important run-time events. The advantage that you get from
storing the RTM values in the memory card is that you can insert the memory card in a
substitute CPU where your program and saved RTM values will be available. If you did not
save the RTM values in the memory card, then the timer values would be lost (in a substitute
CPU).
Note
Avoid excessive program calls for memory card write operations
Minimize flash memory card write operations to extend the life of the memory card.

Table 8- 14

Condition codes

RET_VAL (W#16#....)

Description

No error

8080

Incorrect run-time meter number

8081

A negative value was passed to the parameter PV

8082

Overflow of the operating hours counter

8091

The input parameter MODE contains an illegal value.

80B1

Value cannot be saved to MC (MODE=7)

8.1.4
Table 8- 15
LAD / FBD

SET_TIMEZONE instruction
SET_TIMEZONE instruction
Description
Sets the local time zone and daylight saving parameters that are used to transform the
CPU system time to local time.

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8.1 Date and time-of-day
Table 8- 16

Data types for the parameters

Parameter and type

Data type

Description

REQ

Bool

REQ=1: execute function

Timezone

TimeTransformationRule

Rules for the transformation from system time to
local time

DONE

OUT

Bool

Function complete

BUSY

OUT

Bool

Function busy

ERROR

OUT

Bool

Error detected

STATUS

OUT

Word

Function result / error message

To manually configure the time zone parameters for the CPU, use the "Time of day"
properties of the "General" tab of the device configuration.
Use the SET_TIMEZONE instruction to set the local time configuration programmatically.
The parameters of the "TimeTransformationRule" structure specify the local time zone and
timing for automatic switching between standard time and daylight saving time.
Table 8- 17

"TimeTransformationRule" structure

Parameter

Data type

Description

Bias

Int

Time difference between UTC and local time [min]

DaylightBias

Int

Time difference between winter and summer time [min]

DaylightStartMonth

USInt

Month of daylight saving time

DaylightStartWeek

USInt

Week of daylight saving time:

DaylightStartWeekday

USInt



1 = First occurrence of the weekday in the month



...



5 = Last occurrence of the weekday of the month

Weekday of daylight saving time:


1 = Sunday



...



7 = Saturday

DaylightStartHour

USInt

Hour of daylight saving time

StandardStartMonth

USInt

Month of switching to winter time

StandardStartWeek

USInt

Week of the changeover to winter time:

StandardStartWeekday

USInt

StandardStartHour

USInt

Time Zone Name

STRING [80]



1 = First occurrence of the weekday in the month



...



5 = last occurrence of the weekday of the month

Weekday of winter time:


1 = Sunday



...



7 = Saturday

Hour of the winter time
Name of the zone:
(GMT +01:00) Amsterdam, Berlin, Bern, Rome, Stockholm, Vienna

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Extended instructions
8.2 String and character

8.2

String and character

8.2.1

String data overview

String data type
String data is stored as a 2-byte header followed by up to 254 character bytes of ASCII
character codes. A String header contains two lengths. The first byte is the maximum length
that is given in square brackets when you initialize a string, or 254 by default. The second
header byte is the current length that is the number of valid characters in the string. The
current length must be smaller than or equal to the maximum length. The number of stored
bytes occupied by the String format is 2 bytes greater than the maximum length.

Initialize your String data
String input and output data must be initialized as valid strings in memory, before execution
of any string instructions.

Valid String data
A valid string has a maximum length that must be greater than zero but less than 255. The
current length must be less than or equal to the maximum length.
Strings cannot be assigned to I or Q memory areas.
For more information see: Format of the String data type (Page 87).

8.2.2

S_MOVE instruction

Table 8- 18

String move instruction

LAD / FBD

Description
Copy the source IN string to the OUT location. S_MOVE execution does not affect the contents of the
source string.

Table 8- 19

Data types for the parameters

Parameter

Data type

Description

String

Source string

OUT

String

Target address

If the actual length of the string at the input IN exceeds the maximum length of a string
stored at output OUT, then the part of the IN string which can fit in the OUT string is copied.
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8.2 String and character

8.2.3

String conversion instructions

8.2.3.1

String to value and value to string conversions
You can convert number character strings to number values or number values to number
character strings with these instructions:
● S_CONV converts (number string to a number value) or (number value to a number
string)
● STRG_VAL converts a number string to a number value with format options
● VAL_STRG converts a number value to a number string with format options

S_CONV (String to value conversions)
Table 8- 20

String conversion instruction

LAD / FBD

Description
Converts a character string to the corresponding value, or a value to the corresponding character string.
The S_CONV instruction has no output formatting options. This makes the S_CONV instruction simpler,
but less flexible than the STRG_VAL and VAL_STRG instructions.

For LAD / FBD: Click the "???" and select the data type from the drop-down list.

Table 8- 21

Data types (string to value)

Parameter and type

Data type

Description

String

Input character string

OUT

String, Char, SInt, Int, DInt, USInt, UInt, UDInt, Real, LReal

Output number value

Conversion of the string parameter IN starts at the first character and continues until the end
of the string, or until the first character is encountered that is not "0" through "9", "+", "-", or
".". The result value is provided at the location specified in parameter OUT. If the output
number value does not fit in the range of the OUT data type, then parameter OUT is set to 0
and ENO is set to FALSE. Otherwise, parameter OUT contains a valid result and ENO is set
to TRUE.
Input String format rules:
● If a decimal point is used in the IN string, you must use the "." character.
● Comma characters "," used as a thousands separator to the left of the decimal point are
allowed and ignored.
● Leading spaces are ignored.
● Only fixed-point representation is supported. The characters "e" and "E" are not
recognized as exponential notation.

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8.2 String and character

S_CONV (Value to string conversions)
Table 8- 22

Data types (value to string)

Parameter and type

Data type

Description

String, Char, SInt, Int, DInt, USInt, UInt, UDInt, Real, LReal

Input number value

OUT

String

Output character string

An integer, unsigned integer, or floating point value IN is converted to the corresponding
character string at OUT. The parameter OUT must reference a valid string before the
conversion is executed. A valid string consists of a maximum string length in the first byte,
the current string length in the second byte, and the current string characters in the next
bytes. The converted string replaces characters in the OUT string starting at the first
character and adjusts the current length byte of the OUT string. The maximum length byte of
the OUT string is not changed.
How many characters are replaced depends on the parameter IN data type and number
value. The number of characters replaced must fit within the parameter OUT string length.
The maximum string length (first byte) of the OUT string should be greater than or equal to
the maximum expected number of converted characters. The following table shows the
maximum possible string lengths required for each supported data type.
Table 8- 23
IN data type

Maximum string lengths for each data type
Maximum number of converted
characters in OUT string

Example

Total string length including maximum and
current length bytes

USInt

255

SInt

-128

UInt

65535

Int

-32768

UDInt

4294967295

DInt

-2147483648

Output String format rules:
● Values written to parameter OUT do not use a leading "+" sign.
● Fixed-point representation is used (no exponential notation).
● The period character "." is used to represent the decimal point when parameter IN is the
Real data type.

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8.2 String and character

STRG_VAL instruction
Table 8- 24

String-to-value instruction

LAD / FBD

Description
Converts a number character string to the corresponding integer or floating point
representation.

For LAD / FBD: Click the "???" and select the data type from the drop-down list.

Table 8- 25

Data types for the STRG_VAL instruction
Data type

Description

Parameter and type
IN

String

The ASCII character string to convert

FORMAT

Word

Output format options

UInt, Byte, USInt

IN: Index to the first character to be converted
(first character = 1)

OUT

SInt, Int, DInt, USInt, UInt, UDInt,
Real, LReal

Converted number value

Conversion begins in the string IN at character offset P and continues until the end of the
string, or until the first character is encountered that is not "+", "-", ".", ",", "e", "E", or "0" to
"9". The result is placed at the location specified in parameter OUT.
String data must be initialized before execution as a valid string in memory.
The FORMAT parameter for the STRG_VAL instruction is defined below. The unused bit
positions must be set to zero.
Table 8- 26

Format of the STRG_VAL instruction

Bit
16
0

Bit 8 Bit 7
0

Bit 0
0

f = Notation format

1= Exponential notation
0 = Fixed point notation

r = Decimal point format

1 = "," (comma character)
0 = "." (period character)

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Table 8- 27

Values of the FORMAT parameter

FORMAT (W#16#)

Notation format

Decimal point representation

0000 (default)

Fixed point

"."

0001

","
Exponential

0002

"."

0003

","

0004 to FFFF

Illegal values

Rules for STRG_VAL conversion:
● If the period character "." is used for the decimal point, then commas "," to the left of the
decimal point are interpreted as thousands separator characters. The comma characters
are allowed and ignored.
● If the comma character "," is used for the decimal point, then periods "." to the left of the
decimal point are interpreted as thousands separator characters. These period
characters are allowed and ignored.
● Leading spaces are ignored.

VAL_STRG instruction
Table 8- 28

Value-to-string operation

LAD / FBD

Description
Converts an integer, unsigned integer, or floating point value to the corresponding character
string representation.

For LAD / FBD: Click the "???" and select the data type from the drop-down list.

Table 8- 29

Data types for the VAL_STRG instruction

Parameter and type

Data type

Description

SInt, Int, DInt, USInt, UInt, Value to convert
UDInt, Real, LReal

SIZE

USInt

Number of characters to be written to the OUT string

PREC

USInt

The precision or size of the fractional portion. This does
not include the decimal point.

FORMAT

Word

Output format options

UInt, Byte, USInt

IN: Index to the first OUT string character to be replaced
(first character = 1)

OUT

String

The converted string

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8.2 String and character
The value represented by parameter IN is converted to a string referenced by parameter
OUT. The parameter OUT must be a valid string before the conversion is executed.
The converted string will replace characters in the OUT string starting at character offset
count P to the number of characters specified by parameter SIZE. The number of characters
in SIZE must fit within the OUT string length, counting from character position P. This
instruction is useful for embedding number characters into a text string. For example, you
can put the numbers "120" into the string "Pump pressure = 120 psi".
Parameter PREC specifies the precision or number of digits for the fractional part of the
string. If the parameter IN value is an integer, then PREC specifies the location of the
decimal point. For example, if the data value is 123 and PREC = 1, then the result is "12.3".
The maximum supported precision for the Real data type is 7 digits.
If parameter P is greater than the current size of the OUT string, then spaces are added, up
to position P, and the result is appended to the end of the string. The conversion ends if the
maximum OUT string length is reached.
The FORMAT parameter for the VAL_STRG instruction is defined below. The unused bit
positions must be set to zero.
Table 8- 30

Format of the VAL_STRG instruction

Bit
16
0

Table 8- 31

Bit 8 Bit 7
0

Bit 0
0

s = Number sign character

1= use sign character "+" and "-"
0 = use sign character "-" only

f = Notation format

1= Exponential notation
0 = Fixed point notation

r = Decimal point format

1 = "," (comma character)
0 = "." (period character)

Values of the FORMAT parameter

FORMAT (WORD)

Number sign character

Notation format

Decimal point representation

W#16#0000

"-" only

Fixed point

"."

W#16#0001

","
Exponential

W#16#0002

","

W#16#0003
W#16#0004

"+" and "-"

Fixed Point

W#16#0005

"."
","

Exponential

W#16#0006

"."
","

W#16#0007
W#16#0008 to W#16#FFFF

"."

Illegal values

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8.2 String and character
Parameter OUT string format rules:
● Leading space characters are added to the leftmost part of the string when the converted
string is smaller than the specified size.
● When the FORMAT parameter sign bit is FALSE, unsigned and signed integer data type
values are written to the output buffer without the leading "+" sign. The "-" sign is used if
required.
'.'
● When the sign bit is TRUE, unsigned and signed integer data type values are written to
the output buffer always with a leading sign character.
'.'
● When the FORMAT is set to exponential notation, Real data type values are written to the
output buffer as:
'.' 'E'
● When the FORMAT is set to fixed point notation, integer, unsigned integer, and real data
type values are written to the output buffer as:
'.'
● Leading zeros to the left of the decimal point (except the digit adjacent to the decimal
point) are suppressed.
● Values to the right of the decimal point are rounded to fit in the number of digits to the
right of the decimal point specified by the PREC parameter.
● The size of the output string must be a minimum of three bytes more than the number of
digits to the right of the decimal point.
● Values are right-justified in the output string.

Conditions reported by ENO
When an error is encountered during the conversion operation, the following results will be
returned:
● ENO is set to 0.
● OUT is set to 0, or as shown in the examples for string to value conversion.
● OUT is unchanged, or as shown in the examples when OUT is a string.
Table 8- 32

ENO status

ENO

Description

No error

Illegal or invalid parameter; for example, an access to a DB that does not exist

Illegal string where the maximum length of the string is 0 or 255

Illegal string where the current length is greater than the maximum length

The converted number value is too large for the specified OUT data type.

The OUT parameter maximum string size must be large enough to accept the number of characters
specified by parameter SIZE, starting at the character position parameter P.

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8.2 String and character

ENO

Description

Illegal P value where P=0 or P is greater than the current string length

Parameter SIZE must be greater than parameter PREC.

Table 8- 33

Examples of S_CONV string to value conversion

IN string

OUT data type

OUT value

ENO

"123"

Int or DInt

123

TRUE

"-00456"

Int or DInt

-456

TRUE

"123.45"

Int or DInt

123

TRUE

"+2345"

Int or DInt

2345

TRUE

"00123AB"

Int or DInt

123

TRUE

"123"

Real

123.0

TRUE

"123.45"

Real

123.45

TRUE

"1.23e-4"

Real

1.23

TRUE

"1.23E-4"

Real

1.23

TRUE

"12,345.67"

Real

12345.67

TRUE

"3.4e39"

Real

3.4

TRUE

"-3.4e39"

Real

-3.4

TRUE

"1.17549e-38"

Real

1.17549

TRUE

"12345"

SInt

FALSE

"A123"

N/A

FALSE

N/A

FALSE

"++123"

N/A

FALSE

"+-123"

N/A

FALSE

Table 8- 34

Examples of S_CONV value to string conversion

Data type

IN value

OUT string

ENO

UInt

123

"123"

TRUE

UInt

"0"

TRUE

UDInt

12345678

"12345678"

TRUE

Real

-INF

"INF"

FALSE

Real

+INF

"INF"

FALSE

Real

NaN

"NaN"

FALSE

Table 8- 35

Examples of STRG_VAL conversion

IN string

FORMAT
(W#16#....)

OUT data type

OUT value

ENO

"123"

0000

Int or DInt

123

TRUE

"-00456"

0000

Int or DInt

-456

TRUE

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Extended instructions
8.2 String and character

IN string

FORMAT
(W#16#....)

OUT data type

OUT value

ENO

"123.45"

0000

Int or DInt

123

TRUE

"+2345"

0000

Int or DInt

2345

TRUE

"00123AB"

0000

Int or DInt

123

TRUE

"123"

0000

Real

123.0

TRUE

"-00456"

0001

Real

-456.0

TRUE

"+00456"

0001

Real

456.0

TRUE

"123.45"

0000

Real

123.45

TRUE

"123.45"

0001

Real

12345.0

TRUE

"123,45"

0000

Real

12345.0

TRUE

"123,45"

0001

Real

123.45

TRUE

".00123AB"

0001

Real

123.0

TRUE

"1.23e-4"

0000

Real

1.23

TRUE

"1.23E-4"

0000

Real

1.23

TRUE

"1.23E-4"

0002

Real

1.23E-4

TRUE

"12,345.67"

0000

Real

12345.67

TRUE

"12,345.67"

0001

Real

12.345

TRUE

"3.4e39"

0002

Real

+INF

TRUE

"-3.4e39"

0002

Real

-INF

TRUE

"1.1754943e-38"
(and smaller)

0002

Real

0.0

TRUE

"12345"

N/A

SInt

FALSE

"A123"

N/A

FALSE

N/A

FALSE

"++123"

N/A

FALSE

"+-123"

N/A

FALSE

The following examples of VAL_STRG conversions are based on an OUT string initialized as
follows:
"Current Temp = xxxxxxxxxx C"
where the "x" character represents space characters allocated for the converted value.
Table 8- 36

Examples of VAL_STRG conversion

Data type

IN value

SIZE

FORMAT
(W#16#....)

PREC

UInt

123

0000

UInt

0000

UDInt

12345678

0000

UDInt

12345678

0001

Int

123

0004

Int

-123

0004

Real

-0.00123

0004

OUT string
Current Temp
xxxxxxx123 C
Current Temp
xxxxxx0.00 C
Current Temp
x12345.678 C
Current Temp
x12345,678 C
Current Temp
xxxxxx+123 C
Current Temp
xxxxxx-123 C
Current Temp
0.0012 C

ENO
=

TRUE

= xxx-

TRUE

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Extended instructions
8.2 String and character

Data type

IN value

SIZE

FORMAT
(W#16#....)

PREC

Real

-0.00123

0006

Real

-INF

N/A

Real

+INF

N/A

Real

NaN

N/A

UDInt

12345678

N/A

8.2.3.2

OUT string
Current Temp
1.2300E-3 C
Current Temp
xxxxxx-INF C
Current Temp
xxxxxx+INF C
Current Temp
xxxxxxxNaN C
Current Temp
xxxxxxxxxx C

ENO
= -

TRUE

FALSE

String-to-characters and characters-to-string conversions
Chars_TO_Strg copies an array of ASCII character bytes into a character string.
Strg_TO_Chars copies an ASCII character string into an array of character bytes.
Note
Only the zero based array types (Array [0..n] of Char) or (Array [0..n] of Byte) are allowed as
the input parameter Chars for the Chars_TO_Strg instruction, or as the IN_OUT parameter
Chars for the Strg_TO_Chars instruction.

Table 8- 37

Chars_TO_Strg instruction

LAD / FBD

Description
All or part of an array of characters is copied to a string.
The output string must be declared before Chars_TO_Strg is executed. The string is then overwritten
by the Chars_TO_Strg operation.
Strings of all supported maximum lengths (1..254) may be used.
The string maximum length value is not changed by Chars_TO_Strg operation. Copying from array to
string stops when the maximum string length is reached.
A nul character '$00' or 16#00 value in the character array works as a delimiter and ends copying of
characters into the string.

Table 8- 38

Data types for the parameters (Chars_TO_Strg)

Parameter and type

Data type

Description

Chars

Variant

The Chars parameter is a pointer to zero based array [0..n] of
characters to be converted into a string. The array can be
declared in a DB or as local variables in the block interface.
Example: "DB1".MyArray points to MyArray [0..10] of Char
element values in DB1.

pChars

Dint

Element number for the first character in the array to copy.
Array element [0] is the default value.

Cnt

UInt

Count of characters to copy: 0 means all

Strg

OUT

String

Target string

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Table 8- 39

Strg_TO_Chars instruction

LAD / FBD

Description
The complete input string Strg is copied to an array of characters at IN_OUT parameter Chars.
The operation overwrites bytes starting at array element number specified by the pChars parameter.
Strings of all supported max lengths (1..254) may be used.
An end delimiter is not written; this is your responsibility. To set an end delimiter just after the last
written array character, use the next array element number [pChars+Cnt].

Table 8- 40

Data types for the parameters (Strg_TO_Chars)

Parameter and type

Data type

Description

Strg

String

Source string

pChars

DInt

Array element number for the first string character written to
the target array

Chars

IN_OUT

Variant

The Chars parameter is a pointer to zero based array [0..n] of
characters copied from the input string. The array can be
declared in a DB or as local variables in the block interface.
Example: "DB1".MyArray points to MyArray [0..10] of Char
element values in DB1.

Cnt

OUT

UInt

Count of characters copied

Table 8- 41

ENO status

ENO

Description

No error

Chars_TO_Strg: Attempt to copy more character bytes to the output string than allowed by the maximum
length byte in the string declaration

Chars_TO_Strg: The nul character (16#00) value was found in the input character byte array.

Strg_TO_Chars: Attempt to copy more character bytes to the output array than are allowed by the element
number limit

8.2.3.3

ASCII to Hex and Hex to ASCII conversions
Use the ATH (ASCII to hexadecimal) and HTA (hexadecimal to ASCII) instructions for
conversions between ASCII character bytes (characters 0 to 9 and uppercase A to F only)
and the corresponding 4-bit hexadecimal nibbles.

Table 8- 42
LAD / FBD

ATH instruction
Description
Converts ASCII characters into packed hexadecimal digits.

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8.2 String and character

Table 8- 43

Data types for the ATH instruction
Data Type

Description

Parameter type
IN

Variant

Pointer to ASCII character byte array

UInt

Number of ASCII character bytes to convert

RET_VAL

OUT

Word

Execution condition code

OUT

Variant

Pointer to the converted hexadecimal byte array

Conversion begins at the location specified by parameter IN and continues for N bytes. The
result is placed at the location specified by OUT. Only valid ASCII characters 0 to 9 and
uppercase A to F can be converted. Any other character will be converted to zero.
8-bit ASCII coded characters are converted to 4-bit hexadecimal nibbles. Two ASCII
characters can be stored in a single byte.
The IN and OUT parameters specify byte arrays and not hexadecimal String data. ASCII
characters are converted and placed in the hexadecimal output in the same order as they
are read. If there are an odd number of ASCII characters, then zeros are put in the rightmost nibble of the last converted hexadecimal digit.
Table 8- 44

ATH condition codes

RET_VAL (W#16#....)

Description

0000

No error

TRUE

0007

Invalid ATH input character

FALSE

Table 8- 45

ENO

Examples of ASCII-to-hexadecimal (ATH) conversion

IN character bytes

OUT value

ENO

'0123'

W#16#0123

TRUE

'123AFx1a23'

DW#16#123AF01023

FALSE

'a23'

W#16#A230

TRUE

Table 8- 46
LAD / FBD

HTA instruction
Description
Converts packed hexadecimal digits to their corresponding ASCII character bytes.

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8.2 String and character
Table 8- 47

Data types for the HTA instruction

Parameter and type

Data Type

Description

Variant

Pointer to input byte array

UInt

Number of bytes to convert (each input byte has two 4-bit nibbles and
produces 2N ASCII characters)

RET_VAL

OUT

Word

Execution condition code

OUT

Variant

Pointer to ASCII character byte array

Conversion begins at the location specified by parameter IN and continues for N bytes. Each
4-bit nibble converts to a single 8-bit ASCII character and produces 2N ASCII character
bytes of output. All 2N bytes of the output are written as ASCII characters 0 to 9 through
uppercase A to F. The parameter OUT specifies a byte array and not a string.
Each nibble of the hexadecimal byte is converted into a character in the same order as they
are read in (left-most nibble of a hexadecimal digit is converted first, followed by the rightmost nibble of that same byte).
Table 8- 48

Examples of hexadecimal -to- ASCII (HTA) conversion

IN value

OUT character bytes

ENO (ENO always TRUE after HTA execution)

W#16#0123

'0123'

TRUE

DW#16#123AF012

'123AF012'

TRUE

Table 8- 49

ATH and HTA condition codes

RET_VAL
(W#16#....)

Description

ENO

0000

No error

TRUE

0007

Invalid ATH input character: A character was found that was not an ASCII character 0- FALSE
9, lowercase a-f, or uppercase A-F

8101

Illegal or invalid input pointer, for example, an access to a DB that does not exist.

8120

Input string is an invalid format, i.e., max= 0, max=255, current>max, or grant length in FALSE
pointer < max

FALSE

8182

Input buffer is too small for N

FALSE

8151

Data type not allowed for input buffer

FALSE

8301

Illegal or invalid output pointer, for example, an access to a DB that does not exist.

FALSE

8320

Output string is an invalid format, i.e., max= 0, max=255, current>max, or grant length
in pointer < max

FALSE

8382

Output buffer is too small for N

FALSE

8351

Data type not allowed for output buffer

FALSE

8.2.4

String operation instructions
Your control program can use the following string and character instructions to create
messages for operator display and process logs.

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8.2 String and character

8.2.4.1
Table 8- 50

LEN
Length instruction

LAD / FBD

Description
LEN (length) provides the current length of the string IN at output OUT. An empty string has a length of
zero.

Table 8- 51

Data types for the parameters

Parameter and type

Data type

Description

String

Input string

OUT

Int, DInt, Real, LReal

Number of valid characters of IN string

Table 8- 52
ENO

ENO status
Condition

OUT

No invalid string condition

Valid string length

Current length of IN exceeds maximum length of IN

Current length is set to 0

Maximum length of IN does not fit within allocated memory range
Maximum length of IN is 255 (illegal length)

8.2.4.2
Table 8- 53

CONCAT
Concatenate strings instruction

LAD / FBD

Description
CONCAT (concatenate strings) joins string parameters IN1 and IN2 to form one string provided at OUT.
After concatenation, String IN1 is the left part and String IN2 is the right part of the combined string.

Table 8- 54

Data types for the parameters

Parameter and type

Data type

Description

IN1

String

Input string 1

IN2

String

Input string 2

OUT

String

Combined string (string 1 + string 2)

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8.2 String and character
Table 8- 55
ENO

ENO status
Condition

OUT

No errors detected

Valid characters

Resulting string after concatenation is larger than maximum length of OUT
string

Resulting string characters are
copied until the maximum length
of the OUT is reached

Current length of IN1 exceeds maximum length of IN1, current length of
IN2 exceeds maximum length of IN2, or current length of OUT exceeds
maximum length of OUT (invalid string)

Current length is set to 0

Maximum length of IN1, IN2 or OUT does not fit within allocated memory
range
Maximum length of IN1 or IN2 is 255, or the maximum length of OUT is 0
or 255

8.2.4.3
Table 8- 56
LAD / FBD

LEFT, RIGHT, and MID
Left, right and middle substring operations
Description
LEFT (Left substring) provides a substring made of the first L characters of string parameter IN.


If L is greater than the current length of the IN string, then the entire IN string is returned in OUT.



If an empty string is the input, then an empty string is returned in OUT.

MID (Middle substring) provides the middle part of a string. The middle substring is L characters long
and starts at character position P (inclusive).
If the sum of L and P exceeds the current length of the string parameter IN, then a substring is returned
that starts at character position P and continues to the end of the IN string.

RIGHT (Right substring) provides the last L characters of a string.


If L is greater than the current length of the IN string, then the entire IN string is returned in
parameter OUT.



If an empty string is the input, then an empty string is returned in OUT.

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8.2 String and character
Table 8- 57

Data types for the parameters

Parameter and type

Data type

Description

String

Input string

Int

Length of the substring to be created:


LEFT uses the left-most characters number of characters in the
string



RIGHT uses the right-most number of characters in the string



MID uses the number of characters starting at position P within
the string

Int

MID only: Position of first substring character to be copied

OUT

String

Output string

P= 1, for the initial character position of the IN string

Table 8- 58

ENO status

ENO

Condition

OUT

No errors detected

Valid characters



L or P is less than or equal to 0



P is greater than maximum length of IN



Current length of IN exceeds maximum length of IN, or current length
of OUT exceeds maximum length of OUT



Maximum length of IN or OUT does not fit within allocated memory



Maximum length of IN or OUT is 0 or 255

Current length is set to 0

Substring length (L) to be copied is larger than maximum length of OUT
string.

Characters are copied until the
maximum length of OUT is
reached

MID only: L or P is less than or equal to 0

Current length is set to 0

MID only: P is greater than maximum length of IN
Current length of IN1 exceeds maximum length of IN1, or current length of
IN2 exceeds maximum length of IN2 (invalid string)

Current length is set to 0

Maximum length of IN1, IN2 or OUT does not fit within allocated memory
range
Maximum length of IN1, IN2 or OUT is 0 or 255 (illegal length)

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8.2 String and character

8.2.4.4
Table 8- 59

DELETE
Delete substring instruction

LAD / FBD

Description
Deletes L characters from string IN. Character deletion starts at character position P (inclusive), and the
remaining substring is provided at parameter OUT.

Table 8- 60



If L is equal to zero, then the input string is returned in OUT.



If the sum of L and P is greater than the length of the input string, then the string is deleted to the
end.

Data types for the parameters

Parameter and type

Data type

Description

String

Input string

Int

Number of characters to be deleted

Int

Position of the first character to be deleted: The first character of
the IN string is position number 1

OUT

String

Output string

Table 8- 61
ENO

ENO status
Condition

OUT

No errors detected

Valid characters

P is greater than current length of IN

IN is copied to OUT with no
characters deleted

Resulting string after characters are deleted is larger than maximum length Resulting string characters are
of OUT string
copied until the maximum length
of OUT is reached
L is less than 0, or P is less than or equal to 0

Current length is set to 0

Current length of IN exceeds maximum length of IN, or current length of
OUT exceeds maximum length of OUT
Maximum length of IN or OUT does not fit within allocated memory
Maximum length of IN or OUT is 0 or 255

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8.2 String and character

8.2.4.5
Table 8- 62

INSERT
Insert substring instruction

LAD / FBD

Description
Inserts string IN2 into string IN1. Insertion begins after the character at position P.

Table 8- 63

Data types for the parameters

Parameter and type

Data type

Description

IN1

String

Input string 1

IN2

String

Input string 2

Int

Last character position in string IN1 before the insertion point for
string IN2

OUT

String

The first character of string IN1 is position number 1.

Table 8- 64

Result string

ENO status

ENO

Condition

OUT

No errors detected

Valid characters

P is greater than length of IN1

IN2 is concatenated with IN1
immediately following the last IN1
character

P is less than 0

Current length is set to 0

Resulting string after insertion is larger than maximum length of
OUT string

Resulting string characters are copied
until the maximum length of OUT is
reached

Current length of IN1 exceeds maximum length of IN1, current
length of IN2 exceeds maximum length of IN2, or current length of
OUT exceeds maximum length of OUT (invalid string)

Current length is set to 0

Maximum length of IN1, IN2 or OUT does not fit within allocated
memory range
Maximum length of IN1 or IN2 is 255, or maximum length of OUT is
0 or 255

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8.2 String and character

8.2.4.6
Table 8- 65

REPLACE
Replace substring instruction

LAD / FBD

Description
Replaces L characters in the string parameter IN1. Replacement starts at string IN1 character position P
(inclusive), with replacement characters coming from the string parameter IN2.

Table 8- 66

Data types for the parameters

Parameter and type

Data type

Description

IN1

String

Input string

IN2

String

String of replacement characters

Int

Number of characters to replace

Int

Position of first character to be replaced

OUT

String

Result string

If parameter L is equal to zero, then the string IN2 is inserted at position P of string IN1
without deleting any characters from string IN1.
If P is equal to one, then the first L characters of string IN1 are replaced with string IN2
characters.
Table 8- 67

ENO status

ENO

Condition

OUT

No errors detected

Valid characters

P is greater than length of IN1

IN2 is concatenated with IN1
immediately following the last IN1
character

P points within IN1, but fewer than L characters remain in IN1

IN2 replaces the end characters of IN1
beginning at position P

Resulting string after replacement is larger than maximum length of
OUT string

Resulting string characters are copied
until the maximum length of OUT is
reached

Maximum length of IN1 is 0

IN2 characters are copied to OUT

L is less than 0, or P is less than or equal to 0

Current length is set to 0

Current length of IN1 exceeds maximum length of IN1, current
length of IN2 exceeds maximum length of IN2, or current length of
OUT exceeds maximum length of OUT
Maximum length of IN1, IN2 or OUT does not fit within allocated
memory range
Maximum length of IN1 or IN2 is 255, or maximum length of OUT is
0 or 255

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8.2 String and character

8.2.4.7
Table 8- 68

FIND
Find substring instruction

LAD / FBD

Description
Provides the character position of the substring specified by IN2 within the string IN1. The search starts
on the left. The character position of the first occurrence of IN2 string is returned at OUT. If the string
IN2 is not found in the string IN1, then zero is returned.

Table 8- 69

Data types for the parameters

Parameter and type

Data type

Description

IN1

String

Search inside this string

IN2

String

Search for this string

OUT

Int

Character position in string IN1 of the first search match

Table 8- 70
ENO

ENO status
Condition

OUT

No errors detected

Valid character position

IN2 is larger than IN1

Character position is set to 0

Current length of IN1 exceeds maximum length of IN1, or current length
of IN2 exceeds maximum length of IN2 (invalid string)
Maximum length of IN1 or IN2 does not fit within allocated memory
range
Maximum length of IN1 or IN2 is 255

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8.3 Distributed I/O

8.3

Distributed I/O

8.3.1

RDREC and WRREC
You can use the RDREC (Read record) and WRREC (Write record) instructions with
PROFINET, PROFIBUS, and GPRS.

Table 8- 71
LAD / FBD

RDREC and WRREC instructions
Description
Use the RDREC instruction to read a data record with the number INDEX from the
component addressed by the ID, such as a central rack or a distributed component
(PROFIBUS DP or PROFINET IO). Assign the maximum number of bytes to read
in MLEN. The selected length of the target area RECORD should have at least the
length of MLEN bytes.

Use the WRREC instruction to transfer a data RECORD with the record number
INDEX to a DP slave/PROFINET IO device component addressed by ID, such as a
module in the central rack or a distributed component (PROFIBUS DP or
PROFINET IO).
Assign the byte length of the data record to be transmitted. The selected length of
the source area RECORD should, therefore, have at least the length of LEN bytes.

STEP 7 automatically creates the DB when you insert the instruction.

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8.3 Distributed I/O
Table 8- 72

RDREC and WRREC data types for the parameters

Parameter and type

Data type

Description

REQ

Bool

REQ = 1: Transfer data record

HW_IO (Word)

Logical address of the DP slave/PROFINET IO component
(module or submodule):


For an output module, bit 15 must be set (for example, for
address 5: ID:= DW#16#8005).

For a combination module, the smaller of the two addresses
should be specified.
Note: The device ID can be determined in one of two ways:




By making the following "Network view" selections:
–

Device (gray box)

–

"Properties" of the device

–

"Hardware identifier"
Note: Not all devices display their Hardware identifiers,
however.

By making the following "Project tree" menu selections:
–

PLC tags

–

Default tag table

–

System constants tab

All configured device Hardware identifiers are displayed.
INDEX

Byte, Word, USInt,
UInt, SInt, Int, DInt

Data record number

MLEN

Byte, USInt, UInt

Maximum length in bytes of the data record information to be
fetched (RDREC)

VALID

OUT

Bool

New data record was received and valid (RDREC). The VALID
bit is TRUE for one scan, after the last request was completed
with no error.

DONE

OUT

Bool

Data record was transferred (WRREC). The DONE bit is TRUE
for one scan, after the last request was completed with no error.

BUSY

OUT

Bool



BUSY = 1: The read (RDREC) or write (WRREC) process is
not yet terminated.



BUSY = 0: Data record transmission is completed.

ERROR

OUT

Bool

ERROR = 1: A read (RDREC) or write (WRREC) error has
occurred. The ERROR bit is TRUE for one scan, after the last
request was terminated with an error. The error code value at
the STATUS parameter is valid only during the single scan
where ERROR = TRUE.

STATUS

OUT

DWord

Block status or error information

LEN

OUT (RDREC)
IN (WRREC)

UInt



Length of the fetched data record information (RDREC)



Maximum byte length of the data record to be transferred
(WRREC)

IN_OUT

Variant



Target area for the fetched data record (RDREC)



Data record (WRREC)

RECORD

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8.3 Distributed I/O
The RDREC and WRREC instructions operate asynchronously, that is, processing covers
multiple instruction calls. Start the job by calling RDREC or WRREC with REQ = 1.
The job status is displayed via output parameter BUSY and the two central bytes of output
parameter STATUS. The transfer of the data record is complete when the output parameter
BUSY has the value FALSE
TRUE (only for one scan) on the output parameter VALID (RDREC) or DONE (WRREC)
verifies that the data record has been successfully transferred into the target area RECORD
(RDREC) or to the target device (WRREC). In the case of the RDREC, the output parameter
LEN contains the length of the fetched data in bytes.
The output parameter ERROR (only for one scan when ERROR = TRUE) indicates that a
data record transmission error has occurred. In this case, the output parameter STATUS
(only for the one scan when ERROR = TRUE) contains the error information.
Data records are defined by the hardware device manufacturer. Refer to the hardware
manufacturer's device documentation for details about a data record.
Note
If a DPV1 slave is configured via GSD file (GSD rev. 3 and higher) and the DP interface of
the DP master is set to "S7 compatible", then you may not read any data records from the
I/O modules in the user program with "RDREC" or write to the I/O modules with "WRREC".
In this case, the DP master addresses the wrong slot (configured slot + 3).
Remedy: set the interface of the DP master to "DPV1".
Note
The interfaces of the "RDREC" and "WRREC" instructions are identical to the "RDREC" and
"WRREC" FBs defined in "PROFIBUS Guideline PROFIBUS Communication and Proxy
Function Blocks according to IEC 61131-3".
Note
If you use "RDREC" or "WRREC" to read or write a data record for PROFINET IO, then
negative values in the INDEX, MLEN, and LEN parameters will be interpreted as an
unsigned 16-bit integer.

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8.3 Distributed I/O

8.3.2

RALRM
You can use the RALRM (Read alarm) instruction with PROFINET, PROFIBUS, and GPRS.

Table 8- 73
LAD / FBD

RALRM instruction
Description
Use the RALRM (read alarm) instruction to read diagnostic interrupt information from a DP slave or
PROFINET I/O device.
The information in the output parameters contains the start information of the called OB as well as
information of the interrupt source.
Call RALRM only within the interrupt OB that was started by the CPU operating system as a response to
the peripheral I/O interrupt that you want to examine.

STEP 7 automatically creates the DB when you insert the instruction.

Table 8- 74

Data types for the parameters

Parameter and type

Data type

Description

MODE

Byte, USInt, SInt, Int

Operating mode

F_ID

HW_IO (Word)

Logical start address of the component (module) from which interrupts
are to be received
Note: The device ID can be determined in one of two ways:




MLEN

Byte, USInt, UInt

By making the following "Network view" selections:
–

Device (gray box)

–

"Properties" of the device

–

"Hardware identifier"
Note: Not all devices display their Hardware identifiers, however.

By making the following "Project tree" menu selections:
–

PLC tags

–

Default tag table

–

System constants tab

–

All configured device Hardware identifiers are displayed.

Maximum length in bytes of the data interrupt information to be
received

NEW

OUT

Bool

A new interrupt was received.

STATUS

OUT

DWord

Error code of the DP Master

OUT

HW_IO (Word)

Logical start address of the component (module) from which an
interrupt was received. Bit 15 contains the I/O ID:


0 for an input address

 1 for and output address
Note: Refer to the F_ID parameter for an explanation of how to
determine the device ID.
LEN

OUT

DWord, UInt, UDInt,
DInt, Real, LReal

Length of the received interrupt information

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8.3 Distributed I/O

Parameter and type

Data type

Description

TINFO

IN_OUT

Variant

Task information: Target range for OB start and management
information

AINFO

IN_OUT

Variant

Interrupt information: Target area for header information and additional
interrupt information. For AINFO, provide a length of at least the MLEN
bytes.

Note
If you call "RALRM" in an OB whose start event is not an I/O interrupt, the instruction will
provide correspondingly reduced information in its outputs.
Make sure to use different instance DBs when you call "RALRM" in different OBs. If you
evaluate data resulting from a "RALRM" call outside of the associated interrupt OB, you
should use a separate instance DB per OB start event.
Note
The interface of the "RALRM" instruction is identical to the "RALRM" FB defined in
"PROFIBUS Guideline PROFIBUS Communication and Proxy Function Blocks according to
IEC 61131-3".

Calling RALRM
You can call the RALRM instruction in three different operating modes (MODE).
Table 8- 75

RALRM instruction operating modes

MODE

Description

Shows the component that triggered the interrupt in the output parameter ID and sets the output
parameter NEW to TRUE.

Describes all output parameters, independent of the interrupt triggering component.

Checks whether the component specified in input parameter F_ID has triggered the interrupt.


If not, NEW = FALSE



If yes, NEW = TRUE, and all other outputs parameters are described.

Note
If you assign a destination area for TINFO or AINFO that is too short, RALRM cannot return
the full information. Refer to the online information system of STEP 7 for immediate access
to information on how to interpret the TINFO and AINFO returned buffers.

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8.3 Distributed I/O

8.3.3

STATUS parameter for RDREC, WRREC, and RALRM
The output parameter STATUS contains error information that is interpreted as ARRAY[1...4]
OF BYTE, with the following structure:

Table 8- 76

STATUS output array

Array element

Name

Description

STATUS[1]

Function_Num



B#16#00, if no error



Function ID from DPV1-PDU: If an error occurs, B#16#80 is OR'ed (for read
data record: B#16#DE; for write data record: B#16#DF). If no DPV1 protocol
element is used, then B#16#C0 will be output.

STATUS[2]

Error_Decode

STATUS[3]

Error_Code_1

Error ID

STATUS[4]

Error_Code_2

Manufacturer-specific error ID expansion

Table 8- 77

Location of the error ID

STATUS[2] values

Error_decode
(B#16#....)

Source

Description

00 to 7F

CPU

No error or no warning

DPV1

Error according to IEC 61158-6

81 to 8F

CPU

B#16#8x shows an error in the "xth" call parameter of the instruction.

FE, FF

DP Profile

Profile-specific error

Table 8- 78

STATUS[3] values

Error_decode
(B#16#....)

Error_code_1
(B#16#....)

Explanation (DVP1)

Description

Reserved, reject

Initial call; no active data record transfer

Reserved, reject

Initial call; data record transfer has started

Reserved, reject

Intermediate call; data record transfer already active

Reserved, pass

Invalid logical start address

No error, no warning

Reserved, pass

Illegal type for Variant pointer

Reserved, pass

The DP component addressed via ID or F_ID is not
configured.

The "RALRM (Page 237)" cannot supply the OB start
information, management information, header
information, or additional interrupt information.
For OBs 4x, 55, 56, 57, 82, and 83, you can use the
"DPNRM_DG (Page 244)" instruction to read the current
diagnostics message frame of the relevant DP slave
asynchronously (address information from OB start
information).

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Error_decode
(B#16#....)

Error_code_1
(B#16#....)

Explanation (DVP1)

Description

Read error

Negative acknowledgement while reading from the
module

Write error

Negative acknowledgement while writing to the module

Module failure

DP protocol error at layer 2 (for example, slave failure or
bus problems)

Reserved, pass



PROFIBUS DP: DP protocol error with Direct-DataLink-Mapper or User-Interface/User



PROFINET IO: General CM error

Reserved, pass

Communication on the communication bus disrupted

Reserved, pass

DP slave or modules is occupied (temporary error).

Version conflict

DP slave or module reports non-compatible versions.

Feature not supported

Feature not supported by DP slave or module

AA to AF

User specific

DP slave or module reports a manufacturer-specific error
in its application. Please check the documentation from
the manufacturer of the DP slave or module.

Invalid index

Data record not known in module; illegal data record
number ≥ 256

Write length error

The length information in the RECORD parameter is
incorrect.


With "RALRM": Length error in AINFO
Note: Refer to the online information system of
STEP 7 for immediate access to information on how
to interpret the "AINFO" returned buffers.



With "RDREC (Page 234)" and "WRREC
(Page 234)": Length error in "MLEN"

Invalid slot

The configured slot is not occupied.

Type conflict

Actual module type does not match specified module
type.

Invalid area

DP slave or module reports access to an invalid area.

Status conflict

DP slave or module not ready

Access denied

DP slave or module denies access.

Invalid range

DP slave or module reports an invalid range for a
parameter or value.

Invalid parameter

DP slave or module reports an invalid parameter.

Invalid type

BA to BF

User specific

DP slave or module reports an invalid type:


With "RDREC (Page 234)": Buffer too small (subsets
cannot be read)



With "WRREC (Page 234)": Buffer too small (subsets
cannot be written)

DP slave or module reports a manufacturer-specific error
when accessing. Please check the documentation from
the manufacturer of the DP slave or module.

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Error_decode
(B#16#....)

Error_code_1
(B#16#....)

Explanation (DVP1)

Description

Read constraint conflict 



With "RDREC (Page 234)": The module routes the
data record, but either no data is present or the data
can only be read when the CPU is in STOP mode.
Note: If data can only be read when the CPU is in
STOP mode, no evaluation by the user program is
possible. In this case, you can only read the data
online with a PG/PC.

Write constraint conflict The data of the previous write request to the module for
the same data record has not yet been processed by the
module.

Resource busy

The module is currently processing the maximum
possible number of jobs for a CPU.

Resource unavailable

The required operating resources are currently occupied.

Internal temporary error. Job could not be carried out.
Repeat the job. If this error occurs often, check your
installation for sources of electrical interference.

DP slave or module not available

Data record transfer was cancelled due to priority class
cancellation.

Job aborted due to warm or cold restart on the DP
master.

C8 to CF

DP slave or module reports a manufacturer-specific
resource error. Please check the documentation from the
manufacturer of the DP slave or module.

Dx
81

With "WRREC (Page 234)": The data can only be
written when the CPU is in STOP mode.
Note: This means that data cannot be written by the
user program. You can only write the data online with
a PG/PC.

User specific

DP Slave specific. Refer to the description of the DP
Slave.

00 to FF

Error in the initial call parameter (with "RALRM
(Page 237)": MODE)

Illegal operating mode

00 to FF

Error in the second call parameter

00 to FF

Error in the eighth call parameter (with "RALRM
(Page 237)": TINFO)
Note: Refer to the online information system of STEP 7
for immediate access to information on how to interpret
the "TINFO" returned buffers.

Wrong syntax ID

Quantity structure exceeded or destination area too small

Wrong range ID

DB/DI number out of user range

DB/DI number is NULL for area ID DB/DI, or specified
DB/DI does not exist.

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Error_decode
(B#16#....)

Error_code_1
(B#16#....)

00 to FF

Explanation (DVP1)

Description
Error in the ninth call parameter (with "RALRM
(Page 237)": AINFO)
Note: Refer to the online information system of STEP 7
for immediate access to information on how to interpret
the "AINFO" returned buffers.

Wrong syntax ID

Quantity structure exceeded or destination area too small

Wrong range ID

DB/DI number out of user range

DB/DI number is NULL for area ID DB/DI, or specified
DB/DI does not exist.

00 to FF

Error in the 10th call parameter

00 to FF

Error in the 15th call parameter

FE, FF

00 to FF

Profile-specific error

Array element STATUS[4]
With DPV1 errors, the DP Master passes on STATUS[4] to the CPU and to the instruction.
Without a DPV1 error, this value is set to 0, with the following exceptions for the RDREC:
● STATUS[4] contains the target area length from RECORD, if MLEN > the destination
area length from RECORD.
● STATUS[4]=MLEN, if the actual data record length < MLEN < the destination area length
from RECORD.
● STATUS[4]=0, if STATUS[4] > 255; would have to be set
In PROFINET IO, STATUS[4] has the value 0.

8.3.4

DPRD_DAT and DPWR_DAT
You can use the DPRD_DAT (Read consistent data) and DPWR_DAT (Write consistent
data) instructions with PROFINET, PROFIBUS, and GPRS.

Table 8- 79
LAD / FBD

DPRD_DAT and DPWR_DAT instructions
Description
Use the DPRD_DAT instruction to read the consistent data of a DP standard slave/PROFINET IO
device. If no errors occur during the data transfer, the data read is entered into the target area set
up by the RECORD parameter. The target area must have the same length as you configured
with STEP 7 for the selected module. When you call the DPRD_DAT instruction, you can only
access the data of one module / DP identification under the configured start address.
Use the DPWR_DAT instruction to transfer the data in RECORD consistently to the addressed
DP standard slave/PROFINET IO device. The source area must have the same length as you
configured with STEP 7 for the selected module.

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The CPU supports up to 64 bytes of consistent data. For consistent data areas greater than
64 bytes, the DPRD_DAT and DPWR_DAT instructions must be used. If required, these
instructions can be used for data areas of 1 byte or greater. If access is rejected, error code
W#16#8090 will result.
Note
If you are using the DPRD_DAT and DPWR_DAT instructions with consistent data, you must
remove this consistent data from the process-image automatic update. Refer to "PLC
concepts: Execution of the user program" (Page 61) for more information.

Table 8- 80

Data types for the parameters

Parameter and type

Data type

Description

LADDR

HW_IO (Word)



Configured start address from the "I" area of the module from which
the data will be read (DPRD_DAT)

Configured start address from the process image output area of the
module to which the data will be written (DPWR_DAT)
Addresses have to be entered in hexadecimal format (for example, an
input or output address of 100 means: LADDR:=W#16#64).


RECORD

OUT

Variant

Destination area for the user data that were read (DPRD_DAT) or source
area for the user data to be written (DPWR_DAT). This must be exactly
as large as you configured for the selected module with STEP 7. Only the
data type Byte is permitted.

RET_VAL

OUT

Int

If an error occurs while the function is active, the return value contains an
error code.

DPRD_DAT operations
The destination area must have the same length as configured for the selected module with
STEP 7. If no error occurs during the data transfer, the data that have been read are entered
into the destination area identified by RECORD.
If you read from a DP standard slave with a modular design or with several DP identifiers,
you can only access the data of one module/DP identifier for each DPRD_DAT instruction
call, specifying the configured start address.

DPWR_DAT operations
You transfer the data in RECORD consistently to the addressed DP standard
slave/PROFINET IO. The data is transferred synchronously, that is, the write process is
completed when the instruction is completed.
The source area must have the same length as you configured for the selected module with
STEP 7.
If the DP standard slave has a modular design, you can only access one module of the DP
slave.

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Table 8- 81

DPRD_DAT and DPWR_DAT error codes

Error code

Description

0000

No error occurred

808x

System error with external DP interface module

8090

One of the following cases apply:


You have not configured a module for the specified logical base address.



You have ignored the restriction concerning the length of consistent data.



You have not entered the start address in the LADDR parameter in hexadecimal format.

8092

A type other than Byte is specified in the Any reference.

8093

No DP module/PROFINET IO device from which you can read (DPRD_DAT) or to which you can
write (DPWR_DAT) consistent data exists at the logical address specified in LADDR.

80A0

Access error detected while the I/O devices were being accessed (DPRD_DAT).

80A1

Access error detected while the I/O devices were being accessed (DPWR_DAT).

80B0

Slave failure on external DP interface module

80B1

The length of the specified destination (DPRD_DAT) or source (DPWR_DAT) area is not identical to
the user data length configured with STEP 7 Basic.

80B2, 80B3, 80C2,
80Fx

System error with external DP interface module (DPRD_DAT) and (DPWR_DAT)

87xy, 808x

System error with external DP interface module (DPRD_DAT)

85xy

System error with external DP interface module (DPWR_DAT)

80C0

The data have not yet been read by the module (DPRD_DAT).

80C1

The data of the previous write job on the module have not yet been processed by the module
(DPWR_DAT).

8xyy1

General error information

Refer to "Extended instructions, Distributed I/O: Error information for RDREC, WRREC, and
RALRM" (Page 239) for more information on general error codes.
Note
If you access DPV1 slaves, error information from these slaves can be forwarded from the
DP master to the instruction.

8.3.5

DPNRM_DG
You can use the DPNRM_DG (Read diagnostic data) instruction with PROFIBUS.

Table 8- 82
LAD / FBD

DPNRM_DG instruction
Description
Use the DPNRM_DG instruction to read the current diagnostic data of a DP slave in the format specified by
EN 50 170 Volume 2, PROFIBUS. The data that has been read is entered in the destination area indicated
by RECORD following error-free data transfer.

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Table 8- 83

DPNRM_DG instruction data types for the parameters

Parameter and type

Data type

Description

REQ

Bool

REQ=1: Read request

LADDR

HW_DPSLAVE

Configured diagnostic address of the DP slave: Must be the address of
the station and not for the I/O device. Select the station (and not the
image of the device) in the "Network" view of the "Device configuration"
to determine the diagnostic address.
Enter the addresses in hexadecimal format. For example, diagnostic
address 1022 means LADDR:=W#16#3FE.

RET_VAL

OUT

Int

If an error occurs while the function is active, the return value contains
an error code. If no error occurs, the length of the data actually
transferred is entered in RET_VAL.

RECORD

OUT

Variant

Destination area for the diagnostic data that were read. Only the Byte
data type is permitted. The minimum length of the data record to be
read or the destination area is 6. The maximum length of the data
record to be sent is 240.
Standard slaves can provide more than 240 bytes of diagnostic data up
to a maximum of 244 bytes. In this case, the first 240 bytes are
transferred to the destination area, and the overflow bit is set in the
data.

BUSY

OUT

Bool

BUSY=1: The read job is not yet completed

You start the read job by assigning 1 to the input parameter REQ in the DPNRM_DG
instruction call. The read job is executed asynchronously, in other words, it requires several
DPNRM_DG instruction calls. The status of the job is indicated by the output parameters
RET_VAL and BUSY.
Table 8- 84

Slave diagnostic data structure

Byte

Description

Station status 1

Station status 2

Station status 3

Master station number

Vendor ID (high byte)

Vendor ID (low byte)

6 ...

Additional slave-specific diagnostic information

Table 8- 85

DPNRM_DG instruction error codes

Error code

Description

Restriction

0000

No error

7000

First call with REQ=0: No data transfer active; BUSY has the value 0.

7001

First call with REQ =1: No data transfer active; BUSY has the value 1.

Distributed I/Os

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Error code

Description

Restriction

7002

Interim call (REQ irrelevant): Data transfer already active; BUSY has the
value 1.

Distributed I/Os

8090

Specified logical base address invalid: There is no base address.

8092

The type specified in the Any reference is not Byte.

8093



This instruction is not permitted for the module specified by LADDR
(S7-DP modules for S7-1200 are permitted).



LADDR specifies the I/O device instead of specifying the station. Select
the station (and not the image of the device) in the "Network" view of
the "Device configuration" to determine the diagnostic address for
LADDR.



DP protocol error at layer 2 (for example, slave failure or bus problems) Distributed I/Os



For ET200S, data record cannot be read in DPV0 mode.

80A2

80A3

DP protocol error with user interface/user

Distributed I/Os

80A4

Communication problem on the communication bus

The error occurs between the
CPU and the external DP
interface module.

80B0



The instruction is not possible for module type.



The module does not recognize the data record.



Data record number 241 is not permitted.

80B1

The length specified in the RECORD parameter is incorrect.

Specified length > record
length

80B2

The configured slot is not occupied.

80B3

Actual module type does not match the required module type.

80C0

There is no diagnostic information.

80C1

The data of the previous write job for the same data record on the module
have not yet been processed by the module.

80C2

The module is currently processing the maximum possible number of jobs
for a CPU.

80C3

The required resources (memory, etc.) are currently occupied.

80C4

Internal temporary error. The job could not be processed.
Repeat the job. If this error occurs frequently, check your system for
electrical disturbance sources.

80C5

Distributed I/Os not available

Distributed I/Os

80C6

Data record transfer was stopped due to a priority class abort (restart or
background)

Distributed I/Os

8xyy1

General error codes

Refer to "Extended instructions, Distributed I/O: Error information for RDREC, WRREC, and
RALRM" (Page 239) for more information on general error codes.

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8.4 Interrupts

8.4

Interrupts

8.4.1

Attach and detach instructions
You can activate and deactivate interrupt event-driven subprograms with the ATTACH and
DETACH instructions.

Table 8- 86

ATTACH and DETACH instructions

LAD / FBD

Description
ATTACH enables interrupt OB subprogram execution for a hardware interrupt event.

DETACH disables interrupt OB subprogram execution for a hardware interrupt event.

Table 8- 87

Data types for the parameters

Parameter and type

Data type

Description

OB_NR

OB_ATT

Organization block identifier: Select from the available hardware
interrupt OBs that were created using the "Add new block" feature.
Double-click on the parameter field, then click on the helper icon to
see the available OBs.

EVENT

EVENT_ATT

Event identifier: Select from the available hardware interrupt events
that were enabled in PLC device configuration for digital inputs or
high-speed counters. Double-click on the parameter field, then click
on the helper icon to see the available events.

ADD
(ATTACH only)

Bool



ADD = 0 (default): This event replaces all previous event
attachments for this OB.



ADD = 1: This event is added to previous event attachments for
this OB.

RET_VAL

OUT

Int

Execution condition code

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8.4 Interrupts

Hardware interrupt events
The following hardware interrupt events are supported by the CPU:
● Rising edge events (all built-in CPU digital inputs and SB digital inputs)
– A rising edge occurs when the digital input transitions from OFF to ON as a response
to a change in the signal from a field device connected to the input.
● Falling edge events (all built-in CPU digital inputs and SB digital inputs)
– A falling edge occurs when the digital input transitions from ON to OFF.
● High-speed counter (HSC) current value = reference value (CV = RV) events (HSC 1
through 6)
– A CV = RV interrupt for a HSC is generated when the current count transitions from an
adjacent value to the value that exactly matches a reference value that was previously
established.
● HSC direction changed events (HSC 1 through 6)
– A direction changed event occurs when the HSC is detected to change from
increasing to decreasing, or from decreasing to increasing.
● HSC external reset events (HSC 1 through 6)
– Certain HSC modes allow the assignment of a digital input as an external reset that is
used to reset the HSC count value to zero. An external reset event occurs for such a
HSC, when this input transitions from OFF to ON.

Enabling hardware interrupt events in the device configuration
Hardware interrupts must be enabled during the device configuration. You must check the
enable-event box in the device configuration for a digital input channel or a HSC, if you want
to attach this event during configuration or run time.
Check box options within the PLC device configuration:
● Digital input
– Enable rising edge detection
– Enable falling edge detection
● High-speed counter (HSC)
– Enable this high-speed counter for use
– Generate interrupt for counter value equals reference value count
– Generate interrupt for external reset event
– Generate interrupt for direction change event

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8.4 Interrupts

Adding new hardware interrupt OB code blocks to your program
By default, no OB is attached to an event when the event is first enabled. This is indicated by
the "HW interrupt:" device configuration "" label. Only hardware-interrupt
OBs can be attached to a hardware interrupt event. All existing hardware-interrupt OBs
appear in the "HW interrupt:" drop-down list. If no OB is listed, then you must create an OB
of type "Hardware interrupt" as follows. Under the project tree "Program blocks" branch:
1. Double-click "Add new block", select "Organization block (OB)" and choose "Hardware
interrupt".
2. Optionally, you can rename the OB, select the programming language (LAD or FBD), and
select the block number (switch to manual and choose a different block number than that
suggested).
3. Edit the OB and add the programmed reaction that you want to execute when the event
occurs. You can call FCs and FBs from this OB, to a nesting depth of four.

OB_NR parameter
All existing hardware-interrupt OB names appear in the device configuration "HW interrupt:"
drop-down list and in the ATTACH / DETACH parameter OB_NR drop-list.

EVENT parameter
When a hardware interrupt event is enabled, a unique default event name is assigned to this
particular event. You can change this event name by editing the "Event name:" edit box, but
it must be a unique name. These event names become tag names in the "Constants" tag
table, and appear on the EVENT parameter drop-down list for the ATTACH and DETACH
instruction boxes. The value of the tag is an internal number used to identify the event.

General operation
Each hardware event can be attached to a hardware-interrupt OB which will be queued for
execution when the hardware interrupt event occurs. The OB-event attachment can occur at
configuration time or at run time.
You have the option to attach or detach an OB to an enabled event at configuration time. To
attach an OB to an event at configuration time, you must use the "HW interrupt:" drop-down
list (click on the down arrow on the right) and select an OB from the list of available
hardware-interrupt OBs. Select the appropriate OB name from this list, or select "" to remove the attachment.
You can also attach or detach an enabled hardware interrupt event during run time. Use the
ATTACH or DETACH program instructions during run time (multiple times if you wish) to
attach or detach an enabled interrupt event to the appropriate OB. If no OB is currently
attached (either from a "" selection in device configuration, or as a result of
executing a DETACH instruction), the enabled hardware interrupt event is ignored.

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8.4 Interrupts

DETACH operation
Use the DETACH instruction to detach either a particular event or all events from a particular
OB. If an EVENT is specified, then only this one event is detached from the specified
OB_NR; any other events currently attached to this OB_NR will remain attached. If no
EVENT is specified, then all events currently attached to OB_NR will be detached.

Condition codes
Table 8- 88

Condition codes

RET_VAL (W#16#....)

Description

0000

No error

0001

Nothing to Detach (DETACH only)

8090

OB does not exist

8091

OB is wrong type

8093

Event does not exist

8.4.2

Cyclic interrupts

8.4.2.1

SET_CINT (Set cyclic interrupt)

Table 8- 89

ENO

SET_CINT (Set cyclic interrupt instruction)

LAD / FBD

Description
Set the specified interrupt OB to begin cyclic execution that interrupts the program scan.

Table 8- 90

Data types for the parameters

Parameter and type
OB_NR

Data type

Description

OB_CYCLIC

OB number (accepts symbolic name)

CYCLE

UDInt

Time interval, in microseconds

PHASE

UDInt

Phase shift, in microseconds

RET_VAL

OUT

Int

Execution condition code

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8.4 Interrupts
Time parameter examples:
● If the CYCLE time = 100 us, then the interrupt OB referenced by OB_NR interrupts the
cyclic program scan every 100 us. The interrupt OB executes and then returns execution
control to the program scan, at the point of interruption.
● If the CYCLE time = 0, then the interrupt event is deactivated and the interrupt OB is not
executed.
● The PHASE (phase shift) time is a specified delay time that occurs before the CYCLE
time interval begins. You can use the phase shift to control the execution timing of lower
priority OBs.
If lower and higher priority OBs are called in the same time interval, the lower priority OB is
only called after the higher priority OB has finished processing. The execution start time for
the low priority OB can shift depending on the processing time of higher priority OBs.
2%FDOOZLWKRXWSKDVHVKLIW
581
W

2%
+LJKHUSULRULW\

2%
ORZSULRULW\

If you want to start the execution of a lower priority OB on a fixed time cycle, then phase shift
time should be greater then the processing time of higher priority OBs.
2%FDOOZLWKSKDVHVKLIW
581
W

2%
+LJKHUSULRULW\

W
2%
ORZSULRULW\
3KDVHVKLIW

Table 8- 91

Condition codes

RET_VAL (W#16#....)

Description

0000

No error

8090

OB does not exist or is of wrong type

8091

Invalid cycle time

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8.4.2.2
Table 8- 92

RET_VAL (W#16#....)

Description

8092

Invalid phase shift time

80B2

OB has no attached event

QRY_CINT (Query cyclic interrupt)
QRY_CINT (Query cyclic interrupt)

LAD / FBD

Description
Get parameter and execution status from a cyclic interrupt OB. The values that are
returned existed at the time QRY_CINT was executed.

Table 8- 93

Data types for the parameters

Parameter and type

Data type

Description

OB_NR

OB_CYCLIC

OB number (accepts symbolic name like OB_MyOBName)

RET_VAL

OUT

Int

Execution condition code

CYCLE

OUT

UDInt

Time interval, in microseconds

PHASE

OUT

UDInt

Phase shift, in microseconds

STATUS

OUT

Word

Cyclic interrupt status code:

Table 8- 94



Bits 0 to 4, see the STATUS table below



Other bits, always 0

STATUS parameter

Bit

Value

Description

During CPU RUN

1
2
4

During startup

The interrupt is enabled.

Interrupt is disabled via the DIS_IRT instruction.

The interrupt is not active or has elapsed.

The interrupt is active.

The OB identified by OB_NR does not exist.

The OB identified by OB_NR exists.

Other Bits

Always 0

If an error occurs, RET_VAL displays the appropriate error code and the parameter STATUS
= 0.

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Table 8- 95

8.4.3

RET_VAL parameter

RET_VAL (W#16#....)

Description

0000

No error

8090

OB does not exist or is of wrong type.

80B2

OB has no attached event.

Time delay interrupts
You can start and cancel time delay interrupt processing with the SRT_DINT and CAN_DINT
instructions, or query the interrupt status with the QRY_DINT instruction. Each time delay
interrupt is a one-time event that occurs after the specified delay time. If the time delay event
is cancelled before the time delay expires, the program interrupt does not occur.

Table 8- 96

SRT_DINT, CAN_DINT, and QRY_DINT instructions

LAD / FBD

Description
SRT_DINT starts a time delay interrupt that executes an OB when the delay time
specified by parameter DTIME has elapsed.

CAN_DINT cancels a time delay interrupt that has already started. The time delay
interrupt OB is not executed in this case.

QRY_DINT queries the status of the time delay interrupt specified by the OB_NR
parameter.

Table 8- 97

Data types for the parameters

Parameter and type

Data type

Description

OB_NR

OB_DELAY

Organization block (OB) to be started after a time-delay: Select from
the available time-delay interrupt OBs that were created using the "Add
new block" project tree feature. Double-click on the parameter field,
then click on the helper icon to see the available OBs.

DTIME 1

Time

Time delay value (1 to 60000 ms)

SIGN 1

Word

Not used by the S7-1200: Any value is accepted. A value must be
assigned to prevent errors.

RET_VAL

OUT

Int

Execution condition code

STATUS

OUT

Word

QRY_DINT instruction: Status of the specified time-delay interrupt OB,
see the table below

Only for SRT_DINT

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8.4 Interrupts

Operation
The SRT_DINT instruction specifies a time delay, starts the internal time delay timer, and
associates a time delay interrupt OB subprogram with the time delay timeout event. When
the specified time delay has elapsed, a program interrupt is generated that triggers the
execution of the associated time delay interrupt OB. You can cancel an in-process time
delay interrupt before the specified time delay occurs by executing the CAN_DINT
instruction. The total number of active time delay and cyclic interrupt events must not exceed
four.

Adding time delay interrupt OB subprograms to your project
Only time delay interrupt OBs can be assigned to the SRT_DINT and CAN_DINT
instructions. No time delay interrupt OB exists in a new project. You must add time delay
interrupt OBs to your project. To create a time-delay interrupt OB, follow these steps:
1. Double-click the "Add new block" item in the "Program blocks" branch of the project tree,
select "Organization block (OB)", and choose "Time delay interrupt".
2. You have the option to rename the OB, select the programming language, or select the
block number. Switch to manual numbering if you want to assign a different block number
than the number that was assigned automatically.
3. Edit the time delay interrupt OB subprogram and create programmed reaction that you
want to execute when the time delay timeout event occurs. You can call other FC and FB
code blocks from the time delay interrupt OB, with a maximum nesting depth of four.
4. The newly assigned time delay interrupt OB names will be available when you edit the
OB_NR parameter of the SRT_DINT and CAN_DINT instructions.

QRY_DINT parameter STATUS
Table 8- 98

If there is an error (REL_VAL <> 0), then STATUS = 0.

Bit

Value

Description

In RUN

In startup

The interrupt is enabled.

The interrupt is disabled.

1
2
4

The interrupt is not active or has elapsed.

The interrupt is active.

An OB with an OB number given in OB_NR does not exist.

1
Other bits

An OB with an OB number given in OB_NR exists.
Always 0

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8.4 Interrupts

Condition codes
Table 8- 99

8.4.4

Condition codes for SRT_DINT, CAN_DINT, and QRY_DINT

RET_VAL (W#16#...)

Description

0000

No error occurred

8090

Incorrect parameter OB_NR

8091

Incorrect parameter DTIME

80A0

Time delay interrupt has not started.

Asynchronous event interrupts
Use the DIS_AIRT and EN_AIRT instructions to disable and enable alarm interrupt
processing.

Table 8- 100 DIS_AIRT and EN_AIRT instructions
LAD / FBD

Description
DIS_AIRT delays the processing of new interrupt events. You can execute DIS_AIRT more than once in
an OB.

EN_AIRT enables the processing of interrupt events that you previously disabled with the DIS_AIRT
instruction. Each DIS_AIRT execution must be cancelled by an EN_AIRT execution.
The EN_AIRT executions must occur within the same OB, or any FC or FB called from the same OB,
before interrupts are enabled again for this OB.

Table 8- 101 Data types for the parameters
Parameter and type
RET_VAL

OUT

Data type

Description

Int

Number of delays = number of DIS_AIRT executions in the queue.

The DIS_AIRT executions are counted by the operating system. Each of these remains in
effect until it is cancelled again specifically by an EN_AIRT instruction, or until the current OB
has been completely processed. For example: if you disabled interrupts five times with five
DIS_AIRT executions, you must cancel these with five EN_AIRT executions before interrupts
become enabled again.
After the interrupt events are enabled again, the interrupts that occurred while DIS_AIRT was
in effect are processed, or the interrupts are processed as soon as the current OB has been
executed.
Parameter RET_VAL indicates the number of times that interrupt processing was disabled,
which is the number of queued DIS_AIRT executions. Interrupt processing is only enabled
again when parameter RET_VAL = 0.

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8.5 Diagnostics

8.5

Diagnostics

8.5.1

LED instruction

Table 8- 102 LED instruction
LAD / FBD

Description
Use the LED instruction to read the state of the LEDs on a CPU or interface. The specified LED state is
returned by the RET_VAL output.

Table 8- 103 Data types for the parameters
Parameter and type

Data type

Description

LADDR

HW_IO

Identification number of the CPU or interface1

LED

UInt

LED identifier number

RET_VAL
1

OUT

Int

RUN/STOP

Color 1 = green, color 2 = yellow

Error

Color 1 = red

Maintenance

Color 1 = yellow

Redundancy

Not applicable

Link

Color 1 = green

Tx/Rx

Color 1 = yellow

Status of the LED

For example, you can select the CPU (such as "PLC_1") or the PROFINET interface from the drop-down list of the
parameter.

Table 8- 104 Status of RET_VAL
RET_VAL (W#16#...)

Description

0 to 9 LED state

LED does not exist

Off

Color 1 On (solid)

Color 2 On (Solid)

Color 1 flashing at 2 Hz

Color 2 flashing 2 Hz

Color 1 & 2 flashing alternatively at 2 Hz

Color 1 on (Tx/Rx)

Color 2 on (Tx/Rx)

State of the LED is not available

8091

Device identified by LADDR does not exist

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8.5 Diagnostics

RET_VAL (W#16#...)

Description

8092

Device identified by LADDR does not support LEDs

8093

LED identifier not defined

80Bx

CPU identified by LADDR does not support the LED instruction

8.5.2

DeviceStates instruction

Table 8- 105 DeviceStates instruction
LAD / FBD

Description
Retrieves the I/O device operational states of an I/O subsystem. This information
corresponds with the STEP 7 diagnostics view.

Table 8- 106 Data types for the parameters

Parameter and type

Data type

Description

LADDR

HW_IOSYSTEM

Logical address: (Identifier for the I/O system)

MODE

UInt

Status type:


1: Configured stations



2: Defective stations



3: Deactivated stations



4: Existing stations

RET_VAL

OUT

Int

Execution condition code

STATE1

InOut

Variant

Buffer containing the error status of each device:


Summary bit: Bit 0 =1, if one of the state bits of the I/O devices
is 1



State bit: State of I/O device with station number n according to
the selected MODE. For example, MODE = 2 and bit 3 = 1
means station 3 is faulty.

For PROFIBUS-DP, the length of the status information is 128 bits. For PROFIBUS I/O, the length is 1024 bits.

After execution, the STATE parameter contains the error state of each I/O device as a bit list
(for the specified LADDR and MODE).
The data type used for the STATE parameter can be any bit type (Bool, Byte, Word, or
DWord) or an array of a bit type.

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8.5 Diagnostics
Table 8- 107 Condition codes
RET_VAL (W#16#...)

Description

No error

8091

LADDR does not exist.

8092

LADDR does not address an I/O system.

80Bx

DeviceStates instruction not supported by the CPU for this LADDR.

8452

The complete state data is too large for STATE. The STATE parameter contains a partial
result.

8.5.3

ModuleStates instruction

Table 8- 108 ModuleStates instruction
LAD / FBD

Description
Retrieves the I/O module operational states of I/O devices. This information corresponds
with the STEP 7 diagnostics view.

Table 8- 109 Data types for the parameters

Parameter and type

Data type

Description

LADDR

HW_IOSYSTEM

Logical address (Identifier for the I/O device)

MODE

UInt

Status type:


1: Configured modules



2: Defective modules



3: Deactivated modules



4: Existing modules

RET_VAL

OUT

Int

Status (condition code)

STATE1

InOut

Variant

Buffer containing the error status of each device


Summary bit: Bit 0 =1, if one of the state bits of the I/O devices
is 1



State bit: State of I/O device with station number n according to
the selected MODE. For example, MODE = 2 and bit 3 = 1
means station 3 is faulty.

The length required is dependent on the I/O device, with a maximum of 128 bits.

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8.5 Diagnostics
Table 8- 110 Condition codes
RET_VAL ( W#16#...)

Description

No error

8091

Device identified by LADDR does not exist.

8092

Device identified by LADDR does not address an I/O device.

80Bx

ModuleStates instruction not supported by this CPU for this LADDR.

8452

The complete state data is too large for STATE. The STATE parameter contains a partial
result.

8.5.4

GET_DIAG instruction

Table 8- 111 GET_DIAG instruction
LAD / FBD

Description
Reads the diagnostic information from a specified hardware device.

Table 8- 112 Data types for the parameters
Parameter and type

Data type

Description

MODE

UInt

Mode

LADDR

HW_ANY (Word)

Identification number of the hardware device

DIAG

InOut

Variant

Diagnostic information according to diagnostic mode

DETAIL

InOut

Variant

Diagnostic detail according to diagnostic mode

RET_VAL

OUT

Int

Execution result / error message

CNT_DIAG

OUT

UInt

Count of the returned diagnostic details

Input LADDR selects the hardware device. The type of the delivered diagnostic information
is selected by the input MODE.
Table 8- 113 MODE parameter
MODE input

DIAG output

CNT_DIAG output

DETAIL output

Bit list of supported modes as DWord

Nothing

Diagnostic state as diagnostic information
source (DIS)

Nothing

Diagnostic navigation node (DNN)

Nothing

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8.5 Diagnostics
Table 8- 114 Structure of the diagnostic information source (DIS)
DIS: Struct;
OwnState:

UInt;

MaintenanceState:

DWord;

IOState:

Word;

ComponentStateDetail:

DWord;

OperatingState:

UInt;

End_Struct

Table 8- 115 Structure of the diagnostic navigation node (DNN)
DNN: Struct;
SubordinateState:

UInt;

SubordinateIOState:

Word;

DNNmode:

Word;

End_Struct

Table 8- 116 Condition codes
RET_VAL (W#16#...)

Description

No error

All of the n existing diagnostic details could not be provided.

8080

Mode not supported.

8081

Data type at parameter DIAG not supported with given mode.

8082

Data type at parameter DETAIL not supported with given mode.

8090

Device identified by LADDR does not exist.

8091

Channel does not exist.

80C1

Lack of resources for parallel executions.

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8.6 Pulse

8.6

Pulse

8.6.1

CTRL_PWM instruction

Table 8- 117 CTRL_PWM (Pulse Width Modulation) instruction
LAD / FBD

Description
Provides a fixed cycle time output with a variable duty cycle. The PWM output runs
continuously after being started at the specified frequency (cycle time). The pulse width is
varied as required to affect the desired control.

STEP 7 automatically creates the DB when you insert the instruction.

Table 8- 118 Data types for the parameters
Parameter and type

Data type

Description

PWM

HW_PWM
(Word)

PWM identifier: Names of enabled pulse generators will become tags in
the "constant" tag table, and will be available for use as the PWM
parameter. (Default value: 0)

ENABLE

Bool

1=start pulse generator

BUSY

OUT

Bool

Function busy (Default value: 0)

STATUS

OUT

Word

Execution condition code (Default value: 0)

0 = stop pulse generator

The CTRL_PWM instruction stores the parameter information in the DB. The data block
parameters are not separately changed by the user, but are controlled by the CTRL_PWM
instruction.
Specify the enabled pulse generator to use, by using its tag name for the PWM parameter.
When the EN input is TRUE, the PWM_CTRL instruction starts or stops the identified PWM
based on the value at the ENABLE input. Pulse width is specified by the value in the
associated Q word output address.
Because the CPU processes the request when the CTRL_PWM instruction is executed,
parameter BUSY will always report FALSE. If an error is detected, then ENO is set to
FALSE, and parameter STATUS contains a condition code.
The pulse width will be set to the initial value configured in device configuration when the
CPU first enters RUN mode. You write values to the Q-word location specified in device
configuration ("Output addresses" / "Start address:") as needed to change the pulse width.
You use an instruction such as a move, convert, math, or PID box to write the desired pulse
width to the appropriate Q word. You must use the valid range for the Q-word value (percent,
thousandths, ten-thousandths, or S7 analog format).

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8.6 Pulse

Note
Digital I/O points assigned to PWM and PTO cannot be forced
The digital I/O points used by the pulse-width modulation (PWM) and pulse-train output
(PTO) devices are assigned during device configuration. When digital I/O point addresses
are assigned to these devices, the values of the assigned I/O point addresses cannot be
modified by the Watch table force function.

Table 8- 119 Value of the STATUS parameter
STATUS

Description

No error

80A1

PWM identifier does not address a valid PWM.

Table 8- 120 Common condition codes

Condition code1

Description

8022

Area too small for input

8023

Area too small for output

8024

Illegal input area

8025

Illegal output area

8028

Illegal input bit assignment

8029

Illegal output bit assignment

8030

Output area is a read-only DB.

803A

DB does not exist.

If one of these errors occurs when a code block is executed, the CPU goes to STOP mode unless you use the GetError
or GetErrorID instructions within that code block to create a programmed reaction to the error.

8.6.2

Operation of the pulse outputs
཰
ཱ

①
②

Cycle time

ཱ

Pulse width can be expressed as hundredths of the
cycle time (0 to 100), as thousandths (0 to 1000), as
ten thousandths (0 to 10000), or as S7 analog format.
The pulse width can vary from 0 (no pulse, always off)
to full scale (no pulse, always on).

Pulse width

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8.6 Pulse
Since the PWM output can be varied from 0 to full scale, it provides a digital output that in
many ways is the same as an analog output. For example, the PWM output can be used to
control the speed of a motor from stop to full speed, or it can be used to control position of a
valve from closed to fully opened.
Two pulse generators are available for controlling high-speed pulse output functions: PWM
and Pulse train output (PTO). PTO is used by the motion control instructions. You can assign
each pulse generator to either PWM or PTO, but not both at the same time.
The two pulse generators are mapped to specific digital outputs as shown in the following
table. You can use onboard CPU outputs, or you can use the optional signal board outputs.
The output point numbers are shown in the following table (assuming the default output
configuration). If you have changed the output point numbering, then the output point
numbers will be those you assigned. Regardless, PTO1/PWM1 uses the first two digital
outputs, and PTO2/PWM2 uses the next two digital outputs, either on the CPU or on the
attached signal board. Note that PWM requires only one output, while PTO can optionally
use two outputs per channel. If an output is not required for a pulse function, it is available
for other uses.
NOTICE
Pulse-train outputs cannot be used by other instructions in the user program
When you configure the outputs of the CPU or signal board as pulse generators (for use
with the PWM or basic motion control instructions), the corresponding outputs addresses
(Q0.0, Q0.1, Q4.0, and Q4.1) are removed from the Q memory and cannot be used for
other purposes in your user program. If your user program writes a value to an output used
as a pulse generator, the CPU does not write that value to the physical output.

Table 8- 121 Default output assignments for the pulse generators
Description
PTO 1
PWM 1
PTO 2
PWM 2

Pulse

Direction

Onboard CPU

Q0.0

Q0.1

Signal board

Q4.0

Q4.1

Onboard CPU

Q0.0

Signal board

Q4.0

Onboard CPU

Q0.2

Q0.3

Signal board

Q4.2

Q4.3

Onboard CPU

Q0.2

Signal board

Q4.2

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8.6 Pulse

8.6.3

Configuring a pulse channel for PWM
To prepare for PWM operation, first configure a pulse channel in the device configuration by
selecting the CPU, then Pulse Generator (PTO/PWM), and choose either PWM1 or PWM2.
Enable the pulse generator (check box). If a pulse generator is enabled, a unique default
name is assigned to this particular pulse generator. You can change this name by editing it
in the "Name:" edit box, but it must be a unique name. Names of enabled pulse generators
will become tags in the "constant" tag table, and will be available for use as the PWM
parameter of the CTRL_PWM instruction.
NOTICE
The maximum pulse frequency of the pulse output generators for the digital output is
100 KHz (for the CPU), 20 KHz (for a SB), or 200 KHz (for a high-speed SB). However,
STEP 7 does not alert you when you configure an axis that with a maximum speed or
frequency that exceeds this hardware limitation. This could cause problems with your
application, so always ensure that you do not exceed the maximum pulse frequency of the
hardware.
You have the option to rename the pulse generator, add a comment, and assign parameters
as follows:
● Pulse generator used as follows: PWM or PTO (choose PWM)
● Output source: onboard CPU or SB
● Time base: milliseconds or microseconds
● Pulse width format:
– Hundredths (0 to 100)
– Thousandths (0 to 1000)
– Ten-thousandths (0 to 10000)
– S7 analog format (0 to 27648)
● Cycle time: Enter your cycle time value. This value can only be changed in Device
configuration.
● Initial pulse width: Enter your initial pulse width value. The pulse width value can be
changed during runtime.
Enter the start address to configure the output addresses. Enter the Q word address where
you want to locate the pulse width value.
NOTICE
Pulse-train outputs cannot be used by other instructions in the user program
When you configure the outputs of the CPU or signal board as pulse generators (for use
with the PWM or basic motion control instructions), the corresponding outputs addresses
(Q0.0, Q0.1, Q4.0, and Q4.1) are removed from the Q memory and cannot be used for
other purposes in your user program. If your user program writes a value to an output used
as a pulse generator, the CPU does not write that value to the physical output.

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8.7 Data block control
The default location is QW1000 for PWM1, and QW1002 for PWM2. The value at this
location controls the width of the pulse and is initialized to the "Initial pulse width:" value
specified above each time the CPU transitions from STOP to RUN mode. You change this
Q-word value during run time to cause a change in the pulse width.

8.7

Data block control

8.7.1

READ_DBL, WRIT_DBL (Read from or write to a DB in load memory)

Table 8- 122 READ_DBL and WRIT_DBL instructions
LAD / FBD

Description
Copies DB start values or part of the values, from load memory to a target DB in
the work memory.
The content of load memory is not changed during the copy process.

Copies DB start values or part of the values from work memory to a target DB in
load memory.
The content of work memory is not changed during the copy process.

Table 8- 123 Data types for the parameters
Parameter and type

Data type

Description

REQ

BOOL

A high signal starts the operation, if BUSY = 0.

SRCBLK

VARIANT

READ_DBL: Pointer to the source data block in load memory
WRIT_DBL: Pointer to the source data block in work memory

RET_VAL

OUT

INT

Execution condition code

BUSY

OUT

BOOL

BUSY = 1 signals that the reading/writing process is not complete.

DSTBLK

OUT

VARIANT

READ_DBL: Pointer to the destination data block work memory
WRIT_DBL: Pointer to the destination data block in load memory

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8.7 Data block control
READ_DBL can be used to copy a set of start values to a DB in work memory that is
referenced by your program. You can use WRIT_DBL to update the start values stored in
internal load memory or memory card.
Note
Avoid excessive WRIT_DBL flash memory write operations
The WRIT_DBL instruction performs write operations in flash memory (internal load memory
or memory card). WRIT_DBL should be used for infrequent updates like a production
process changes.
The data blocks used by READ_DBL and WRIT_DBL must have been previously created by
STEP 7 before you can use these instructions. If the source data block is created as a
"Standard" type then the destination data block must also be the "Standard" type. If the
source data block is created as an "Optimized" type then the destination data block must
also be the "Optimized" type.
READ_DBL and WRIT_DBL execute asynchronously to the cyclic program scan. The
processing extends over multiple READ_DBL and WRIT_DBL calls. You start the DB
transfer job by calling with REQ = 1 and then monitor the BUSY and RET_VAL outputs to
determine when the data transfer is complete and correct.
To ensure data consistency, do not modify the destination area during the processing of
READ_DBL or the source area during the processing of WRIT_DBL (that is, as long as the
BUSY parameter is TRUE).
SRCBLK and DSTBLK parameter restrictions:
● A data block must have been previously created before it can be referenced.
● The length of a VARIANT pointer of type BOOL must be divisible by 8.
● The length of a VARIANT pointer of type STRING must be the same in the source and
destination pointers.
Table 8- 124 Condition codes
RET_VAL

Description

(W#16#...)
0000

No error

0081

Warning: that the source area is smaller than the destination area. The source data is copied
completely with the extra bytes in the destination area unchanged.

7000

Call with REQ = 0: BUSY = 0

7001

First call with REQ = 1 (working): BUSY = 1

7002

Nth call (working): BUSY = 1

8051

Data block type error

8081

The source area is larger than the destination area. The destination area is completely filled and the
remaining bytes of the source are ignored.

8251

Source data block type error

82B1

Missing source data block

82C0

The source DB is being edited by another statement or a communication function.

8551

Destination data block type error

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8.8 Common error codes for the "Extended" instructions

RET_VAL

Description

(W#16#...)
85B1

Missing destination data block

85C0

The destination DB is being edited by another statement or a communication function.

80C3

More than 50 READ_DBL or 50 WRIT_DBL statements are currently queued for execution.

8.8

Common error codes for the "Extended" instructions

Table 8- 125 Common condition codes for the extended instructions

Condition code (W#16#....)1

Description

8022

Area too small for input

8023

Area too small for output

8024

Illegal input area

8025

Illegal output area

8028

Illegal input bit assignment

8029

Illegal output bit assignment

8030

Output area is a read-only DB.

803A

DB does not exist.

If one of these errors occurs when a code block is executed the the CPU goes to STOP mode, unless you use the
GetError or GetErrorID instructions within that code block and create a programmed reaction to the error.

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8.8 Common error codes for the "Extended" instructions

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Data logging

Your control program can use the Data log instructions to store run-time data values in
persistent log files. The data log files are stored in flash memory (CPU or memory card). Log
file data is stored in standard CSV (Comma Separated Value) format. The data records are
organized as a circular log file of a pre-determined size.
The Data log instructions are used in your program to create, open, write a record, and close
the log files. You decide which program values will be logged by creating a data buffer that
defines a single log record. Your data buffer is used as temporary storage for a new log
record. New current values must be programmatically moved into the buffer during run-time.
When all of the current data values are updated, you can execute the DataLogWrite
instruction to transfer data from the buffer to a data log record.
Use the built-in PLC Web server to manage your data log files. Download recent records, all
records, clear records, or delete log files with the "Data Logs" standard web page. After a
data log file is transferred to your PC, then you can analyze the data with standard
spreadsheet tools like Microsoft Excel.

9.1

Data log record structure
The DATA and HEADER parameters of the DataLogCreate instruction assign the data type
and the column header description of all data elements of a log record.

DATA parameter for the DataLogCreate instruction
The DATA parameter points to memory used as a temporary buffer for a new log record and
must be assigned to an M or DB location.
You can assign an entire DB (derived from a PLC data type that you assign when the DB is
created) or part of a DB (the specified DB element can be any data type, data type structure,
PLC data type, or data array).
Structure data types are limited to a single nesting level. The total number of data elements
declared should correspond to the number of columns specified in the header parameter.
The maximum number of data elements you can assign is 253 (with a timestamp) or 255
(without a timestamp). This restriction keeps your record inside the 256 column limit of a
Microsoft Excel sheet.
The DATA parameter can assign either retentive or non-retentive data elements in a
"Standard" (compatible with S7-300/400) or "Optimized" DB type.
In order to write a Data log record you must first load the temporary DATA record with new
process values and then execute the DataLogWrite instruction that saves new record values
in the Datalog file.

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9.2 Program instructions that control Data logs

HEADER parameter for the DataLogCreate instruction
The HEADER parameter points to column header names for the top row of the data matrix
encoded in the CSV file. HEADER data must be located in DB or M memory and the
characters must follow standard CSV format rules with commas separating each column
name. The data type may be a string, byte array, or character array. Character/byte arrays
allow increased size, where strings are limited to a maximum of 255 bytes. The HEADER
parameter is optional. If the HEADER is not parameterized, then no header row is created in
the Data log file.

9.2

Program instructions that control Data logs

9.2.1

DataLogCreate

Table 9- 1

DataLogCreate instruction

LAD/FBD

Description
Creates and initializes a data log file. The file is created in the PLC \DataLogs directory,
named by the NAME parameter, and implicitly opened for write operations. You can use
the Data log instructions to programmatically store run-time process data in flash
memory of the CPU.
STEP 7 automatically creates the associated instance DB when you insert the
instruction.

Table 9- 2

Data types for the parameters

Parameter and type

Data type

Description

REQ

Bool

A low to high (positive edge) signal starts the operation. (Default value:
False)

RECORDS

UDint

The maximum number of data records the circular data log can contain
before overwriting the oldest entry:
The header record is not included. Sufficient available PLC load memory
must exist in order to successfully create the data log. (Default value: 1)

FORMAT

UInt

Data log format:


0: Internal format (not supported)



1: Comma separated values "csv-eng" (Default value)

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Parameter and type

Data type

Description

TIMESTAMP

UInt

Data time stamp format: (Column headers for date and time fields are not
required)

NAME

Variant



0: No time stamp



1: Date and time stamp (Default value)

Data log name: You provide the name. This variant only supports a String
data type and can only be located in local, DB, or M memory. (Default value:
' ')
The string reference is also used as the name of the data log file. The name
characters must follow the Windows file system naming restrictions.
Characters \ / : * ? " < > | and the space character are not allowed.

In/Out

DWord

Data log numeric identifier: You store this generated value for use with other
Data log instructions. The ID parameter is only used as an output with the
DataLogCreate instruction. (Default value: 0)
Symbolic name access for this parameter is not allowed.

HEADER

In/Out

Variant

Pointer to data log column header names for the top row of the data matrix
encoded in the CSV file. (Default value: null).
HEADER data must be located in DB or M memory.
The characters must follow standard CSV format rules with commas
separating each column name. The data type may be a string, byte array, or
character array. Character/byte arrays allow increased size, where strings
are limited to a maximum of 255 bytes.
The HEADER parameter is optional. If the HEADER is not parameterized,
then no header row is created in the Data log file.

DATA

In/Out

Variant

Pointer to the record data structure, user defined type (UDT), or array.
Record data must be located in DB or M memory.
The DATA parameter specifies the individual data elements (columns) of a
data log record and their data type. Structure data types are limited to a
single nesting level. The number of data elements declared should
correspond to the number of columns specified in the header parameter.
The maximum number of data elements you can assign is 253 (with a
timestamp) or 255 (without a timestamp). This restriction keeps your record
inside the 256 column limit of a Microsoft Excel sheet.

DONE

OUT

Bool

The DONE bit is TRUE for one scan, after the last request was completed
with no error. (Default value: False)

BUSY

OUT

Bool



0 - No operation in progress



1 - Operation on progress

ERROR

OUT

Bool

The ERROR bit is TRUE for one scan, after the last request was terminated
with an error. The error code value at the STATUS parameter is valid only
during the single scan where ERROR = TRUE.

STATUS

OUT

Word

Execution condition code (Default value: 0)

A data log file is created with a pre-determined fixed sized based on the RECORDS and
DATA parameters. The data records are organized as a circular log file. New records are
appended to the data log file, until the maximum number of records that is specified by the
RECORDS parameter is stored. The next record written will overwrite the oldest record.
Another record write operation will overwrite the next oldest data record and so on.

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9.2 Program instructions that control Data logs

Note
If you want to prevent overwriting any data records, then you can use the DataLogNewFile
instruction to create a new data log based on the current data log, after the current data log
has stored the maximum number of records. New data records are stored in the new data
log file. The old data log file and record data remains in flash memory of the CPU.
Memory resource usage:
● The data logs consume only load memory.
● There is no set limit for the total number of data logs. The size of all data logs combined
is limited by the available resources of load memory. Only eight data logs may be open at
one time.
● The maximum possible number for the RECORDS parameter is the limit for an UDint
number (4,294,967,295). The actual limit for the RECORD parameter depends on the
size of a single record, the size of other data logs, and the available resources of load
memory. In addition, Microsoft Excel has limits on the number of rows allowed in an Excel
sheet.
Note
A DataLogCreate operation extends over many program scan cycles. The actual time
required for the log file creation depends on the record structure and number of records.
Your program logic must monitor and catch the DataLogCreate DONE bit's transition to
the TRUE state, before the new data log can be used for other data log operations.

Table 9- 3

Values of ERROR and STATUS

ERROR

STATUS (W#16#....)

Description

0000

No error

7000

Call with no REQ edge: BUSY = 0, DONE = 0

7001

First call with REQ edge (working): BUSY = 1, DONE = 0

7002

Nth call (working): BUSY = 1, DONE = 0

8070

All internal instance memory is in use.

807F

Internal error

8090

Invalid file name

8091

Name parameter is not a String reference.

8093

Data log already exists.

8097

Requested file length exceeds file system maximum.

80B3

Insufficient load memory available.

80B4

MC (Memory Cartridge) is write protected.

80C1

Too many open files: No more than eight opened data log files are allowed.

8253

Invalid record count

8353

Invalid format selection

8453

Invalid timestamp selection

8B24

Invalid HEADER area assignment: For example, pointing to local memory

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ERROR

STATUS (W#16#....)

Description

8B51

Invalid HEADER parameter data type

8B52

Too many HEADER parameter data elements

8C24

Invalid DATA area assignment: For example, pointing to local memory

8C51

Invalid DATA parameter data type

8C52

Too many DATA parameter data elements

9.2.2
Table 9- 4

DataLogOpen
DataLogOpen instruction

LAD / FBD

Description
Opens a pre-existing data log file. A data log must be opened before you can write new records to the
log. Data logs can be opened and closed individually. A maximum of eight data logs can be open at
the same time.
STEP 7 automatically creates the associated instance DB when you insert the instruction.

Table 9- 5

Data types for the parameters

Parameter and type

Data type

Description

REQ

Bool

A low to high (positive edge) signal starts the operation. (Default value:
False)

MODE

UInt

Operation mode:


0 - Append to existing data (Default value)



1 - Clear all existing records

NAME

Variant

Name of an existing data log: This variant only supports a String data type
and can only be located in local, DB, or M memory. (Default value: ' ')

In/Out

DWord

Numeric identifier of a data log. (Default value: 0)
Note: Symbolic name access for this parameter is not allowed.

DONE

OUT

Bool

The DONE bit is TRUE for one scan, after the last request was completed
with no error. (Default value: False)

BUSY

OUT

Bool



0 - No operation in progress



1 - Operation on progress

ERROR

OUT

Bool

The ERROR bit is TRUE for one scan, after the last request was
terminated with an error. The error code value at the STATUS parameter
is valid only during the single scan where ERROR = TRUE.

STATUS

OUT

Word

Execution condition code (Default value: 0)

You can provide either the NAME or an ID (ID parameter as an input) of a pre-existing data
log. If you provide both parameters and a valid ID does correspond to the NAME data log,
then the ID is used, and the NAME ignored.

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The NAME must be the name of a data log created by the DataLogCreate instruction. If only
the NAME is provided and the NAME specifies a valid data log, then the corresponding ID
will be returned (ID parameter as an output).
Note
General usage of data log files
 Data log files are automatically opened after the DataLogCreate and DataLogNewFile
operations.
 Data log files are automatically closed after a PLC run to stop transition or a PLC power
cycle.
 A Data log file must be open before a new DataLogWrite operation is possible.
 A maximum of eight data log files may be open at one time. More than eight data log files
may exist, but some of them must be closed so no more than eight are open.

Table 9- 6

Values of ERROR and STATUS

ERROR

STATUS (W#16#)

Description

0000

No error

0002

Warning: Data log file already open by this application program

7000

Call with no REQ edge: BUSY = 0, DONE = 0

7001

First call with REQ edge (working): BUSY = 1, DONE = 0

7002

Nth call (working): BUSY = 1, DONE = 0

8070

All internal instance memory is in use.

8090

Data log definition is inconsistent with existing data log file.

8091

Name parameter is not a String reference.

8092

Data log does not exist.

80C0

Data log file is locked.

80C1

Too many open files: No more than eight opened data log files are allowed.

9.2.3
Table 9- 7
LAD / FBD

DataLogClose
DataLogClose instruction
Description
Closes an open data log file. DataLogWrite operations to a closed data log result in an error. No write
operations are allowed to this data log until another DataLogOpen operation is performed.
A transition to STOP mode will close all open data log files.
STEP 7 automatically creates the associated instance DB when you insert the instruction.

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Table 9- 8

Data types for the parameters

Parameter and type

Data type

Description

REQ

Bool

A low to high (positive edge) signal starts the operation. (Default value: False)

In/Out

DWord

Numeric identifier of a data log. Only used as an input for the DataLogClose
instruction. (Default value: 0)

DONE

OUT

Bool

The DONE bit is TRUE for one scan after the last request was completed with
no error.

BUSY

OUT

Bool



0 - No operation in progress



1- Operation on progress

Note: Symbolic name access for this parameter is not allowed.

ERROR

OUT

Bool

The ERROR bit is TRUE for one scan, after the last request was terminated
with an error. The error code value at the STATUS parameter is valid only
during the single scan where ERROR = TRUE.

STATUS

OUT

Word

Execution condition code (Default value: 0)

Table 9- 9

Values of ERROR and STATUS

ERROR

STATUS (W#16#)

Description

0000

No error

0001

Data log not open

7000

Call with no REQ edge: BUSY = 0, DONE = 0

7001

First call with REQ edge (working): BUSY = 1, DONE = 0

7002

Nth call (working): BUSY = 1, DONE = 0

8092

Data log does not exist.

9.2.4
Table 9- 10
LAD / FBD

DataLogWrite
DataLogWrite instruction
Description
Writes a data record into the specified data log. The pre-existing target data log must be open before
a DataLogWrite operation is allowed.
STEP 7 automatically creates the associated instance DB when you insert the instruction.

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9.2 Program instructions that control Data logs
Table 9- 11

Data types for the parameters

Parameter and type

Data type

Description

REQ

Bool

A low to high (positive edge) signal starts the operation. (Default value: False)

In/Out

DWord

Numeric data log identifier. Only used as an input for the DataLogWrite
instruction. (Default value: 0)

DONE

OUT

Bool

The DONE bit is TRUE for one scan, after the last request was completed with
no error.

BUSY

OUT

Bool



0 - No operation in progress



1 - Operation on progress

Note: Symbolic name access for this parameter is not allowed.

ERROR

OUT

Bool

The ERROR bit is TRUE for one scan, after the last request was terminated
with an error. The error code value at the STATUS parameter is valid only
during the single scan where ERROR = TRUE.

STATUS

OUT

Word

Execution condition code (Default value: 0)

The memory address and data structure of the record buffer is configured by the DATA
parameter of a DataLogCreate instruction. You must programmatically load the record buffer
with current run-time process values and then execute the DataLogWrite instruction to move
new record data from the buffer to the data log.
The ID parameter identifies a data log and data record configuration. The ID number is
generated when a data log is created.
If there are empty records in the circular data log file, then the next available empty record
will be written. If all records are full, then the oldest record will be overwritten.
CAUTION
Potential for data log data loss during a CPU power failure
If there is a power failure during an incomplete DataLogWrite operation, then the data
record being transferred to the data log could be lost.

Table 9- 12

Values of ERROR and STATUS

ERROR

STATUS (W#16#)

Description

0000

No error

0001

Indicates that the data log is full: Each data log is created with a specified
maximum number of records. The last record of the maximum number has been
written. The next write operation will overwrite the oldest record.

7000

Call with no REQ edge: BUSY = 0, DONE = 0

7001

First call with REQ edge (working): BUSY = 1, DONE = 0

7002

Nth call (working): BUSY = 1, DONE = 0

8070

All internal instance memory is in use.

8092

Data log does not exist.

80B0

Data log file is not open (for explicit open mode only).

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9.2.5
Table 9- 13

DataLogNewFile
DataLogNewFile instruction

LAD / FBD

Description
Allows your program to create a new data log file based upon an existing data log file.
STEP 7 automatically creates the associated instance DB when you insert the instruction.

Table 9- 14

Data types for the parameters

Parameter and type

Data type

Description

REQ

Bool

A low to high (positive edge) signal starts the operation. (Default value:
False)

RECORDS

UDInt

The maximum number of data records the circular data log can contain
before overwriting the oldest entry. (Default value: 1)
The header record is not included. Sufficient available CPU load memory
must exist in order to successfully create the data log.

NAME

Variant

In/Out

DWord

Numeric data log identifier(Default value: 0):


At execution, the ID input identifies a valid data log. The new data log
configuration is copied from this data log.

After execution, the ID parameter becomes an output that returns the ID
of the newly created data log file.
Note: Symbolic name access for this parameter is not allowed.


DONE

OUT

Bool

The DONE bit is TRUE for one scan, after the last request was completed
with no error.

BUSY

OUT

Bool



0 - No operation in progress



1 - Operation on progress

ERROR

OUT

Bool

The ERROR bit is TRUE for one scan, after the last request was terminated
with an error. The error code value at the STATUS parameter is valid only
during the single scan where ERROR = TRUE.

STATUS

OUT

Word

Execution condition code (Default value: 0)

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9.2 Program instructions that control Data logs
You can execute the DataLogNewFile instruction when a data log becomes full or is deemed
completed and you do not want to lose any data that is stored in the data log. A new empty
data log file can be created based on the structure of the full Data log file. The header record
will be duplicated from the original data log with the original data log properties (DATA record
buffer, data format, and timestamp settings). The original Data log file is implicitly closed and
the new Data log file is implicitly opened.
DataLogWrite parameter trigger: Your program must monitor the ERROR and STATUS
parameters of each DataLogWrite operation. When the final record is written and a data log
is full, the DataLogWrite ERROR bit = 1 and the DataLogWrite STATUS word = 1. These
ERROR and STATUS values are valid for one scan only, so your monitoring logic must use
ERROR = 1 as a time gate to capture the STATUS value and then test for STATUS = 1 (the
data log is full).
DataLogNewFile operation: When your program logic gets the data log is full signal, this
state is used to activate a DataLogNewFile operation. You must execute DataLogNewFile
with the ID of an existing (usually full) and open data log, but a new unique NAME
parameter. After the DataLogNewFile operation is done, a new data log ID value is returned
(as an output parameter) that corresponds to the new data log name. The new data log file is
implicitly opened and is ready to store new records. New DataLogWrite operations that are
directed to the new data log file, must use the ID value returned by the DataLogNewFile
operation.
Note
A DataLogNewFile operation extends over many program scan cycles. The actual time
required for the log file creation depends on the record structure and number of records.
Your program logic must monitor and catch the DataLogNewFile DONE bit's transition to the
TRUE state, before the new data log can be used for other data log operations.

Table 9- 15

Values of ERROR and STATUS

ERROR

STATUS (W#16#)

Description

0000

No error

7000

Call with no REQ edge: BUSY = 0, DONE = 0

7001

First call with REQ edge (working): BUSY = 1, DONE = 0

7002

Nth call (working): BUSY = 1, DONE = 0

8070

All internal instance memory is in use.

8090

Invalid file name

8091

Name parameter is not a String reference.

8092

Data log does not exist.

8093

Data log already exists.

8097

Requested file length exceeds file system maximum.

80B3

Insufficient load memory available.

80B4

MC is write protected.

80C1

Too many open files.

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9.3 Working with data logs

9.3

Working with data logs
The data log files are stored as comma separated value format (*.csv) in persistent flash
memory. You can view the data logs by using the PLC Web server feature or by removing
the PLC memory card and inserting it in a standard PC card reader.

Viewing data logs with the PLC Web server feature
If the PLC PROFINET port and a PC are connected to a network, then you can use a PC
web browser like Microsoft Internet Explorer or Mozilla Firefox to access the built-in PLC
Web server. The PLC may be in run mode or stop mode when you operate the PLC Web
server. If the PLC is in run mode, then your control program continues to execute while the
PLC Web server is transferring log data through the network.
Web server access:
1. Enable the Web server in the Device Configuration for the target CPU (Page 492).
2. Connect your PC to the PLC through the PROFINET network (Page 492).
3. Log in to the built-in Web server (Page 494).
4. Download the recent records, all records, clear records, or delete log files with the "Data
Log" standard web page (Page 503).
5. After a copy of a data log file is downloaded to your PC, you can open the .csv file with a
spreadsheet application like Microsoft Excel.

Viewing data logs on a PLC memory card
If the S7-1200 CPU has a "Program" type S7-1200 memory card inserted, then you can
remove the memory card and insert the card into a standard SD (Secure Digital) or MMC
(MultiMediaCard) card slot on a PC or PG. The PLC is in stop mode when the memory card
is removed and your control program is not executed.
Use the Windows file explorer and navigate to the \DataLog directory on the memory card.
All your \*.csv data log files are located in this directory.
Make a copy of the data log files and put the copies on a local drive of your PC. Then, you
can use Microsoft Excel to open a local copy of a *.csv file and not the original file that is
stored on the memory card.
CAUTION
You can copy, but do not modify or delete data log files on a S7-1200 memory card using a
PC card reader
The standard Web server data log page is the recommended tool for viewing, downloading
(copying), clearing (delete the data), and deleting data log files. The Web server manages
the memory card files for you and helps prevent accidental modification or deletion of data.
Direct browsing of the memory card file system by the Windows Explorer has the risk that
you can accidentally delete/modify data log or other system files which may corrupt a file or
make the memory card unusable.

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9.4 Limits to the size of data log files

9.4

Limits to the size of data log files
Data log files share PLC load memory space along with the program, program data,
configuration data, web pages, and PLC system data. A large program using internal load
memory will consume a large amount of the available memory and there may be insufficient
space for data logs. In this case, you can use a "Program card" card to expand the amount
of load memory.
Refer to the memory card chapter for details about how to create a "Program" card
(Page 100).

Table 9- 16

Load memory sizes

Data area

CPU 1211
Size

CPU 1212
Size

CPU 1214
Size

Data storage

Internal load memory:
flash memory

1 MB

2 MB

User program and program
data, data logs, web
pages, plus
PLC system data

External load memory:
Optional "Program
card" flash memory
cartridges.

2 MB to 24 MB depending on the SD card size

Determine the size of load memory free space
1. Establish an online connection between STEP 7 and the target S7-1200 PLC.
2. Download the program to which you want to add data log operations.
3. Create any optional user-defined web pages that you need. (The standard web pages
that give you access to data logs are stored in PLC firmware and do not consume load
memory).
4. Use the Online and diagnostic tools to get the load memory size and percentage of free
load memory space (Page 550).
5. Multiply the load memory size by the percentage that is free to obtain the current load
memory free space.

Determine the practical maximum space available for data logs
The amount of load memory free space varies during normal operations as the operating
system uses and releases memory. You should limit the combined size of all data log files to
one half of the available free space.

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9.4 Limits to the size of data log files

Calculate the memory requirement for a single data log record
Log data is stored as character bytes in the CSV (comma separated values) file format. The
following table shows the number of bytes that are required to store each data type.
Table 9- 17

CSV file data sizes

Data type

Number of bytes (data bytes plus separator comma byte)

Bool

Byte

Word

DWord

Char

String

257 (Fixed size): Regardless of number of actual text characters
The string text characters + automatic padding with blank characters = 254 bytes
Opening and closing double quote + comma characters = 3 bytes
254 + 3 = 257 bytes

USInt

UInt

UDInt

SInt

Int

DInt

Real

LReal

Time

DTL

The DataLogCreate DATA parameter points to a structure that specifies the number of data
fields and the data type of each data field for one data log record. The table above gives the
bytes required in the CSV file for each data type. Multiply the number of occurrences of a
given data type by the number of bytes it requires. Do this for each data type in the record
and sum the number of bytes to get the total size of the data record. Add one byte for the
end of line character.
Size of a data log record = summation of bytes required for all data fields + 1 (the end of line
character).

Calculate the memory requirement for an entire data log file
The RECORDS parameter of the DataLogCreate instruction sets the maximum number of
records in a data log file. When the data log file is created the maximum memory size is
allocated.
Size of data log file = (number of bytes in one record) x (number of records).

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9.5 Data log example program

9.5

Data log example program
This Data log example program does not show all the program logic necessary to get sample
values from a dynamic process, but does show the key operations of the Data log
instructions. The structure and number of log files that you use depends on your process
control requirements.
Note
General usage of Data log files
 Data log files are automatically opened after the DataLogCreate and DataLogNew File
operations.
 Data log files are automatically closed after a PLC run to stop transition or a PLC power
cycle.
 A Data log file must be open before a DataLogWrite operation is possible.
 A maximum of eight data log files may be open at one time. More than eight data log files
may exist, but some of them must be closed so no more than eight are open.

Example Data log program
Example data log names, header text, and the MyData structure are created in a data block.
The three MyData variables temporarily store new sample values. The process sample
values at these DB locations are transferred to a data log file by executing the DataLogWrite
instruction.

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9.5 Data log example program
Network 1 REQ rising edge starts the data log creation process.

Network 2 Capture the DONE output from DataLogCreate because it is only valid for one
scan.

Network 3 A positive edge signal triggers when to store new process values in the MyData
structure.

Network 4 The EN input state is based upon when the DataLogCreate operation is complete.
A create operation extends over many scan cycles and must be complete before executing a
write operation. The positive edge signal on the REQ input is the event that triggers an
enabled write operation.

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9.5 Data log example program
Network 5 Close the data log once the last record has been written. After executing the
DataLogWrite operation that writes the last record, the log file full status is signaled when
DataLogWrite STATUS output = 1.

Network 6 A positive signal edge DataLogOpen REQ input simulates the user pushing a
button on an HMI that opens a data log file. If you open a Data log file that has all records
filled with process data, then the next DataLogWrite operation will overwrite the oldest
record. You may want to preserve the old Data log and instead create a new data log, as
shown in network 7.

Network 7 The ID parameter is an IN/OUT type. First, you supply the ID value of the existing
Data log whose structure you want to copy. After the DataLogNewFile operation is complete,
a new and unique ID value for the new Data log is written back to the ID reference location.
The required DONE bit = TRUE capture is not shown, refer to networks 1, 2, and 4 for an
example of DONE bit logic.

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9.5 Data log example program

Data log files created by the example program viewed with the S7-1200 CPU Webserver

Table 9- 18

Downloaded .csv file examples viewed with Microsoft Excel

Two records written in a five record
maximum file

Five records in a Data log file with a five
record maximum

After one additional record is written to the
file above which is full, the sixth write
operation overwrites the oldest record one
with record six. Another write operation
will overwrite record two with record
seven and so on.

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10.1
Table 10- 1

High-speed counter
CTRL_HSC instruction

LAD / FBD

Description
Each CTRL_HSC instruction uses a structure stored in a DB to maintain data. You assign
the DB when the CTRL_HSC instruction is placed in the editor.

STEP 7 automatically creates the DB when you insert the instruction.

Table 10- 2

Data types for the parameters

Parameter and type
HSC

Data type

Description

HW_HSC

HSC identifier

DIR1, 2

Bool

1 = Request new direction

CV1

Bool

1 = Request to set new counter value

RV1

Bool

1= Request to set new reference value

PERIOD1

Bool

1 = Request to set new period value
(only for frequency measurement mode)

NEW_DIR

Int

New direction: 1= forward, -1= backward

NEW_CV

DInt

New counter value

NEW_RV

DInt

New reference value

NEW_PERIOD

Int

New period value in seconds: 0.01, 0.1, or 1
(only for frequency measurement mode)

BUSY3

OUT

Bool

Function is busy

STATUS

OUT

Word

Execution condition code

If an update of a parameter value is not requested, then the corresponding input values are ignored.

The DIR parameter is only valid if the configured counting direction is set to "User program (internal direction control)".
You determine how to use this parameter in the HSC device configuration.

For an HSC on the CPU or on the SB, the BUSY parameter always has a value of 0.

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10.1 High-speed counter
You configure the parameters for each HSC in the device configuration for the CPU:
counting mode, I/O connections, interrupt assignment, and operation as a high-speed
counter or as a device to measure pulse frequency.
Some of the parameters for the HSC can be modified by your user program to provide
program control of the counting process:
● Set the counting direction to a NEW_DIR value
● Set the current count value to a NEW_CV value
● Set the reference value to a NEW_RV value
● Set the period value (for frequency measurement mode) to a NEW_PERIOD value
If the following Boolean flag values are set to 1 when the CTRL_HSC instruction is executed,
the corresponding NEW_xxx value is loaded to the counter. Multiple requests (more than
one flag is set at the same time) are processed in a single execution of the CTRL_HSC
instruction.
● DIR = 1 is a request to load a NEW_DIR value, 0 = no change
● CV = 1 is a request to load a NEW_CV value, 0 = no change
● RV = 1 is a request to load a NEW_RV value, 0 = no change
● PERIOD = 1 is a request to load a NEW_PERIOD value, 0 = no change
The CTRL_HSC instruction is typically placed in a hardware interrupt OB that is executed
when the counter hardware interrupt event is triggered. For example, if a CV=RV event
triggers the counter interrupt, then a hardware interrupt OB code block executes the
CTRL_HSC instruction and can change the reference value by loading a NEW_RV value.
The current count value is not available in the CTRL_HSC parameters. The process image
address that stores the current count value is assigned during the hardware configuration of
the high-speed counter. You may use program logic to directly read the count value. The
value returned to your program will be a correct count for the instant in which the counter
was read. The counter will continue to count high-speed events. Therefore, the actual count
value could change before your program completes a process using an old count value.
Condition codes: In the case of an error, ENO is set to 0, and the STATUS output contains a
condition code.
Table 10- 3

STATUS values (W#16#)

STATUS
0

Description
No error

80A1

HSC identifier does not address a HSC

80B1

Illegal value in NEW_DIR

80B2

Illegal value in NEW_CV

80B3

Illegal value in NEW_RV

80B4

Illegal value in NEW_PERIOD

80C0

Multiple access to the high-speed counter

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10.1 High-speed counter

10.1.1

Operation of the high-speed counter
The high-speed counter (HSC) counts events that occur faster than the OB execution rate. If
the events to be counted occur within the execution rate of the OB, you can use CTU, CTD,
or CTUD counter instructions. If the events occur faster than the OB execution rate, then use
the HSC. The CTRL_HSC instruction allows your user program to programmatically change
some of the HSC parameters.
For example: You can use the HSC as an input for an incremental shaft encoder. The shaft
encoder provides a specified number of counts per revolution and a reset pulse that occurs
once per revolution. The clock(s) and the reset pulse from the shaft encoder provide the
inputs to the HSC.
The HSC is loaded with the first of several presets, and the outputs are activated for the time
period where the current count is less than the current preset. The HSC provides an interrupt
when the current count is equal to preset, when reset occurs, and also when there is a
direction change.
As each current-count-value-equals-preset-value interrupt event occurs, a new preset is
loaded and the next state for the outputs is set. When the reset interrupt event occurs, the
first preset and the first output states are set, and the cycle is repeated.
Since the interrupts occur at a much lower rate than the counting rate of the HSC, precise
control of high-speed operations can be implemented with relatively minor impact to the scan
cycle of the CPU. The method of interrupt attachment allows each load of a new preset to be
performed in a separate interrupt routine for easy state control. (Alternatively, all interrupt
events can be processed in a single interrupt routine.)

Table 10- 4

Maximum frequency (KHz)

HSC
HSC1

HSC2

Single phase

Two phase and AB quadrature

CPU

100 KHz

80 KHz

High-speed SB

200 KHz

160 KHz

30 KHz

20 KHz

CPU

100 KHz

80 KHz

High-speed SB

200 KHz

160 KHz

30 KHz

20 KHz

HSC3

CPU

100 KHz

80 KHz

HSC4

CPU

30 KHz

20 KHz

HSC5

CPU

30 KHz

20 KHz

High-speed SB

200 KHz

160 KHz

30 KHz

20 KHz

CPU

30 KHz

20 KHz

High-speed SB

200 KHz

160 KHz

30 KHz

20 KHz

HSC6

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10.1 High-speed counter

Selecting the functionality for the HSC
All HSCs function the same way for the same counter mode of operation. There are four
basic types of HSC:
● Single-phase counter with internal direction control
● Single-phase counter with external direction control
● Two-phase counter with 2 clock inputs
● A/B phase quadrature counter
You can use each HSC type with or without a reset input. When you activate the reset input
(with some restrictions, see the following table), the current value is cleared and held clear
until you deactivate the reset input.
● Frequency function: Some HSC modes allow the HSC to be configured (Type of
counting) to report the frequency instead of a current count of pulses. Three different
frequency measuring periods are available: 0.01, 0.1, or 1.0 seconds.
The frequency measuring period determines how often the HSC calculates and reports a
new frequency value. The reported frequency is an average value determined by the total
number of counts in the last measuring period. If the frequency is rapidly changing, the
reported value will be an intermediate between the highest and lowest frequency
occurring during the measuring period. The frequency is always reported in Hertz (pulses
per second) regardless of the frequency-measuring-period setting.
● Counter modes and inputs: The following table shows the inputs used for the clock,
direction control, and reset functions associated with the HSC.
The same input cannot be used for two different functions, but any input not being used
by the present mode of its HSC can be used for another purpose. For example, if HSC1
is in a mode that uses built-in inputs but does not use the external reset (I0.3), then I0.3
can be used for edge interrupts or for HSC2.
Table 10- 5

Counting modes for HSC

Type

Input 1

Input 2

Input 3

Function

Single-phase counter with internal
direction control

Clock

(Optional:
direction)

Count or frequency

Reset

Count

Single-phase counter with external
direction control

Clock

Direction

Count or frequency

Reset

Count

Two-phase counter with 2 clock
inputs

Clock up

Count or frequency

Reset

Count

A/B-phase quadrature counter

Phase A

Count or frequency

Reset1

Count

Clock down
Phase B

For an encoder: Phase Z, Home

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10.1 High-speed counter

Input addresses for the HSC
Note
The digital I/O points used by high-speed counter devices are assigned during device
configuration. When digital I/O point addresses are assigned to these devices, the values of
the assigned I/O point addresses cannot be modified by the force function in a watch table.
When you configure the CPU, you have the option to enable and configure each HSC. The
CPU automatically assigns the input addresses for each HSC according to its configuration.
(Some of the HSCs allow you to select whether to use either the on-board inputs of the CPU
or the inputs of an SB.)
NOTICE
As shown in the following tables, the default assignments for the optional signals for the
different HSCs overlap. For example, the optional external reset for HSC 1 uses the same
input as one of the inputs for HSC 2.
Always ensure that you have configured your HSCs so that any one input is not being used
by two HSCs.
The following table shows the HSC input assignments for both the on-board I/O of the CPU
1211C and an SB. (If the SB has only 2 inputs, only 4.0 and 4.1 inputs are available.)
● For single-phase: C is the Clock input, [d] is the optional direction input, and [R] is an
optional external reset input. (Reset is available only for "Counting" mode.)
● For two-phase: CU is the Clock Up input, CD is the Clock Down input, and [R] is an
optional external reset input. (Reset is available only for "Counting" mode.)
● For AB-phase quadrature: A is the Clock A input, B is the Clock B input, and [R] is an
optional external reset input. (Reset is available only for "Counting" mode.)
Table 10- 6

HSC input assignments for CPU 1211C

HSC

CPU on-board input (0.x)

HSC 1 1

1-phase

[d]

[R]

[d]

[R]

2-phase

[R]

AB-phase
HSC 2 1

HSC 3

HSC 5

[R]

1-phase

[R]

[d]

[R]

[d]

2-phase

[R]

AB-phase

[R]

1-phase

[d]

2-phase

AB-phase
2

SB input (default 4.x) 3

1-phase

[d]

[R]

2-phase

[R]

AB-phase
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10.1 High-speed counter

HSC

CPU on-board input (0.x)
0

HSC 6 2

SB input (default 4.x) 3
1

1-phase

[R]

[d]

2-phase

[R]

AB-phase

[R]

HSC 1 and HSC 2 can be configured for either the on-board inputs or for an SB.

HSC 5 and HSC 6 are available only with an SB. HSC 6 is available only with a 4-input SB.

An SB with only 2 digital inputs provides only the 4.0 and 4.1 inputs.

The following table shows the HSC input assignments for both the on-board I/O of the CPU
1212C and an SB. (If the SB has only 2 inputs, only 4.0 and 4.1 inputs are available.)
● For single-phase: C is the Clock input, [d] is the optional direction input, and [R] is an
optional external reset input. (Reset is available only for "Counting" mode.)
● For two-phase: CU is the Clock Up input, CD is the Clock Down input, and [R] is an
optional external reset input. (Reset is available only for "Counting" mode.)
● For AB-phase quadrature: A is the Clock A input, B is the Clock B input, and [R] is an
optional external reset input. (Reset is available only for "Counting" mode.)
Table 10- 7

HSC input assignments for CPU 1212C

HSC

CPU on-board input (0.x)
0

HSC 1

HSC 3

HSC 5

[d]

[R]

[d]

[R]

1-phase

[R]

[d]

[R]

[d]

2-phase

[R]

AB-phase

[R]

1-phase

[d]

[R]

2-phase

[R]

1-phase

[R]

[d]

2-phase

[R]

AB-phase

[R]

1-phase

[d]

2-phase

[R]

AB-phase
HSC 6 2

2-phase

AB-phase
HSC 4

1-phase
AB-phase

HSC 2 1

SB input (4.x) 3

[R]

1-phase

[R]

[d]

2-phase

[R]

AB-phase

[R]

HSC 1 and HSC 2 can be configured for either the on-board inputs or for an SB.

HSC 5 and HSC 6 are available only with an SB. HSC 6 is available only with a 4-input SB.

An SB with only 2 digital inputs provides only the 4.0 and 4.1 inputs.

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10.1 High-speed counter
The following two tables show the HSC input assignments for the on-board I/O of the CPU
1214C and for an optional SB, if installed.
● For single-phase: C is the Clock input, [d] is the optional direction input, and [R] is an
optional external reset input. (Reset is available only for "Counting" mode.)
● For two-phase: CU is the Clock Up input, CD is the Clock Down input, and [R] is an
optional external reset input. (Reset is available only for "Counting" mode.)
● For AB-phase quadrature: A is the Clock A input, B is the Clock B input, and [R] is an
optional external reset input. (Reset is available only for "Counting" mode.)
Table 10- 8

HSC input assignments for CPU 1214C (on-board inputs only)

HSC
HSC

Digital input 0 (default: 0.x)
11

1-phase

[d]

[R]

2-phase

[R]

1-phase

[d]

[R]

2-phase

[R]

1-phase

[R]
C

[d]

[R]

2-phase

[R]

AB-phase
HSC

HSC 3

1-phase

[R]

[d]

2-phase

[R]

AB-phase

[R]

HSC 51

1-phase

[d]

[R]

2-phase

[R]

AB-phase
HSC 4

Digital input 1 (default: 1.x)

1-phase

[R]

[d]

2-phase

[R]

AB-phase

[R]

AB-phase
HSC 61

AB-phase
1

HSC 1, HSC 2, HSC 5 and HSC 6 can be configured for either the on-board inputs or for an SB.

Table 10- 9

HSC input assignments for SBs

HSC 1

SB inputs (default: 4.x) 2
0

HSC 1

1-phase

[d]

[R]

2-phase

[R]

AB-phase
HSC 2

1-phase

[R]

[d]

2-phase

[R]

AB-phase

[R]

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10.1 High-speed counter

HSC 1
HSC 5

SB inputs (default: 4.x) 2
0

1-phase

[d]

[R]

2-phase

[R]

AB-phase
HSC 6

[R]

1-phase

[R]

[d]

2-phase

[R]

AB-phase

[R]

For CPU 1214C: HSC 1, HSC 2, HSC 5 and HSC 6 can be configured for either the on-board
inputs or for an SB.

An SB with only 2 digital inputs provides only the 4.0 and 4.1 inputs.

Accessing the current value for the HSC
Note
When you enable a pulse generator for use as a PTO, a corresponding HSC is assigned to
this PTO. HSC1 is assigned for PTO1, and HSC2 is assigned for PTO2. The assigned HSC
belongs completely to the PTO channel, and the ordinary output of the HSC is disabled. The
HSC value is only used for the internal functionality. You cannot monitor the current value
(for example, in ID1000) when pulses are occurring.
The CPU stores the current value of each HSC in an input (I) address. The following table
shows the default addresses assigned to the current value for each HSC. You can change
the I address for the current value by modifying the properties of the CPU in the Device
Configuration.
Table 10- 10 Current value of the HSC
HSC

Data type

Default address

HSC1

DInt

ID1000

HSC2

DInt

ID1004

HSC3

DInt

ID1008

HSC4

DInt

ID1012

HSC5

DInt

ID1016

HSC6

DInt

ID1020

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10.1 High-speed counter

10.1.2

Configuration of the HSC
The CPU allows you to configure up to 6 high-speed
counters. You edit the "Properties" of the CPU to
configure the parameters of each individual HSC.
Use the CTRL_HSC instruction in your user program to
control the operation of the HSC.
Enable the specific HSC by selecting the "Enable" option
for that HSC.

After enabling the HSC, configure the other parameters, such as counter function, initial
values, reset options and interrupt events.

For information about configuring the HSC, refer to the section on configuring the CPU
(Page 107).

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10.2 PID control

10.2

PID control
STEP 7 provides the following PID instructions for the S7-1200 CPU:
● The PID_Compact instruction is used to control technical processes with continuous
input- and output variables.
● The PID_3Step instruction is used to control motor-actuated devices, such as valves that
require discrete signals for open- and close actuation.
Both PID instructions (PID_3Step and PID_Compact) can calculate the P-, I-, and Dcomponents during startup (if configured for "pretuning"). You can also configure the
instruction for "fine tuning" to allow you to optimize the parameters. You do not need to
manually determine the parameters.
Note
Execute the PID instruction at constant intervals of the sampling time (preferably in a cyclic
OB).
Because the PID loop needs a certain time to respond to changes of the control value, do
not calculate the output value in every cycle. Do not execute the PID instruction in the main
program cycle OB (such as OB 1).
The sampling time of the PID algorithm represents the time between two calculations of the
output value (control value). The output value is calculated during self-tuning and rounded to
a multiple of the cycle time. All other functions of PID instruction are executed at every call.

PID algorithm
The PID (Proportional/Integral/Derivative) controller measures the time interval between two
calls and then evaluates the results for monitoring the sampling time. A mean value of the
sampling time is generated at each mode changeover and during initial startup. This value is
used as reference for the monitoring function and is used for calculation. Monitoring includes
the current measuring time between two calls and the mean value of the defined controller
sampling time.
The output value for the PID controller consists of three components:
● P (proportional): When calculated with the "P" component, the output value is proportional
to the difference between the setpoint and the process value (input value).
● I (integral): When calculated with the "I" component, the output value increases in
proportion to the duration of the difference between the setpoint and the process value
(input value) to finally correct the difference.
● D (derivative): When calculated with the "D" component, the output value increases as a
function of the increasing rate of change of the difference between the setpoint and the
process value (input value). The output value is corrected to the setpoint as quickly as
possible.
The PID controller uses the following formula to calculate the output value for the
PID_Compact instruction.

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10.2 PID control

y = Kp

[ (b · w - x) + T · s

(w - x) +

TD · s
a · TD · s + 1

(c · w - x)

]

Output value

Process value

Setpoint value

Laplace operator

Proportional gain
(P component)

Derivative delay coefficient
(D component)

Integral action time
(I component)

Proportional action weighting
(P component)

Derivative action time
(D component)

Derivative action weighting
(D component)

The PID controller uses the following formula to calculate the output value for the PID_3Step
instruction.

[

Δ y = K p · s · (b · w - x) +

10.2.1

1
TI · s

(w - x) +

TD · s
a · TD · s + 1

(c · w - x)

]

Output value

Process value

Setpoint value

Laplace operator

Proportional gain
(P component)

Derivative delay coefficient
(D component)

Integral action time
(I component)

Proportional action weighting
(P component)

Derivative action time
(D component)

Derivative action weighting
(D component)

Inserting the PID instruction and technological object
STEP 7 provides two instructions for PID control:
● The PID_Compact instruction and its associated technological object provide a universal
PID controller with tuning. The technological object contains all of the settings for the
control loop.
● The PID_3Step instruction and its associated technological object provide a PID
controller with specific settings for motor-activated valves. The technological object
contains all of the settings for the control loop. The PID_3Step controller provides two
additional Boolean outputs.
After creating the technological object, you must configure the parameters (Page 309). You
also adjust the autotuning parameters ("pretuning" during startup or manual "fine tuning") to
commission the operation of the PID controller (Page 311).

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10.2 PID control
Table 10- 11 Inserting the PID instruction and the technological object
When you insert a PID instruction into your user program,
STEP 7 automatically creates a technology object and an
instance DB for the instruction. The instance DB contains
all of the parameters that are used by the PID instruction.
Each PID instruction must have its own unique instance
DB to operate properly.
After inserting the PID instruction and creating the
technological object and instance DB, you configure the
parameters for the technological object (Page 309).

Table 10- 12 (Optional) Creating a technological object from the project navigator
You can also create technological objects for your
project before inserting the PID instruction. By
creating the technological object before inserting a
PID instruction into your user program, you can
then select the technological object when you insert
the PID instruction.

To create a technological object, double-click the
"Add new object" icon in the project navigator.

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10.2 PID control
Click the "Control" icon and select the technological
object for the type of PID controller (PID_Compact
or PID_3Step). You can create an optional name
for the technological object.
Click "OK" to create the technological object.

10.2.2

PID_Compact instruction

Table 10- 13 PID_Compact instruction
LAD / FBD

Description
PID_Compact provides a PID controller with self-tuning for automatic and manual mode.
PID_Compact is a PIDT1 controller with anti-windup and weighting of the P- and Dcomponent.

STEP 7 automatically creates the technological object and instance DB when you insert the instruction. The instance
DB contains the parameters of the technological object.

The PID controller uses the following formula to calculate the output value for the
PID_Compact instruction.

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10.2 PID control

y = Kp

[ (b · w - x) + T · s

(w - x) +

TD · s
a · TD · s + 1

(c · w - x)

]

Output value

Process value

Setpoint value

Laplace operator

Proportional gain
(P component)

Derivative delay coefficient
(D component)

Integral action time
(I component)

Proportional action weighting
(P component)

Derivative action time
(D component)

Derivative action weighting
(D component)

Table 10- 14 Data types for the parameters
Parameter and type

Data type

Description

Setpoint

Real

Setpoint of the PID controller in automatic mode. Default value: 0.0

Input

Real

Process value. Default value: 0.0
You must also set sPid_Cmpt.b_Input_PER_On = FALSE.

Input_PER

Word

Analog process value (optional). Default value: W#16#0

ManualEnable

Bool

Enables or disables the manual operation mode. Default value: FALSE

You must also set sPid_Cmpt.b_Input_PER_On = TRUE.

ManualValue

Real

Reset

Bool



On the edge of the change from FALSE to TRUE, the PID controller
switches to manual mode, State = 4, and sRet.i_Mode remains
unchanged.



On the edge of the change from TRUE to FALSE, the PID controller
switches to the last active operating mode and State = sRet.i_Mode.

Process value for manual operation. Default value: 0.0
Restarts the controller. Default value: FALSE
If Reset = TRUE, the following applies:


Inactive operating mode



Input value = 0



Integral part of the process value = 0



Intermediate values of the system are reset (PIDParameter is
retained)

ScaledInput

OUT

Real

Scaled process value. Default value: 0.0

Output1

OUT

Real

Output value. Default value: 0.0

Output_PER1

OUT

Word

Analog output value. Default value: W#16#0

Output_PWM1

OUT

Bool

Output value for pulse width modulation. Default value: FALSE

SetpointLimit_H

OUT

Bool

Setpoint high limit. Default value: FALSE
If SetpointLimit_H = TRUE, the absolute upper limit of the setpoint is
reached. Default value: FALSE

SetpointLimit_L

OUT

Bool

Setpoint low limit. Default value: FALSE
If SetpointLimit_L = TRUE, the absolute lower limit of the setpoint is
reached. Default value: FALSE

InputWarning_H

OUT

Bool

If InputWarning_H = TRUE, the process value reached or exceeded the
upper warning limit. Default value: FALSE

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10.2 PID control

Parameter and type

Data type

Description

InputWarning_L

OUT

Bool

If InputWarning_L = TRUE, the process value reached the lower
warning limit. Default value: FALSE

State

OUT

Int

Current operating mode of the PID controller. Default value: 0
Use sRet.i_Mode to change the mode.

Error
1

OUT

DWord



State = 0: Inactive



State = 1: Pretuning



State = 2: Manual fine tuning



State = 3: Automatic mode



State = 4: Manual mode

Error message Default value: DW#16#0000 (no error)

The outputs of the Output, Output_PER, and Output_PWM parameters can be used in parallel.
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10.2 PID control

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Figure 10-2

10.2.3

Operation of the PID_Compact controller as a PIDT1 controller with anti-windup

PID_3STEP instruction

Table 10- 15 PID_3Step instruction
LAD / FBD

Description
PID_3Step configures a PID controller with self-tuning capabilities that has been optimized
for motor-controlled valves and actuators. It provides two Boolean outputs.
PID_3Step is a PIDT1controller with anti-windup and weighting of the P- and Dcomponents.

STEP 7 automatically creates the technological object and instance DB when you insert the instruction. The instance
DB contains the parameters of the technological object.

The PID controller uses the following formula to calculate the output value for the PID_3Step
instruction.

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10.2 PID control

[

Δ y = K p · s · (b · w - x) +

1
TI · s

(w - x) +

TD · s
a · TD · s + 1

(c · w - x)

]

Output value

Process value

Setpoint value

Laplace operator

Proportional gain
(P component)

Derivative delay coefficient
(D component)

Integral action time
(I component)

Proportional action weighting
(P component)

Derivative action time
(D component)

Derivative action weighting
(D component)

Table 10- 16 Data types for the parameters
Parameter and type

Data type

Description

Setpoint

Real

Setpoint of the PID controller in automatic mode. Default value: 0.0

Input

Real

Process value. Default value: 0.0
You must also set Config.InputPEROn = FALSE.

Input_PER

Word

Analog process value (optional). Default value: W#16#0

ManualEnable

Bool

Enables or disables the manual operation mode. Default value: FALSE

You must also set Config.InputPEROn = TRUE.

ManualUP

ManualDN

ManualValue

Bool

Real



On the edge of the change from FALSE to TRUE, the PID controller
switches to manual mode, State = 4, and Retain.Mode remains
unchanged.



On the edge of the change from TRUE to FALSE, the PID controller
switches to the last active operating mode and
State = Retain.Mode.

In manual mode, every rising edge opens the valve by 5% of the total
actuating range, or for the duration of the minimum motor actuation
time. ManualUP is evaluated only if you are using OutputPer and if
position feedback is available. Default value: FALSE


If Output_PER is FALSE, the manual input turns Output_UP on for
the time that corresponds to a movement of 5% of the device.



If Config.ActuatorEndStopOn is TRUE, then Output_UP does not
come on if Actuator_H is TRUE.

In manual mode, every rising edge closes the valve by 5% of the total
actuating range, or for the duration of the minimum motor actuation
time. ManualDN is evaluated only if you are using OutputPer and if
position feedback is available. Default value: FALSE


If Output_PER is FALSE, the manual input turns Output_DN on for
the time that corresponds to a movement of 5% of the device.



If Config.ActuatorEndStopOn is TRUE, then Output_DN does not
turn on if Actuator_L is TRUE.

Process value for manual operation. Default value: 0.0
In manual mode, you specify the absolute position of the valve.
ManualValue is evaluated only if you are using OutputPer, or if position
feedback is available. Default value: 0.0

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Parameter and type

Data type

Description

Feedback

Real

Position feedback of the valve. Default value: 0.0

Feedback_PER

Word

To use Feedback, then set Config.FeedbackPerOn = FALSE.
Analog feedback of the valve position. Default value: W#16#0
To use Feedback_PER, set Config.FeedbackPerOn = TRUE.
Feedback_PER is scaled, using the following parameters:


Config.FeedbackScaling.LowerPointIn



Config.FeedbackScaling.UpperPointIn



Config.FeedbackScaling.LowerPointOut



Config.FeedbackScaling.UpperPointOut

Actuator_H

Bool

If Actuator_H = TRUE, the valve is at the upper end stop and is no
longer moved in this direction. Default value: FALSE

Actuator_L

Bool

If Actuator_L = TRUE, the valve is at the lower end stop and is no
longer moved in this direction. Default value: FALSE

Reset

Bool

Restarts the PID controller. Default value: FALSE
If Reset = TRUE:


"Inactive" operating mode



Input value = 0



Interim values of the controller are reset. (PID parameters are
retained.)

ScaledInput

OUT

Real

Scaled process value

ScaledFeedback

OUT

Real

Scaled valve position

Output_PER

OUT

Word

Analog output value. If Config.OutputPerOn = TRUE, then Output_PER
is evaluated.

Output_UP

OUT

Bool

Digital output value for opening the valve. Default value: FALSE
If Config.OutputPerOn = FALSE, then parameter Output_UP is
evaluated.

Output_DN

OUT

Bool

Digital output value for closing the valve. Default value: FALSE
If Config.OutputPerOn = FALSE, then parameter Output_DN is
evaluated.

SetpointLimitH

OUT

Bool

Setpoint high limit. Default value: FALSE
If SetpointLimitH = TRUE, the absolute upper limit of the setpoint is
reached. In the CPU, the setpoint is limited to the configured absolute
upper limit of the actual value.

SetpointLimitL

OUT

Bool

Setpoint low limit. Default value: FALSE
If SetpointLimitL = TRUE, the absolute lower limit of the setpoint is
reached. In the CPU the setpoint is limited to the configured absolute
lower limit of the actual value.

InputWarningH

OUT

Bool

If InputWarningH = TRUE, the input value has reached or exceeded the
upper warning limit. Default value: FALSE

InputWarningL

OUT

Bool

If InputWarningL = TRUE, the input value has reached or exceeded the
lower warning limit. Default value: FALSE

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Parameter and type
State

OUT

Data type

Description

Int

Current operating mode of the PID controller. Default value: 0
Use Retain.Mode to change the operating mode:


State = 0: Inactive



State = 1: Pretuning



State = 2: Manual fine tuning



State = 3: Automatic mode



State = 4: Manual mode



State = 5: Safety mode



State = 6: Output value measurement



State = 7: Safety mode monitoring with active trigger



State = 8: Inactive mode monitoring with active trigger

Error

OUT

Bool

If Error = TRUE, at least one error message is pending. Default value:
FALSE

ErrorBits

OUT

DWord

Error message. Default value: DW#16#0000 (no error)

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10.2 PID control
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10.2 PID control
If several errors are pending, the values of the error codes are displayed by means of binary
addition. The display of error code 0003, for example, indicates that the errors 0001 and
0002 are also pending.
Table 10- 17 ErrorBit parameters
ErrorBit (DW#16#...)

Description

0000

No error

0001

The Input parameter is outside the limits of the process value.


Input > Config.InputUpperLimit or



Input < Config.InputLowerLimit

0002

Invalid value for the "Input_PER" parameter. Determine whether there is an error at the
analog input.

0004

Fine tuning: Oscillation of the process value (input) could not be maintained.

0008

Pretuning: The process value (input) is too close to the setpoint. Start the fine tuning.

0010

The setpoint must not be changed during pretuning at the operating point.

0020

Pretuning is set to automatic mode, which is not allowed during fine tuning.

0040

Pretuning: The setpoint is too close to the limits for the output value.

0080

Pretuning: Incorrect configuration of the limits for the output value.

0100

An error during fine tuning: resulted in invalid parameters.

0200

0400

Invalid value for the Input parameter:


Value outside the number range (less than -1e12 or greater than 1e12)



Value with invalid number format

Invalid value for the Output parameter:


Value outside the number range (less than -1e12 or greater than 1e12)



Value with invalid number format

800

Sampling time error: The PID_3STEP instruction is called in a program cycle OB (such as
OB 1), or the settings were changed for the cyclic interrupt OB.

1000

Invalid value for the Setpoint parameter:


Value outside the number range (less than -1e12, or greater than 1e12)



Value with invalid number format

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10.2.4

Configuring the PID controller
The parameters of the technological object determine the operation of the PID
controller. Use the icon to open the configuration editor.

Figure 10-6

Configuration editor for PID_Compact (Basic settings)

Table 10- 18 Sample configuration settings for the PID_Compact instruction
Settings
Basic

Process
value

Description
Controller type

Selects the engineering units.

Invert the control logic

Allows selection of a reverse-acting PID loop.


If not selected, the PID loop is in direct-acting mode and the output of PID loop
increases if input value < setpoint.



If selected, the output of the PID loop increases if the input value > setpoint.

Enable last mode after
CPU restart

Restarts the PID loop after it is reset or if an input limit has been exceeded and
returned to the valid range.

Input

Selects either the Input parameter or the Input_PER parameter (for analog) for the
process value. Input_PER can come directly from an analog input module.

Output

Selects either the Output parameter or the Output_PER parameter (for analog) for
the output value. Output_PER can go directly to an analog output module.

Scales both the range and the limits for the process value. If the process value goes below the low limit or
above the high limit, the PID loop goes to inactive mode and sets the output value to 0.
To use Input_PER, you must scale the analog process value (input value).

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Figure 10-7

Configuration editor for PID_3Step (Basic settings)

Table 10- 19 Sample configuration settings for the PID_3Step instruction
Settings
Basic

Process
value

Description
Controller type

Selects the engineering units.

Invert the control logic

Allows selection of a reverse-acting PID loop.


If not selected, the PID loop is in direct-acting mode, and the output of PID loop
increases if the input value < setpoint).



If selected, the output of the PID loop increases if the input value > setpoint.

Enable last mode after
CPU restart

Restarts the PID loop after it is reset or if an input limit has been exceeded and
returned to the valid range.

Input

Selects either the Input parameter or the Input_PER parameter (for analog) for the
process value. Input_PER can come directly from an analog input module.

Output

Selects either to use the digital outputs (Output_UP and Output_DN) or to use the
analog output (Output_PER) for the output value.

Feedback

Selects the type of device status returned to the PID loop:


No feedback (default)



Feedback



Feedback_PER

Actuator

Motor transition
time

Sets the time from open to close for the valve. (Locate this value on the data sheet or
the faceplate of the valve.)

Minimum ON time

Sets the minimum movement time for the valve. (Locate this value on the data sheet or
the faceplate of the valve.)

Minimum OFF
time

Sets the minimum pause time for the valve. (Locate this value on the data sheet or the
faceplate of the valve.)

Error behavior

Defines the behavior of the valve when an error is detected or when the PID loop is
reset. If you select to use a substitute position, enter the "Safety position". For analog
feedback or analog output, select a value between the upper or lower limit for the
output. For digital outputs, you can choose only 0% (off) or 100% (on).

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Settings

Description
Scale Position
Feedback1



"High stop" and "Lower limit stop" define the maximum positive position (full-open)
and the maximum negative position (full-closed). "High stop" must be greater than
"Lower limit stop".



"High limit process value" and "Low limit process value" define the upper and lower
positions of the valve during tuning and automatic mode.



"FeedbackPER" ("Low" and "High") defines the analog feedback of the valve
position. "FeedbackPER High" must be greater than "FeedbackPER Low".

"Scale Position Feedback" is editable only if you enabled "Feedback" in the "Basic" settings.

10.2.5

Commissioning the PID controller
Use the commissioning editor to configure the PID controller for autotuning at startup
and for autotuning during operation. To open the commissioning editor, click the icon
on either the instruction or the project navigator.

Table 10- 20 Sample configuration screen (PID_3Step)


Measurement: To display the setpoint, the
process value (input value) and the output value in a
real-time trend, enter the sample time and click the
"Start" button.



Tuning mode: To tune the PID loop, select either
"Pretuning" or "Fine tuning" (manual) and click the
"Start" button. The PID controller runs through
multiple phases to calculate system response and
update times. The appropriate tuning parameters are
calculated from these values.

After the completion of the tuning process, you can
store the new parameters by clicking the "Upload PID
parameters" button in the "PID Parameters" section of
the commissioning editor.
If an error occurs during tuning, the output value of the
PID goes to 0. The PID mode then is set to "inactive"
mode. The status indicates the error.

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10.3 Basic motion control

10.3

Basic motion control
The CPU provides motion control functionality for the operation of stepper motors and servo
motors with pulse interface. The motion control functionality takes over the control and
monitoring of the drives.
● The "Axis" technology object configures the mechanical drive data, drive interface,
dynamic parameters, and other drive properties.
● You configure the pulse and direction outputs of the CPU for controlling the drive.
● Your user program uses the motion control instructions to control the axis and to initiate
motion tasks.
● Use the PROFINET interface to establish the online connection between the CPU and
the programming device. In addition to the online functions of the CPU, additional
commissioning and diagnostic functions are available for motion control.

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Power section for stepper motor
Power section for servo motor

The DC/DC/DC variants of the CPU S7-1200 have onboard
outputs for direct control of drives. The relay variants of the
CPU require the signal board with DC outputs for drive
control.

A signal board (SB) expands the onboard I/O to include a few additional I/O points. An SB
with 2 digital outputs can be used as pulse and direction outputs to control one motor. An SB
with 4 digital outputs can be used as pulse and direction outputs to control two motors. Builtin relay outputs cannot be used as pulse outputs to control motors.
Note
Pulse-train outputs cannot be used by other instructions in the user program
When you configure the outputs of the CPU or signal board as pulse generators (for use with
the PWM or basic motion control instructions), the corresponding output addresses (Q0.0 to
Q0.3, Q4.0 to Q4.3) are removed from the Q memory and cannot be used for other purposes
in your user program. If your user program writes a value to an output used as a pulse
generator, the CPU does not write that value to the physical output.

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Table 10- 21 Maximum number of controllable drives
Type of CPU
CPU 1211C

CPU 1212C

CPU 1214C

No SB installed

With an SB
(2 x DC outputs)

With an SB
(4 x DC outputs)

DC/DC/DC

AC/DC/RLY

DC/DC/RLY

DC/DC/DC

AC/DC/RLY

DC/DC/RLY

DC/DC/DC

AC/DC/RLY

DC/DC/RLY

Table 10- 22 Limit frequencies of pulse outputs
Pulse output

Frequency

Onboard

2 Hz ≤ f ≤ 100 KHz

Standard SB

2 Hz ≤ f ≤ 20 KHz

High-speed (200 KHz) SBs

MC V2 instructions: 2 Hz ≤ f ≤ 200 KHz
MC V1 instructions: 2 Hz ≤ f ≤ 100 KHz 1

MC V1 instructions support a maximum frequency of 100 KHz.

NOTICE
The maximum pulse frequency of the pulse output generators is 100 KHz for the digital
outputs of the CPU, 20 KHz for the digital outputs of the standard SB, and 200 KHz for the
digital outputs of the high-speed SBs (or 100 KHz for MC V1 instructions). However,
STEP 7 does not alert you when you configure an axis with a maximum speed or frequency
that exceeds this hardware limitation. This could cause problems with your application, so
always ensure that you do not exceed the maximum pulse frequency of the hardware.
1. Configure a pulse generator: Select the "Pulse generators (PTO/PWM)" properties for a
CPU (in Device configuration) and enable a pulse generator. Two pulse generators are
available for each S7-1200 CPU. In this same configuration area under "Pulse options",
select Pulse generator used as: "PTO".

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2. Add a Technological object:
– In the Project tree, expand the node "Technological Objects" and select "Add new
object".
– Select the "Axis" icon (rename if required) and click "OK" to open the configuration
editor for the axis object.
– Display the "Select PTO for Axis Control" properties under the "Basic parameters" and
select the configured PTO. Note the two Q outputs assigned for pulse and direction.
– Configure the remaining Basic and Extended parameters.
3. Program your application: Insert the MC_Power instruction in a code block.
– For the Axis input, select the axis technology object that you created and configured.
– Setting the Enable input to TRUE allows the other motion instructions to function.
– Setting the Enable input FALSE cancels the other motion instructions.
Note
Include only one MC_Power instruction per axis.
4. Insert the other motion instructions to produce the required motion.
Note
The CPU calculates motion tasks in "slices" or segments of 10 ms. As one slice is being
executed, the next slice is waiting in the queue to be executed. If you interrupt the motion
task on an axis (by executing another new motion task for that axis), the new motion task
may not be executed for a maximum of 20 ms (the remainder of the current slice plus the
queued slice).

10.3.1

Configuration of the axis
STEP 7 provides the configuration tools, the commissioning tools, and the diagnostic tools
for the "Axis" technological object.

①
②
③

Drive
Technological object

④
⑤

Commissioning
Diagnostics

Configuration

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Note
The PTO requires the internal functionality of a high-speed counter (HSC). This means the
corresponding high-speed counter cannot be used elsewhere.
The assignment between PTO and HSC is fixed. When PTO1 is activated, it will be
connected to HSC1. If PTO2 is activated, it will be connected to HSC2.
You cannot monitor the current value (for example, in ID 1000) when pulses are occurring.

Table 10- 23 STEP 7 tools for motion control
Tool

Description

Configuration

Configures the following properties of the "Axis" technology object:


Selection of the PTO to be used and configuration of the drive interface



Properties of the mechanics and the transmission ratio of the drive (or machine or system)

 Properties for position limits, dynamics, and homing
Save the configuration in the data block of the technology object.
Commissioning

Tests the function of your axis without having to create a user program. When the tool is started,
the control panel will be displayed. The following commands are available on the control panel:


Enable and disable axis



Move axis in jog mode



Position axis in absolute and relative terms



Home axis

 Acknowledge errors
The velocity and the acceleration / deceleration can be specified for the motion commands. The
control panel also shows the current axis status.
Diagnostics

Monitors of the current status and error information for the axis and drive.

After you create the technological object for the
axis, you configure the axis by defining the basic
parameters, such as the PTO and the configuration
of the drive interface. You also configure the other
properties of the axis, such as position limits,
dynamics, and homing.

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NOTICE
If you change the dimension system at a later time, the values may not be converted
correctly in all configuration windows of the technology object. In this case, check the
configuration of all axis parameters.
You may have to adapt the values of the input parameters of motion control instructions to
the new dimension unit in the user program.

Configure the properties for the drive signals, drive
mechanics, and position monitoring (hardware and
software limit switches).
Do not deselect the options for a hardware limit or
a reference point configuration unless the input
point is no longer assigned as a hardware limit or a
reference point.
You configure the motion dynamics and the
behavior of the emergency stop command.

You also configure the homing behavior (passive and active).

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Use the "Commissioning" control panel to test the functionality independently from your user
program.
Click the "Startup" icon to commission the axis.
The control panel shows the current status of the axis. Not only can you enable and disable
the axis, but you can also test the positioning of the axis (both in absolute and relative terms)
and can specify the velocity, acceleration and deceleration. You can also test the homing
and jogging tasks. The control panel also allows you to acknowledge errors.

10.3.2

Motion control instructions
Note
The CPU calculates motion tasks in "slices" or segments of 10 ms. As one slice is being
executed, the next slice is waiting in the queue to be executed. If you interrupt the motion
task on an axis (by executing another new motion task for that axis), the new motion task
may not be executed for a maximum of 20 ms (the remainder of the current slice plus the
queued slice).

10.3.2.1

MC_Power instruction
NOTICE
If the axis is switched off due to an error, it will be enabled again automatically after the
error has been eliminated and acknowledged. This requires that the Enable input
parameter has retained the value TRUE during this process.

Table 10- 24 MC_Power instruction
LAD / FBD

Description
The MC_Power motion control instruction enables or disables an axis. Before you can
enable or disable the axis, ensure the following conditions:


The technology object has been configured correctly.

 There is no pending enable-inhibiting error.
The execution of MC_Power cannot be aborted by a motion control task. Disabling the
axis (input parameter Enable = FALSE ) aborts all motion control tasks for the
associated technology object.
1

STEP 7 automatically creates the DB when you insert the instruction.

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Table 10- 25 Parameters for the MC_Power instruction
Parameter and type

Data type

Description

Axis

TO_Axis_1

Axis technology object

Enable

Bool



FALSE (default): All active tasks are aborted according to the
parameterized "StopMode" and the axis is stopped.



TRUE: Motion Control attempts to enable the axis.



0: Emergency stop - If a request to disable the axis is pending, the
axis brakes at the configured emergency deceleration. The axis is
disabled after reaching standstill.

StopMode

Int

1: Immediate stop - If a request to disable the axis is pending, this
axis is disabled without deceleration. Pulse output is stopped
immediately.
Status

OUT

Bool

Status of axis enable:




Busy

OUT

Bool

Error

OUT

Bool

FALSE: The axis is disabled.
–

The axis does not execute motion control tasks and does not
accept any new tasks (exception: MC_Reset task).

–

The axis is not homed.

–

Upon disabling, the status does not change to FALSE until the
axis reaches a standstill.

TRUE: The axis is enabled.
–

The axis is ready to execute motion control tasks.

–

Upon axis enabling, the status does not change to TRUE until
the signal "Drive ready" is pending. If the "Drive ready" drive
interface was not configured in the axis configuration, the status
changes to TRUE immediately.

False: MC_Power is not active.
TRUE: MC Power is active.
FALSE: No error
TRUE: An error has occurred in motion control instruction "MC_Power"
or in the associated technology object. The cause of the error can be
found in parameters "ErrorID" and "ErrorInfo".

ErrorID

OUT

Word

Error ID for parameter "Error""

ErrorInfo

OUT

Word

Error info ID for parameter "ErrorID"

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An axis is enabled and then disabled again. After the drive has signaled "Drive ready" back to the CPU, the
successful enable can be read out via "Status_1".
Following an axis enable, an error has occurred that caused the axis to be disabled. The error is eliminated and
acknowledged with "MC_Reset". The axis is then enabled again.

To enable an axis with configured drive interface, follow these steps:
1. Check the requirements indicated above.
2. Initialize input parameter "StopMode" with the desired value. Set input parameter
"Enable" to TRUE.
The enable output for "Drive enabled" changes to TRUE to enable the power to the drive.
The CPU waits for the "Drive ready" signal of the drive.
When the "Drive ready" signal is available at the configured ready input of the CPU, the
axis becomes enabled. Output parameter "Status" and technology object tag .StatusBits.Enable indicates the value TRUE.
To enable an axis without configured drive interface, follow these steps:
1. Check the requirements indicated above.
2. Initialize input parameter "StopMode" with the desired value. Set input parameter
"Enable" to TRUE. The axis is enabled. Output parameter "Status" and technology object
tag .StatusBits.Enable indicate the value TRUE.
To disable an axis, follow these steps:
1. Bring the axis to a standstill.
You can identify when the axis is at a standstill in technology object tag .StatusBits.StandStill.
2. Set input parameter "Enable" to FALSE after standstill is reached.
3. If output parameters "Busy" and "Status" and technology object tag .StatusBits.Enable indicate the value FALSE, disabling of the axis is complete.

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10.3.2.2

MC_Reset instruction

Table 10- 26 MC_Reset instruction
LAD / FBD

Description
Use the MC_Reset instruction to acknowledge "Operating error with axis stop" and
"Configuration error". The errors that require acknowledgement can be found in the "List
of ErrorIDs and ErrorInfos" under "Remedy".
Before using the MC_Reset instruction, you must have eliminated the cause of a
pending configuration error requiring acknowledgement (for example, by changing an
invalid acceleration value in "Axis" technology object to a valid value).

STEP 7 automatically creates the DB when you insert the instruction.

The MC_Reset task cannot be aborted by any other motion control task. The new MC_Reset
task does not abort any other active motion control tasks.
Table 10- 27 Parameters of the MC_Reset instruction
Parameter and type

Data type

Description

Axis

TO_Axis_1

Axis technology object

Execute

Bool

Start of the task with a positive edge

Done

OUT

Bool

TRUE = Error has been acknowledged.

Busy

OUT

Bool

TRUE = The task is being executed.

Error

OUT

Bool

TRUE = An error has occurred during execution of the task. The
cause of the error can be found in parameters "ErrorID" and
"ErrorInfo".

ErrorID

OUTP

Word

Error ID for parameter "Error""

ErrorInfo

OUT

Word

Error info ID for parameter "ErrorID"

To acknowledge an error with MC_Reset, follow these steps:
1. Check the requirements indicated above.
2. Start the acknowledgement of the error with a rising edge at the Execute input parameter.
3. The error has been acknowledged when Done equals TRUE and the technology object
tag .StatusBits.Error equals FALSE.

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10.3.2.3

MC_Home instruction

Table 10- 28 MC_Home instruction
LAD / FBD

Description
Use the MC_Home instruction to match the axis coordinates to the real, physical drive
position. Homing is required for absolute positioning of the axis:
In order to use the MC_Home instruction, the axis must first be enabled.

STEP 7 automatically creates the DB when you insert the instruction.

The following types of homing are available:
● Direct homing absolute (Mode = 0): The current axis position is set to the value of
parameter "Position".
● Direct homing relative (Mode = 1): The current axis position is offset by the value of
parameter "Position".
● Passive homing (Mode = 2): During passive homing, the MC_Home instruction does not
carry out any homing motion. The traversing motion required for this step must be
implemented by the user via other motion control instructions. When the reference point
switch is detected, the axis is homed.
● Active homing (Mode = 3): The homing procedure is executed automatically.
Table 10- 29 Parameters for the MC_Home instruction
Parameter and type

Data type

Description

Axis

TO_Axis_PTO

Axis technology object

Execute

Bool

Start of the task with a positive edge

Position

Real



Mode = 0, 2, and 3 (Absolute position of axis after completion of the
homing operation)

 Mode = 1 (Correction value for the current axis position)
Limit values: -1.0e12 ≤ Position ≤ 1.0e12

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Parameter and type
Mode

Data type

Description

Int

Homing mode


0: Direct homing absolute
New axis position is the position value of parameter "Position".



1: Direct homing relative
New axis position is the current axis position + position value of
parameter "Position".



2: Passive homing
Homing according to the axis configuration. Following homing, the
value of parameter "Position" is set as the new axis position.



3: Active homing
Reference point approach in accordance with the axis configuration.
Following homing, the value of parameter "Position" is set as the new
axis position.

Done

OUT

Bool

TRUE = Task completed

Busy

OUT

Bool

TRUE = The task is being executed.

CommandAborted

OUT

Bool

TRUE = During execution the task was aborted by another task.

Error

OUT

Bool

TRUE = An error has occurred during execution of the task. The cause
of the error can be found in parameters "ErrorID" and "ErrorInfo".

ErrorID

OUT

Word

Error ID for parameter "Error""

ErrorInfo

OUT

Word

Error info ID for parameter "ErrorID"

Note
Axis homing is lost under the following conditions
 Disabling of axis by the MC_Power instruction
 Switchover between automatic control and manual control
 Upon start of active homing (After successful completion of the homing operation, axis
homing is available again.)
 After power-cycling the CPU
 After CPU restart (RUN-to-STOP or STOP-to-RUN)
To home the axis, follow these steps:
1. Check the requirements indicated above.
2. Initialize the necessary input parameters with values, and start the homing operation with
a rising edge at input parameter "Execute".
3. If output parameter "Done" and technology object tag .StatusBits.HomingDone indicate the value TRUE, homing is complete.

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10.3 Basic motion control
Table 10- 30 Override response
Mode

Description

0 or 1

The MC_Home task cannot be aborted by any other motion control task. The new MC_Home task does not
abort any active motion control tasks. Position-related motion tasks are resumed after homing according to
the new homing position (value at the Position input parameter).

The MC_Home task can be aborted by the following motion control tasks:
MC_Home task Mode = 2, 3: The new MC_Home task aborts the following active motion control task.
MC_Home task Mode = 2: Position-related motion tasks are resumed after homing according to the new
homing position (value at the Position input parameter).

The MC_Home task can be aborted by the following
motion control tasks:

10.3.2.4

The new MC_Home task aborts the following active
motion control tasks:



MC_Home Mode = 3



MC_Home Mode = 2, 3



MC_Halt



MC_Halt



MC_MoveAbsolute



MC_MoveAbsolute



MC_MoveRelative



MC_MoveRelative



MC_MoveVelocity



MC_MoveVelocity



MC_MoveJog



MC_MoveJog

MC_Halt instruction

Table 10- 31 MC_Halt instruction
LAD / FBD

Description
Use the MC_Halt instruction to stop all motion and to brings the axis to a stand-still. The
stand-still position is not defined.
In order to use the MC_Halt instruction, the axis must first be enabled.

STEP 7 automatically creates the DB when you insert the instruction.

Table 10- 32 Parameters for the MC_Halt instruction
Parameter and type

Data type

Description

Axis

TO_Axis_1

Axis technology object

Execute

Bool

Start of the task with a positive edge

Done

OUT

Bool

TRUE = Zero velocity reached

Busy

OUT

Bool

TRUE = The task is being executed.

CommandAborted

OUT

Bool

TRUE = During execution the task was aborted by another
task.

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Parameter and type

Data type

Description

Error

OUT

Bool

TRUE = An error has occurred during execution of the task.
The cause of the error can be found in parameters "ErrorID"
and "ErrorInfo".

ErrorID

OUT

Word

Error ID for parameter "Error"

ErrorInfo

OUT

Word

Error info ID for parameter "ErrorID"

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Deceleration = 5.0

①
②

The axis is braked by an MC_Halt task until it comes to a standstill. The axis standstill is signaled via "Done_2".
While an MC_Halt task is braking the axis, this task is aborted by another motion task. The abort is signaled via
"Abort_2".

Override response
The MC_Halt task can be aborted by the
following motion control tasks:







MC_Home Mode = 3
MC_Halt
MC_MoveAbsolute
MC_MoveRelative
MC_MoveVelocity
MC_MoveJog

The new MC_Halt task aborts the following
active motion control tasks:







MC_Home Mode = 3
MC_Halt
MC_MoveAbsolute
MC_MoveRelative
MC_MoveVelocity
MC_MoveJog

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10.3 Basic motion control

10.3.2.5

MC_MoveAbsolute instruction

Table 10- 33 MC_MoveAbsolute instruction
LAD / FBD

Description
Use the MC_MoveAbsolute instruction to start a positioning motion of the axis to an
absolute position.
In order to use the MC_MoveAbsolute instruction, the axis must first be enabled and
also must be homed.

STEP 7 automatically creates the DB when you insert the instruction.

Table 10- 34 Parameters for the MC_MoveAbsolute instruction
Parameter and type

Data type

Description

Axis

TO_Axis_1

Axis technology object

Execute

Bool

Start of the task with a positive edge (Default value: False)

Position

Real

Absolute target position (Default value: 0.0)
Limit values: -1.0e12 ≤ Position ≤ 1.0e12

Velocity

Real

Velocity of axis (Default value: 10.0)
This velocity is not always reached because of the configured
acceleration and deceleration and the target position to be
approached.
Limit values: Start/stop velocity ≤ Velocity ≤ maximum velocity

Done

OUT

Bool

TRUE = Absolute target position reached

Busy

OUT

Bool

TRUE = The task is being executed.

CommandAborted

OUT

Bool

TRUE = During execution the task was aborted by another task.

Error

OUT

Bool

TRUE = An error has occurred during execution of the task. The
cause of the error can be found in parameters "ErrorID" and
"ErrorInfo".

ErrorID

OUT

Word

Error ID for parameter "Error" (Default value: 0000)

ErrorInfo

OUT

Word

Error info ID for parameter "ErrorID" (Default value: 0000)

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10.3 Basic motion control

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The following values were configured in the "Dynamics > General" configuration window: Acceleration = 10.0 and
Deceleration = 10.0

①

②

An axis is moved to absolute position 1000.0 with a MC_MoveAbsolute task. When the axis reaches the target
position, this is signaled via "Done_1". When "Done_1" = TRUE, another MC_MoveAbsolute task, with target
position 1500.0, is started. Because of the response times (e.g., cycle time of user program, etc.), the axis comes
to a standstill briefly (see zoomed-in detail). When the axis reaches the new target position, this is signaled via
"Done_2".
An active MC_MoveAbsolute task is aborted by another MC_MoveAbsolute task. The abort is signaled via
"Abort_1". The axis is then moved at the new velocity to the new target position 1500.0. When the new target
position is reached, this is signaled via "Done_2".

Override response
The MC_MoveAbsolute task can be
aborted by the following motion control
tasks:







MC_Home Mode = 3
MC_Halt
MC_MoveAbsolute
MC_MoveRelative
MC_MoveVelocity
MC_MoveJog

The new MC_MoveAbsolute task aborts
the following active motion control tasks:







MC_Home Mode = 3
MC_Halt
MC_MoveAbsolute
MC_MoveRelative
MC_MoveVelocity
MC_MoveJog

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10.3 Basic motion control

10.3.2.6

MC_MoveRelative instruction

Table 10- 35 MC_MoveRelative instruction
LAD / FBD

Description
Use the MC_MoveRelative instruction to start a positioning motion relative to the start
position.
In order to use the MC_MoveRelative instruction, the axis must first be enabled.

STEP 7 automatically creates the DB when you insert the instruction.

Table 10- 36 Parameters for the MC_MoveRelative instruction
Parameter and type
Axis

Data type

Description

TO_Axis_1

Axis technology object

Execute

Bool

Start of the task with a positive edge (Default value: False)

Distance

Real

Travel distance for the positioning operation (Default value: 0.0)
Limit values: -1.0e12 ≤ Distance ≤ 1.0e12

Velocity

Real

Velocity of axis (Default value: 10.0)
This velocity is not always reached on account of the configured
acceleration and deceleration and the distance to be traveled.
Limit values: Start/stop velocity ≤ Velocity ≤ maximum velocity

Done

OUT

Bool

TRUE = Target position reached

Busy

OUT

Bool

TRUE = The task is being executed.

CommandAborted

OUT

Bool

TRUE = During execution the task was aborted by another task.

Error

OUT

Bool

TRUE = An error has occurred during execution of the task. The
cause of the error can be found in parameters "ErrorID" and
"ErrorInfo".

ErrorID

OUT

Word

Error ID for parameter "Error" (Default value: 0000)

ErrorInfo

OUT

Word

Error info ID for parameter "ErrorID" (Default value: 0000)

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10.3 Basic motion control

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The following values were configured in the "Dynamics > General" configuration window: Acceleration = 10.0 and
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①

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The axis is moved by an MC_MoveRelative task by the distance ("Distance") 1000.0. When the axis reaches the
target position, this is signaled via "Done_1". When "Done_1" = TRUE, another MC_MoveRelative task, with travel
distance 500.0, is started. Because of the response times (for example, cycle time of user program), the axis
comes to a standstill briefly (see zoomed-in detail). When the axis reaches the new target position, this is signaled
via "Done_2".
An active MC_MoveRelative task is aborted by another MC_MoveRelative task. The abort is signaled via
"Abort_1". The axis is then moved at the new velocity by the new distance ("Distance") 500.0. When the new target
position is reached, this is signaled via "Done_2".

Override response
The MC_MoveRelative task can be aborted
by the following motion control tasks:







MC_Home Mode = 3
MC_Halt
MC_MoveAbsolute
MC_MoveRelative
MC_MoveVelocity
MC_MoveJog

The new MC_MoveRelative task aborts the
following active motion control tasks:







MC_Home Mode = 3
MC_Halt
MC_MoveAbsolute
MC_MoveRelative
MC_MoveVelocity
MC_MoveJog

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10.3 Basic motion control

10.3.2.7

MC_MoveVelocity instruction

Table 10- 37 MC_MoveVelocity instruction
LAD / FBD

Description
Use the MC_MoveVelocity instruction to move the axis constantly at the specified
velocity.
In order to use the MC_MoveVelocity instruction, the axis must first be enabled.

STEP 7 automatically creates the DB when you insert the instruction.

Table 10- 38 Parameters for the MC_MoveVelocity instruction
Parameter and type

Data type

Description

Axis

TO_Axis_1

Axis technology object

Execute

Bool

Start of the task with a positive edge (Default value: False)

Velocity

Real

Velocity specification for axis motion (Default value: 10.0)
Limit values: Start/stop velocity ≤ |Velocity| ≤ maximum velocity
(Velocity = 0.0 is allowed)

Direction

Current

Int

Bool

Direction specification:


0: Direction of rotation corresponds to the sign of the value in
parameter "Velocity" (Default value)



1: Positive direction of rotation (The sign of the value in
parameter "Velocity" is ignored.)



2: Negative direction of rotation (The sign of the value in
parameter "Velocity" is ignored.)

Maintain current velocity:


FALSE: "Maintain current velocity" is deactivated. The values
of parameters "Velocity" and "Direction" are used. (Default
value)



TRUE: "Maintain current velocity" is activated. The values in
parameters "Velocity" and "Direction" are not taken into
account.
When the axis resumes motion at the current velocity, the
"InVelocity" parameter returns the value TRUE.

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Parameter and type
InVelocity

OUT

Busy

OUT

Data type

Description

Bool

TRUE:

Bool



If "Current" = FALSE: The velocity specified in parameter
"Velocity" was reached.



If "Current" = TRUE: The axis travels at the current velocity at
the start time.

TRUE = The task is being executed.

CommandAborted

OUT

Bool

TRUE = During execution the task was aborted by another task.

Error

OUT

Bool

TRUE = An error has occurred during execution of the task. The
cause of the error can be found in parameters "ErrorID" and
"ErrorInfo".

ErrorID

OUT

Word

Error ID for parameter "Error" (Default value: 0000)

ErrorInfo

OUT

Word

Error info ID for parameter "ErrorID" (Default value: 0000)

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The following values were configured in the "Dynamics > General" configuration window: Acceleration = 10.0 and
Deceleration = 10.0

①
②

An active MC_MoveVelocity task signals via "InVel_1" that its target velocity has been reached. It is then aborted
by another MC_MoveVelocity task. The abort is signaled via "Abort_1". When the new target velocity 15.0 is
reached, this is signaled via "InVel_2". The axis then continues moving at the new constant velocity.
An active MC_MoveVelocity task is aborted by another MC_MoveVelocity task prior to reaching its target velocity.
The abort is signaled via "Abort_1". When the new target velocity 15.0 is reached, this is signaled via "InVel_2".
The axis then continues moving at the new constant velocity.

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10.3 Basic motion control

Override response
The MC_MoveVelocity task can be aborted
by the following motion control tasks:







MC_Home Mode = 3
MC_Halt
MC_MoveAbsolute
MC_MoveRelative
MC_MoveVelocity
MC_MoveJog

The new MC_MoveVelocity task aborts the
following active motion control tasks:







MC_Home Mode = 3
MC_Halt
MC_MoveAbsolute
MC_MoveRelative
MC_MoveVelocity
MC_MoveJog

Note
Behavior with zero set velocity (Velocity = 0.0)
An MC_MoveVelocity task with "Velocity" = 0.0 (such as an MC_Halt task) aborts active
motion tasks and stops the axis with the configured deceleration. When the axis comes to a
standstill, output parameter "InVelocity" indicates TRUE for at least one program cycle.
"Busy" indicates the value TRUE during the deceleration operation and changes to FALSE
together with "InVelocity". If parameter "Execute" = TRUE is set, "InVelocity" and "Busy" are
latched.
When the MC_MoveVelocity task is started, status bit "SpeedCommand" is set in the
technology object. Status bit "ConstantVelocity" is set upon axis standstill. Both bits are
adapted to the new situation when a new motion task is started.

10.3.2.8

MC_MoveJog instruction

Table 10- 39 MC_MoveJog instruction
LAD / FBD

Description
Use the MC_MoveJog instruction to move the axis constantly at the specified velocity in
jog mode. This instruction is typically used for testing and commissioning purposes.
In order to use the MC_MoveJog instruction, the axis must first be enabled.

STEP 7 automatically creates the DB when you insert the instruction.

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10.3 Basic motion control
Table 10- 40 Parameters for the MC_MoveJog instruction
Parameter and type

Data type

Description

Axis

TO_Axis_1

Axis technology object

JogForward1

Bool

As long as the parameter is TRUE, the axis moves in the positive
direction at the velocity specified in parameter "Velocity". The sign of
the value in parameter "Velocity" is ignored. (Default value: False)

JogBackward1

Bool

As long as the parameter is TRUE, the axis moves in the negative
direction at the velocity specified in parameter "Velocity". The sign of
the value in parameter "Velocity" is ignored. (Default value: False)

Velocity

Real

Preset velocity for jog mode (Default value: 10.0)
Limit values: Start/stop velocity ≤ |Velocity| ≤ maximum velocity

InVelocity

OUT

Bool

TRUE = The velocity specified in parameter "Velocity" was reached.

Busy

OUT

Bool

TRUE = The task is being executed.

CommandAborted

OUT

Bool

TRUE = During execution the task was aborted by another task.

Error

OUT

Bool

TRUE = An error has occurred during execution of the task. The
cause of the error can be found in parameters "ErrorID" and
"ErrorInfo".

ErrorID

OUT

Word

Error ID for parameter "Error" (Default value: 0000)

ErrorInfo

OUT

Word

Error info ID for parameter "ErrorID" (Default value: 0000)

If both the JogForward and JogBackward parameters are simultaneously TRUE, the axis stops with the configured
deceleration. An error is indicated in parameters "Error", "ErrorID", and "ErrorInfo".

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The following values were configured in the "Dynamics > General" configuration window: Acceleration = 10.0 and
Deceleration = 5.0

①
②

The axis is moved in the positive direction in jog mode via "Jog_F". When the target velocity 50.0 is reached, this is
signaled via "InVelo_1". The axis brakes to a standstill again after Jog_F is reset.
The axis is moved in the negative direction in jog mode via "Jog_B". When the target velocity 50.0 is reached, this
is signaled via "InVelo_1". The axis brakes to a standstill again after Jog_B is reset.

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Override response
The MC_MoveJog task can be aborted by
the following motion control tasks:







MC_Home Mode = 3
MC_Halt
MC_MoveAbsolute
MC_MoveRelative
MC_MoveVelocity
MC_MoveJog

The new MC_MoveJog task aborts the
following active motion control tasks:
MC_Home Mode = 3
MC_Halt
MC_MoveAbsolute
MC_MoveRelative
MC_MoveVelocity
MC_MoveJog








10.3.3

Operation of motion control for S7-1200

10.3.3.1

CPU outputs used for motion control
The CPU provides one pulse output and one direction output for controlling a stepper motor
drive or a servo motor drive with pulse interface. The pulse output provides the drive with the
pulses required for motor motion. The direction output controls the travel direction of the
drive.
Pulse and direction outputs are permanently assigned to one another. Onboard CPU outputs
and outputs of a signal board can be used as pulse and direction outputs. You select
between onboard CPU outputs and outputs of the signal board during device configuration
under Pulse generators (PTO/PWM) on the "Properties" tab.

Table 10- 41 Address assignments of the pulse and direction outputs
CPU type

Outputs PTO2 1, 2

Outputs PTO1 1, 2

(CPU 1211C, CPU 212C, and CPU 1214C)

Pulse

Direction

Pulse

Direction

DC/DC/DC

Qx.0

Qx.1

Qx.2

Qx.3

Qx.0

Qx.1

Qx.2

Qx.3

Qy.0

Qy.1

Qx.0

Qx.1

Qx.2

Qx.3

Qy.0

Qy.1

Qy.2

Qy.3

Signal boards DI2/DO2

Qy.0

Qy.1

Signal boards DO4

Qy.0

Qy.1

Qy.2

Qy.3

Signal boards DI2/DO2

Qy.0

Qy.1

Signal boards DO4

Qy.0

Qy.1

Qy.2

Qy.3

Without signal board
Signal boards DI2/DO2
Signal boards DO4 4

AC/DC/RLY

DC/DC/RLY

Without signal board

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CPU type

Outputs PTO1 1, 2

(CPU 1211C, CPU 212C, and CPU 1214C)

Pulse

Outputs PTO2 1, 2

Direction

Pulse

Direction

x = Initial byte address of onboard CPU outputs (default value = 0)

y = Initial byte address of signal board outputs (default value = 4)

If a DC/DC/DC CPU variant is used together with a DI2/DO2 signal board, the signals of the PTO1 output can use either
the onboard CPU outputs (Qx.0 and Qx.1) or the outputs of the signal board (Qy.0 and Qy.1).

If a DC/DC/DC CPU variant is used together with a DO4 signal board, the signals of the PTO outputs can use either the
onboard CPU outputs (Qx.0 and Qx.1 for PTO1 and Qx.2 and Qx.3 for PTO2) or the outputs of the signal board (Qy.0
and Qy.1 for PTO1 and Qy.2 and Qy.3 for PTO2)

Drive interface
For motion control, you can optionally configure a drive interface for "Drive enabled" and
"Drive ready". When using the drive interface, the digital output for the drive enable and the
digital input for "drive ready" can be freely selected.
Note
The firmware will take control via the corresponding pulse and direction outputs if the PTO
(Pulse Train Output) has been selected and assigned to an axis.
With this takeover of the control function, the connection between the process image and I/O
output is also disconnected. While the user has the possibility of writing the process image of
pulse and direction outputs via the user program or watch table, this is never transferred to
the I/O output. Accordingly, it is also not possible to monitor the I/O output via the user
program or watch table. The information read merely reflects the value of the process image
and does not match the actual status of the I/O output in any respect.
For all other CPU outputs that are not used permanently by the CPU firmware, the status of
the I/O output can be controlled or monitored via the process image, as usual.

10.3.3.2

Hardware and software limit switches for motion control
Use the hardware and software limit switches to limit the "allowed travel range" and the
"working range" of your axis.
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Mechanical stop

Allowed travel range for the axis

Lower and upper hardware limits

Working range of the axis

Lower and upper software limits

Distance

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Hardware and software limit switches must be activated prior to use in the configuration or in
the user program. Software limit switches are only active after homing the axis.

Hardware limit switches
Hardware limit switches determine the maximum travel range of the axis. Hardware limit
switches are physical switching elements that must be connected to interrupt-capable inputs
of the CPU. Use only hardware limit switches that remain permanently switched after being
approached. This switching status may only be revoked after a return to the allowed travel
range.
When the hardware limit switches are approached, the axis brakes to a standstill at the
configured emergency deceleration. The specified emergency deceleration must be
sufficient to reliably stop the axis before the mechanical stop. The following diagram
presents the behavior of the axis after it approaches the hardware limit switches.

(

)

①
②

The axis brakes to a standstill at the configured emergency decleration.

[Velocity]

Allowed travel range

Distance

Range in which the hardware limit switches signal the stats "approached".

Mechanical stop

Lower hardware limit switch

Upper hardware limit switch

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Software limit switches
Software limit switches limit the "working range" of the axis. They should fall inside the
hardware limit switches relative to the travel range. Because the positions of the software
limit switches can be set flexibly, the working range of the axis can be restricted on an
individual basis depending on the current traversing profile. In contrast to hardware limit
switches, software limit switches are implemented exclusively by means of the software and
do not require their own switching elements.
If software limit switches are activated, an active motion is stopped at the position of the
software limit switch. The axis is braked at the configured deceleration. The following
diagram presents the behavior of the axis until it reaches the software limit switches.
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The axis brakes to a standstill at the configured deceleration.

[Velocity]

Working range

Distance

Lower software limit switch

Upper software limit switch

Use additional hardware limit switches if a mechanical endstop is located after the software
limit switches and there is a risk of mechanical damage.

Additional information
Your user program can override the hardware or software position limits by enabling or
disabling both hardware and software limits functionality. The selection is made from the
Axis DB.
● To enable or disable the hardware limit functionality, access the "Active" tag (Bool) in the
DB path "/Config/PositonLimits_HW". The state of the "Active" tag enables
or disables the use of hardware position limits.
● To enable or disable software position limit functionality, access "Active" tag (Bool) in the
DB path "/Config/Position Limits_SW". The state of this "Active" tag enables
or disables the software position limits.

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You can also modify the software position limits with your user program (for example, to add
flexibility for machine setup or to shorten machine change-over time). Your user program can
write new values to the " MinPosition " and " MaxPosition " tags (engineering units in Real
format) in the DB "/Config/PositionLimits_SW".

10.3.3.3

Homing
Homing refers to the matching of the axis coordinates to the real, physical drive position. (If
the drive is currently at position x, the axis will be adjusted to be in position x.) For positioncontrolled axes, the entries and displays for the position refer exactly to these axis
coordinates.
Note
The agreement between the axis coordinates and the real situation is extremely important.
This step is necessary to ensure that the absolute target position of the axis is also achieved
exactly with the drive.
The MC_Home instruction initiates the homing of the axis.
There are 4 different homing functions. The first two functions allow the user to set the
current position of the axis and the second two position the axis with respect to a Home
reference Sensor.
● Mode 0 - Direct Referencing Absolute: When executed this mode tells the axis exactly
where it is. It sets the internal position variable to the value of the Position input of the
Homing instruction. This is used for machine calibration and setup.
The axis position is set regardless of the reference point switch. Active traversing motions
are not aborted. The value of the Position input parameter of the MC_Home instruction is
set immediately as the reference point of the axis. To assign the reference point to an
exact mechanical position, the axis must be at a standstill at this position at the time of
the homing operation.
● Mode 1 - Direct Referencing Relative: When executed this mode uses the internal
position variable and adds the value of the Position input on the Homing instruction to it.
This is typically used to account for machine offset.
The axis position is set regardless of the reference point switch. Active traversing motions
are not aborted. The following statement applies to the axis position after homing: New
axis position = current axis position + value of the Position parameter of the MC_Home
instruction.
● Mode 2 - Passive Referencing: When the axis is moving and passes the Reference Point
Switch the current position is set as the home position. This feature will help account for
normal machine wear and gear backlash and prevent the need for manual compensation
for wear. The Position input on the Homing instruction, as before, adds to the location
indicated by the Reference Point Switch allowing easy offset of the Home position.
During passive homing, the MC_Home instruction does not carry out any homing motion.
The traversing motion required for this step must be implemented by the user via other
motion control instructions. When the reference point switch is detected, the axis is
homed according to the configuration. Active traversing motions are not aborted upon
start of passive homing.

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● Mode 3 - Active Referencing: This mode is the most precise method of Homing the Axis.
The initial direction and velocity of movement is configured in the Technology Object
Configuration Extended Parameters-Homing. This is dependent upon machine
configuration. There is also the ability to determine if the leading edge or falling edge of
the Reference Point Switch signal is the Home position. Virtually all sensors have an
active range and if the Steady State On position was used as the Home signal then there
would be a possibility for error in the Homing position since the On signal active range
would cover a range of distance. By using either the leading or falling edge of that signal
a much more precise Home position results. As with all other modes the value of the
Position input on the Homing instruction is added to the Hardware referenced position.
In active homing mode, the MC_Home instruction performs the required reference point
approach. When the reference point switch is detected, the axis is homed according to
the configuration. Active traversing motions are aborted.
Modes 0 and 1 do not require that the axis be moved at all. They are typically used in setup
and calibration. Modes 2 and 3 require that the axis move and pass a sensor that is
configured in the "Axis" technology object as the Reference Point Switch. The reference
point which can be placed in the work area of the axis or outside of the normal work area but
within movement range.

Configuration of homing parameters
Configure the parameters for active and passive homing in the "Homing" configuration
window. The homing method is set using the "Mode" input parameter of the motion control
instruction. Here, Mode = 2 means passive homing and Mode = 3 means active homing.
NOTICE
Use one of the following measures to ensure that the machine does not travel to a
mechanical endstop in the event of a direction reversal:
 Keep the approach velocity low
 Increase the configured acceleration/deceleration
 Increase the distance between hardware limit switch and mechanical stop

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Table 10- 42 Configuration parameters for homing the axis
Parameter

Description

Input reference point switch

Select the digital input for the reference point switch from the drop-down list box. The
input must be interrupt-capable. The onboard CPU inputs and inputs of an inserted
signal board can be selected as inputs for the reference point switch.

(Active and passive homing)

The default filter time for the digital inputs is 6.4 ms. When the digital inputs are used
as a reference point switch, this can result in undesired decelerations and thus
inaccuracies. Depending on the reduced velocity and extent of the reference point
switch, the reference point may not be detected. The filter time can be set under
"Input filter" in the device configuration of the digital inputs.
The specified filter time must be less than the duration of the input signal at the
reference point switch.
Auto reverse after reaching the
hardware limit switches
(Active homing only)

Activate the check box to use the hardware limit switch as a reversing cam for the
reference point approach. The hardware limit switches must be configured and
activated for direction reversal.
If the hardware limit switch is reached during active homing, the axis brakes at the
configured deceleration (not with the emergency deceleration) and reverses direction.
The reference point switch is then sensed in reverse direction.
If the direction reversal is not active and the axis reaches the hardware limit switch
during active homing, the reference point approach is aborted with an error and the
axis is braked at the emergency deceleration.

Approach direction
(Active and passive homing)

Reference point switch

With the direction selection, you determine the "approach direction" used during
active homing to search for the reference point switch, as well as the homing
direction. The homing direction specifies the travel direction the axis uses to
approach the configured side of the reference point switch to carry out the homing
operation.


Active homing: Select whether the axis is to be referenced on the left or right side
of the reference point switch. Depending on the start position of the axis and the
configuration of the homing parameters, the reference point approach sequence
can differ from the diagram in the configuration window.



Passive homing: With passive homing, the traversing motions for purposes of
homing must be implemented by the user via motion commands. The side of the
reference point switch on which homing occurs depends on the following factors:

(Active and passive homing)

Approach velocity
(Active homing only)

Reduced velocity
(Active homing only)

–

"Approach direction" configuration

–

"Reference point switch" configuration

–

Current travel direction during passive homing

Specify the velocity at which the reference point switch is to be searched for during
the reference point approach.
Limit values (independent of the selected user unit):
Start/stop velocity ≤ approach velocity ≤ maximum velocity
Specify the velocity at which the axis approaches the reference point switch for
homing.
Limit values (independent of the selected user unit):
Start/stop velocity ≤ reduced velocity ≤ maximum velocity

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Parameter

Description

Home position offset

If the desired reference position deviates from the position of the reference point
switch, the home position offset can be specified in this field.

(Active homing only)

If the value does not equal 0, the axis executes the following actions following
homing at the reference point switch:
1. Move the axis at reduced velocity by the value of the home position offset.
2. When the position of the home position offset is reached, the axis position is set
to the absolute reference position. The absolute reference position is specified via
parameter "Position" of motion control instruction "MC_Home".
Limit values (independent of the selected user unit):
-1.0e12 ≤ home position offset ≤ 1.0e12

Table 10- 43 Factors that affect homing
Influencing factors:
Configuration

Configuration

Approach direction

Reference point switch

Positive

"Left (negative) side"

Positive

"Right (positive) side"

Negative

"Left (negative) side"

Negative

"Right (positive) side"

Result:
Current travel direction

Homing on
Reference point switch

Positive direction

Left

Negative direction

Right

Positive direction

Right

Negative direction

Left

Positive direction

Right

Negative direction

Left

Positive direction

Left

Negative direction

Right

Sequence for active homing
You start active homing with motion control instruction "MC_Home" (input parameter
Mode = 3). Input parameter "Position" specifies the absolute reference point coordinates in
this case. Alternatively, you can start active homing on the control panel for test purposes.
The following diagram shows an example of a characteristic curve for an active reference
point approach with the following configuration parameters:
● "Approach direction" = "Positive approach direction"
● "Reference point switch" = "Right (positive) side"
● Value of "home position offset" > 0

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Table 10- 44 Velocity characteristics of MC homing
Operation

Notes

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Approach velocity

Reduced velocity

Home position coordinate

Home position offset

①

Search phase (blue curve segment): When active homing starts, the axis accelerates to the configured "approach
velocity" and searches at this velocity for the reference point switch.

②

Reference point approach (red curve section): When the reference point switch is detected, the axis in this example
brakes and reverses, to be homed on the configured side of the reference point switch at the configured "reduced
velocity".

③

Travel to reference point position (green curve segment): After homing at the reference point switch, the axis travels
to the "Reference point coordinates" at the "reduced velocity". On reaching the "Reference point coordinates", the
axis is stopped at the position value that was specified in the Position input parameter of the MC_Home instruction".

Note
If the homing search does not function as you expected, check the inputs assigned to the
hardware limits or to the reference point. These inputs may have had their edge interrupts
disabled in device configuration.
Examine the configuration data for the axis technology object of concern to see which inputs
(if any) are assigned for "HW Low Limit Switch Input", "HW High Limit Switch Input", and
"Input reference point switch". Then open the Device configuration for the CPU and examine
each of the assigned inputs. Verify the "Enable rising edge detection" and "Enable falling
edge detection" are both selected. If these properties are not selected, delete the specified
inputs in the axis configuration and select them again.

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10.3.3.4

Jerk limit
With the jerk limit you can reduce the stresses on your mechanics during an acceleration
and deceleration ramp. The value for the acceleration and deceleration is not changed
abruptly when the step limiter is active; it is adapted in a transition phase. The figure below
shows the velocity and acceleration curve without and with jerk limit.

Table 10- 45 Jerk limit
Travel without step limiter

Travel with step limiter

The jerk limit gives a "smoothed" velocity profile of the axis motion. This ensures soft starting
and braking of a conveyor belt for example.

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10.3.4

Commissioning

"Status and error bits" diagnostic function
Use the "Status and error bits" diagnostic function to monitor the most important status and
error messages for the axis. The diagnostic function display is available in online mode in
"Manual control" mode and in "Automatic control" when the axis is active.
Table 10- 46 Status of the axis
Status
Enabled

Description
The axis is enabled and ready to be controlled via motion control tasks.
(Tag of technology object: .StatusBits.Enable)

Homed

The axis is homed and is capable of executing absolute positioning tasks of motion control
instruction "MC_MoveAbsolute". The axis does not have to be homed for relative homing. Special
situations:


During active homing, the status is FALSE.

 If a homed axis undergoes passive homing, the status is set to TRUE during passive homing.
(Tag of technology object: .StatusBits.HomingDone)
Error

An error has occurred in the "Axis" technology object. More information about the error is available
in automatic control at the ErrorID and ErrorInfo parameters of the motion control instructions. In
manual mode, the "Last error" field of the control panel displays detailed information about the
cause of error.

Control panel active

The "Manual control" mode was enabled in the control panel. The control panel has control priority
over the "Axis" technology object. The axis cannot be controlled from the user program.

(Tag of technology object: .StatusBits.Error)

(Tag of technology object: .StatusBits.ControlPanelActive)

Table 10- 47 Drive status
Status

Description

Drive ready

The drive is ready for operation.

Error

The drive has reported an error after failure of its ready signal.

(Tag of technology object: .StatusBits.DriveReady)
(Tag of technology object: .ErrorBits.DriveFault)

Table 10- 48 Status of the axis motion
Status
Standstill

Description
The axis is at a standstill.
(Tag of technology object: .StatusBits.StandStill)

Accelerating

The axis accelerates.
(Tag of technology object: .StatusBits.Acceleration)

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Status

Description

Constant velocity

The axis travels at constant velocity.
(Tag of technology object: .StatusBits.ConstantVelocity)

Decelerating

The axis decelerates (slows down).
(Tag of technology object: .StatusBits.Deceleration)

Table 10- 49 Status of the motion mode
Status

Description

Positioning

The axis executes a positioning task of motion control instruction "MC_MoveAbsolute" or
"MC_MoveRelative" or of the control panel.
(Tag of technology object: .StatusBits.PositioningCommand)

Speed Command

The axis executes a task at set speed of motion control instruction "MC_MoveVelocity" or
"MC_MoveJog" or of the control panel.
(Tag of technology object: .StatusBits.SpeedCommand)

Homing

The axis executes a homing task of motion control instruction "MC_Home" or the control
panel.
(Tag of technology object: .StatusBits.Homing)

Table 10- 50 Error bits
Error

Description

Min software limit reached

The lower software limit switch has been reached.
(Tag of technology object: .ErrorBits.SwLimitMinReached)

Min software limit exceeded

The lower software limit switch has been exceeded.
(Tag of technology object: .ErrorBits.SwLimitMinExceeded)

Max software limit reached

The upper software limit switch has been reached.
(Tag of technology object: .ErrorBits.SwLimitMaxReached)

Max software limit exceeded

The upper software limit switch has been exceeded.
(Tag of technology object: .ErrorBits.SwLimitMaxExceeded)

Negative hardware limit

The lower hardware limit switch has been approached.

Positive hardware limit

The upper hardware limit switch has been approached.

PTO and HSC already used

A second axis is using the same PTO and HSC and is enabled with "MC_Power".

(Tag of technology object: .ErrorBits.HwLimitMin)
(Tag of technology object: .ErrorBits.HwLimitMax)
(Tag of technology object: .ErrorBits.HwUsed)
Configuration error

The "Axis" technology object was incorrectly configured or editable configuration data
were modified incorrectly during runtime of the user program.
(Tag of technology object: .ErrorBits.ConfigFault)

General Error

An internal error has occurred.
(Tag of technology object: .ErrorBits.SystemFault)

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"Motion status" diagnostic function
Use the "Motion status" diagnostic function to monitor the motion status of the axis. The
diagnostic function display is available in online mode in "Manual control" mode and in
"Automatic control" when the axis is active.
Table 10- 51 Motion status
Status

Description

Target position

The "Target position" field indicates the current target position of an active positioning task of
motion control instruction "MC_MoveAbsolute" or "MC_MoveRelative" or of the control panel.
The value of the "Target position" is only valid during execution of a positioning task.
(Tag of technology object: .MotionStatus.TargetPosition)

Current position

The "Current position" field indicates the current axis position. If the axis is not homed, the
value indicates the position value relative to the enable position of the axis.

Current velocity

The "Current velocity" field indicates the actual axis velocity.

(Tag of technology object: .MotionStatus.Position)
(Tag of technology object: .MotionStatus.Velocity)

Table 10- 52 Dynamic limits
Dynamic limit
Velocity

Description
The "Velocity" field indicates the configured maximum velocity of the axis.
(Tag of technology object: .Config.DynamicLimits.MaxVelocity)

Acceleration

The "Acceleration" field indicates the currently configured acceleration of the axis.
(Tag of technology object: .Config.DynamicDefaults.Acceleration)

Deceleration

The "Deceleration" field indicates the currently configured deceleration of the axis.
(Tag of technology object: .Config.DynamicDefaults.Deceleration)

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10.3.5

Monitoring active commands

10.3.5.1

Monitoring MC instructions with a "Done" output parameter
Motion control instructions with the output parameter "Done" are started by the input
parameter "Execute" and have a defined conclusion (for example, with motion control
instruction "MC_Home": Homing was successful). The task is complete and the axis is at a
standstill.
● The output parameter "Done" indicates the value TRUE, if the task has been successfully
completed.
● The output parameters "Busy", "CommandAborted", and "Error" signal that the task is still
being processed, has been aborted or an error is pending. The motion control instruction
"MC_Reset" cannot be aborted and thus has no "CommandAborted" output parameter.
– During processing of the motion control task, the output parameter "Busy" indicates
the value TRUE. If the task has been completed, aborted, or stopped by an error, the
output parameter "Busy" changes its value to FALSE. This change occurs regardless
of the signal at input parameter "Execute".
– Output parameters "Done", "CommandAborted", and "Error" indicate the value TRUE
for at least one cycle. These status messages are latched while input parameter
"Execute" is set to TRUE.
The tasks of the following motion control instructions have a defined conclusion:
● MC_Reset
● MC_Home
● MC_Halt
● MC_MoveAbsolute
● MC_MoveRelative
The behavior of the status bits is presented below for various example situations.
● The first example shows the behavior of the axis for a completed task. If the motion
control task has been completely executed by the time of its conclusion, this is indicated
by the value TRUE in output parameter "Done". The signal status of input parameter
"Execute" influences the display duration in the output parameter "Done".
● The second example shows the behavior of the axis for an aborted task. If the motion
control task is aborted during execution, this is indicated by the value TRUE in output
parameter "CommandAborted". The signal status of the input parameter "Execute"
influences the display duration in the output parameter "CommandAborted".
● The third example shows the behavior of the axis if an error occurs. If an error occurs
during execution of the motion control task, this is indicated by the value TRUE in the
output parameter "Error". The signal status of the input parameter "Execute" influences
the display duration in the output parameter "Error".

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Table 10- 53 Example 1 - Complete execution of task

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If "Execute" = FALSE during the processing of the task

If "Execute" = FALSE after completion of the task

① The task is started with a positive edge at the input parameter "Execute". Depending on the programming, "Execute"

can still be reset to the value FALSE during the task, or the value TRUE can be retained until after completion of the task.

② While the task is active, the output parameter "Busy" indicates the value TRUE.
③ With conclusion of the task (for example, for motion control instruction "MC_Home": Homing was successful), output

parameter "Busy" changes to FALSE and "Done" to TRUE.

④ If "Execute" retains the value TRUE until after completion of the task, then "Done" also remains TRUE and changes its
value to FALSE together with "Execute".
⑤ If "Execute" has been set to FALSE before the task is complete, "Done" indicates the value TRUE for only one
execution cycle.

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Table 10- 54 Example 2 - Aborting the task
Abort

Abort

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If "Execute" = FALSE before the task is aborted

If "Execute" = FALSE after the task is aborted

① The task is started with a positive edge at the input parameter "Execute". Depending on the programming, "Execute"

can still be reset to the value FALSE during the task, or the value TRUE can be retained until after completion of the task.

② While the task is active, the output parameter "Busy" indicates the value TRUE.
③ During task execution, the task is aborted by another motion control task. If the task is aborted, output parameter
"Busy" changes to FALSE and "CommandAborted" to TRUE.

④ If "Execute" retains the value TRUE until after the task is aborted, then "CommandAborted" also remains TRUE and
changes its value to FALSE together with "Execute".
⑤ If "Execute" has been set to FALSE before the task is aborted, "CommandAborted" indicates the value TRUE for only
one execution cycle.

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10.3 Basic motion control
Table 10- 55 Example 3 - Error during task execution
Error

Error

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If "Execute" = FALSE before the error occurs

If "Execute" = FALSE after the error occurs

① The task is started with a positive edge at the input parameter "Execute". Depending on the programming, "Execute"

can still be reset to the value FALSE during the task, or the value TRUE can be retained until after completion of the task.

② While the task is active, the output parameter "Busy" indicates the value TRUE.
③ An error occurred during task execution. When the error occurs, the output parameter "Busy" changes to FALSE and

"Error" to TRUE.

④ If "Execute" retains the value TRUE until after the error occurs, then "Error" also remains TRUE and only changes its
value to FALSE together with "Execute".
⑤ If "Execute" has been set to FALSE before the error occurs, "Error" indicates the value TRUE for only one execution
cycle.

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10.3.5.2

Monitoring the MC_Velocity instruction
The tasks of motion control instruction "MC_MoveVelocity" constantly at the specified
velocity.
● The tasks of motion control instruction "MC_MoveVelocity" do not have a defined end.
The task objective is fulfilled when the parameterized velocity is reached for the first time
and the axis travels at constant velocity. When the parameterized velocity is reached, this
is indicated by the value TRUE in output parameter "InVelocity".
● The task is complete when the parameterized velocity has been reached and input
parameter "Execute" has been set to the value FALSE. However, the axis motion is not
yet complete upon completion of the task. For example, the axis motion can be stopped
with motion control task "MC_Halt".
● The output parameters "Busy", "CommandAborted", and "Error" signal that the task is still
being processed, has been aborted or an error is pending.
– During execution of the motion control task, output parameter "Busy" indicates the
value TRUE. If the task has been completed, aborted, or stopped by an error, the
output parameter "Busy" changes its value to FALSE. This change occurs regardless
of the signal at input parameter "Execute".
– The output parameters "InVelocity", "CommandAborted", and "Error" indicate the
value TRUE for at least one cycle, when their conditions are met. These status
messages are latched while input parameter "Execute" is set to TRUE.
The behavior of the status bits is presented below for various example situations.
● The first example shows the behavior when the axis reaches the parameterized velocity.
If the motion control task has been executed by the time the parameterized velocity is
reached, this is indicated by the value TRUE in output parameter "InVelocity". The signal
status of the input parameter "Execute" influences the display duration in the output
parameter "InVelocity".
● The second example shows the behavior if the task is aborted before achieving the
parameterized velocity. If the motion control task is aborted before the parameterized
velocity is reached, this is indicated by the value TRUE in output parameter
"CommandAborted". The signal status of input parameter "Execute" influences the
display duration in output parameter "CommandAborted".
● The third example shows the behavior of the axis if an error occurs before achieving the
parameterized velocity. If an error occurs during execution of the motion control task
before the parameterized velocity has been reached, this is indicated by the value TRUE
in the output parameter "Error". The signal status of the input parameter "Execute"
influences the display duration in the output parameter "Error".

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Technology instructions
10.3 Basic motion control
Table 10- 56 Example 1 - If the parameterized velocity is reached

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If "Execute" = FALSE before the configured velocity is
reached

If "Execute" = FALSE after the configured velocity is
reached

① The task is started with a positive edge at the input parameter "Execute". Depending on the programming, "Execute"

can be reset to the value FALSE event before the parameterized velocity is reached, or alternatively only after it has been
reached.

② While the task is active, the output parameter "Busy" indicates the value TRUE.
③ When the parameterized velocity is reached, the output parameter "InVelocity" changes to TRUE.
④ If "Execute" retains the value TRUE even after the parameterized velocity has been reached, the task remains active.

"InVelocity" and "Busy" retain the value TRUE and only change their status to FALSE together with "Execute".

⑤ If "Execute" has been reset to FALSE before the parameterized velocity is reached, the task is complete when the
parameterized velocity is reached. "InVelocity" indicates the value TRUE for one execution cycle and changes to FALSE
together with "Busy".

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10.3 Basic motion control
Table 10- 57 Example 2 - If the task is aborted prior to reaching the parameterized velocity
Abort

Abort

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If "Execute" = FALSE before the task is aborted

If "Execute" = FALSE after the task is aborted

① The task is started with a positive edge at the input parameter "Execute". Depending on the programming, "Execute"
can still be reset to the value FALSE during the task, or the value TRUE can be retained until after the task is aborted.

④ If "Execute" retains the value TRUE until after the task is aborted, then "CommandAborted" also remains TRUE and
changes its status to FALSE together with "Execute".
⑤ If "Execute" has been reset to FALSE before the task is aborted, "CommandAborted" indicates the value TRUE for only
one execution cycle.

Note
Under the following conditions, an abort is not indicated in output parameter
"CommandAborted":
 The parameterized velocity has been reached, input parameter "Execute" has the value
FALSE, and a new motion control task is initiated.
 When the parameterized velocity is reached and input parameter "Execute" has the value
FALSE, the task is complete. Therefore, the start of a new task is not indicated as an
abort.

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Technology instructions
10.3 Basic motion control
Table 10- 58 Example 3 - If an error occurs prior to reaching the parameterized velocity
Error

Error

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If "Execute" = FALSE before the error occurs

If "Execute" = FALSE after the error occurs

① The task is started with a positive edge at the input parameter "Execute". Depending on the programming, "Execute"

can still be reset to the value FALSE during the task, or the value TRUE can be retained until after the error has occurred.

"Error" to TRUE.

④ If "Execute" retains the value TRUE until after the error has occurred, then "Error" also remains TRUE and only
changes its status to FALSE together with "Execute".
⑤ If "Execute" has been reset to FALSE before the error occurs, "Error" indicates the value TRUE for only one execution
cycle.
Note
Under the following conditions, an error is not indicated in output parameter "Error":
 The parameterized velocity has been reached, input parameter "Execute" has the value
FALSE, and an axis error occurs (software limit switch is approached, for example).
 When the parameterized velocity is reached and input parameter "Execute" has the value
FALSE, the task is complete. After completion of the task, the axis error is only indicated
in the motion control instruction "MC_Power".

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10.3.5.3

Monitoring the MC_MoveJog instruction
The tasks of motion control instruction "MC_MoveJog" implement a jog operation.
● The motion control tasks "MC_MoveJog" do not have a defined end. The task objective is
fulfilled when the parameterized velocity is reached for the first time and the axis travels
at constant velocity. When the parameterized velocity is reached, this is indicated by the
value TRUE in output parameter "InVelocity".
● The order is complete when input parameter "JogForward" or "JogBackward" has been
set to the value FALSE and the axis has come to a standstill.
● The output parameters "Busy", "CommandAborted", and "Error" signal that the task is still
being processed, has been aborted or an error is pending.
– During processing of the motion control task, the output parameter "Busy" indicates
the value TRUE. If the task has been completed, aborted, or stopped by an error, the
output parameter "Busy" changes its value to FALSE.
– The output parameter "InVelocity" indicates the status TRUE, as long as the axis is
moving at the parameterized velocity. The output parameters "CommandAborted" and
"Error" indicate the status for at least one cycle. These status messages are latched
as long as either input parameter "JogForward" or "JogBackward" is set to TRUE.
The behavior of the status bits is presented below for various example situations.
● The first example shows the behavior or the axis if the parameterized velocity is reached
and maintained. If the motion control task has been executed by the time the
parameterized velocity is reached, this is indicated by the value TRUE in output
parameter "InVelocity".
● The second example shows the behavior of the axis if the task is aborted. If the motion
control task is aborted during execution, this is indicated by the value TRUE in output
parameter "CommandAborted". The behavior is independent of whether or not the
parameterized velocity has been reached.
● The third example shows the behavior of the axis if an error occurs. If an error occurs
during execution of the motion control task, this is indicated by the value TRUE in output
parameter "Error". The behavior is independent of whether or not the parameterized
velocity has been reached.

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Technology instructions
10.3 Basic motion control
Table 10- 59 Example 1 - If the parameterized velocity is reached and maintained

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JogForward

JogBackward

① The task is started with a positive edge at the input parameter "JogForward" or "JogBackward".
② While the task is active, the output parameter "Busy" indicates the value TRUE.
③ When the parameterized velocity is reached, the output parameter "InVelocity" changes to TRUE.
④ When the input parameter "JogForward" or "JogBackward" is reset to the value FALSE, the axis motion ends. The axis

starts to decelerate. As a result, the axis no longer moves at constant velocity and the output parameter "InVelocity"
changes its status to FALSE.

⑤ If the axis has come to a standstill, the motion control task is complete and the output parameter "Busy" changes its
value to FALSE.

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Table 10- 60 Example 2 - If the task is aborted during execution
Abort

Abort

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JogForward

JogBackward

① The task is started with a positive edge at the input parameter "JogForward" or "JogBackward".
② While the task is active, the output parameter "Busy" indicates the value TRUE.
③ During task execution, the task is aborted by another motion control task. If the task is aborted, output parameter
"Busy" changes to FALSE and "CommandAborted" to TRUE.

④ When the input parameter "JogForward" or "JogBackward" is reset to the value FALSE, the output parameter
"CommandAborted" changes its value to FALSE.

Note
The task abort is indicated in the output parameter "CommandAborted" for only one
execution cycle, if all conditions below are met:
The input parameters "JogForward" and "JogBackward" have the value FALSE (but the axis
is still decelerating) and a new motion control task is initiated.

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Technology instructions
10.3 Basic motion control
Table 10- 61 Example 3 - If an error has occurred during task execution
Error

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JogBackward

JogForward

① The task is started with a positive edge at the input parameter "JogForward" or "JogBackward".
② While the task is active, the output parameter "Busy" indicates the value TRUE.
③ An error occurred during task execution. When the error occurs, the output parameter "Busy" changes to FALSE and

"Error" to TRUE.

④ When the input parameter "JogForward" or "JogBackward" is reset to the value FALSE, the output parameter "Error"
changes its value to FALSE.
Note
An error occurrence is indicated in the output parameter "Error" for only one execution cycle,
if all the conditions below are met:
The input parameters "JogForward" and "JogBackward" have the value FALSE (but the axis
is still decelerating) and a new error occurs (software limit switch is approached, for
example).

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PROFINET and PROFIBUS

The S7-1200 offers several types of communication between CPUs and programming
devices, HMIs, and other CPUs:
● PROFINET (for exchanging data through the user program with other communications
partners via Ethernet):
– For PROFINET and PROFIBUS, the CPU supports a total of 16 devices and 256
submodules, with a maximum of 8 PROFINET IO devices and 128 submodules,
whichever is reached first.
– S7 communication
– User Datagram Protocol (UDP) protocol
– ISO on TCP (RFC 1006)
– Transport Control Protocol (TCP)
As an IO controller using PROFINET RT, the S7-1200 communicates with up to 8 PN
devices on the local PN network or through a PN/PN coupler (link). In addition, it supports a
PN/DP coupler for connection to a PROFIBUS network. Refer to PROFIBUS and PROFINET
International, PI (www.us.profinet.com) for more information.
● PROFIBUS:
– CM 1242-5: Operates as DP slave
– CM 1243-5: Operates as DP master class1
– For PROFINET and PROFIBUS, the CPU supports a total of 16 devices and 256
submodules, with a maximum of 16 PROFIBUS DP slave devices and 256
submodules (if no PROFINET IO devices or submodules are configured).
Note
The 16 devices include the following:
 The DP slave modules attached by the DP master (CM 1243-5)
 Any DP slave module (CM 1242-5) connected to the CPU
 Any PROFINET device connected to the CPU over the PROFINET port
For example, a configuration with three PROFIBUS CMs (one CM 1243-5 master and
two CM 1242-5 slave modules) would reduce the maximum number of slave modules
that can be accessed by the DP Master (CM 1243-5) to 14.
● S7 CPU to S7 CPU communication
● Teleservice communication

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11.1 Number of asynchronous communication connections supported

11.1

Number of asynchronous communication connections supported
The CPU supports the following maximum number of simultaneous, asynchronous
communication connections:
● 4 connections for HMI to CPU communication: This supports 2 HMI devices with up to 2
connections per HMI device.
● 3 connections are reserved for programming device (PG) to CPU communication: A
single PG might use all 3 connections.
● 11 connections for program communication using the communication instructions (GET
and PUT): The CPU supports 3 connections for receiving GET/PUT data and 8
connections for sending GET/PUT data.
– The active S7 CPU uses GET and PUT instructions (S7-300 and S7-400) or
ETHx_XFER instructions (S7-200).
● 8 connections for Open User Communications (active or passive): TSEND_C, TRCV_C,
TCON, TDISCON, TSEND, and TRCV.

11.2

PROFINET

11.2.1

Local/Partner connection
A Local (active) / Partner (passive) connection defines a logical assignment of two
communication partners to establish communication services. A connection defines the
following:
● Communication partners involved
● Type of connection (for example, a PLC, HMI, or device connection)
● Connection path
Communication partners execute the instructions to set up and establish the communication
connection. You use parameters to specify the active and passive communication end point
partners. After the connection is set up and established, it is automatically maintained and
monitored by the CPU. Refer to the section on "Configuring the Local/Partner connection"
(Page 110) for information about configuring the parameters for the connection.
If the connection is terminated (for example, due to a line break or due to the remote
communications partner), the active partner attempts to re-establish the configured
connection. You do not have to execute the communication instruction again.

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PROFINET and PROFIBUS
11.2 PROFINET
The CPU can communicate with other CPUs, with programming devices, with HMI devices,
and with non-Siemens devices using standard TCP communications protocols.
Programming device connected to the
CPU

HMI connected to the CPU

A CPU connected to another CPU

The PROFINET port on the CPU does not contain an Ethernet switching device. A direct
connection between a programming device or HMI and a CPU does not require an Ethernet
switch. However, a network with more than two CPUs or HMI devices requires an Ethernet
switch.

① CSM1277

Ethernet switch

You can use the rack-mounted CSM1277 4-port Ethernet switch for connecting multiple
CPUs and HMI devices.

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11.2 PROFINET

11.2.2

Connections and port IDs for the PROFINET instructions
When you insert the TSEND_C, TRCV_C or TCON PROFINET instructions into your user
program, STEP 7 creates an instance DB to configure the communications channel (or
connection) between the devices (Page 110). Use the "Properties" of the instruction to
configure the parameters for the connection. Among the parameters is the port ID for that
connection.
● The connection ID must be unique for the CPU. Each connection that you create must
have a different DB and port ID.
● Both the local CPU and the partner CPU can use the same port ID number for the same
connection, but the port ID numbers are not required to match. The port ID number is
relevant only for the PROFINET instructions within the user program of the individual
CPU.
● You can use any number for the port ID of the CPU. However, configuring the port IDs
sequentially from "1" provides an easy method for tracking the number of connections in
use for a specific CPU.
Note
Each TSEND_C, TRCV_C or TCON instruction in your user program creates a new
connection. It is important to use the correct port ID for each connection.
The following example shows the communication between two CPUs that utilize 2 separate
connections for sending and receiving the data.
● The TSEND_C instruction in CPU_1 links to the TRCV_V in CPU_2 over the first
connection ("port ID 1" on both CPU_1 and CPU_2).
● The TRCV_C instruction in CPU_1 links to the TSEND_C in CPU_2 over the second
connection ("port ID 2" on both CPU_1 and CPU_2).

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① TSEND_C on CPU_1 creates a

connection and assigns a port ID to
that connection (port ID 1 for CPU_1).

② TRCV_C on CPU_2 creates the

connection for CPU_2 and assigns the
port ID (port ID 1 for CPU_2).

③ TRCV_C on CPU_1 creates a second

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connection for CPU_1 and assigns a
different port ID for that connection
(port ID 2 for CPU_1).

④ TSEND_C on CPU_2 creates a

second connection and assigns a
different port ID for that connection
(port ID 2 for CPU_2).

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PROFINET and PROFIBUS
11.2 PROFINET
The following example shows the communication between two CPUs that utilize 1
connection for both sending and receiving the data.
● Each CPU uses a TCON instruction to configure the connection between the two CPUs.
● The TSEND instruction in CPU_1 links to the TRCV instruction in CPU_2 by using the
connection ID ("port ID 1") that was configured by the TCON instruction in CPU_1. The
TRCV instruction in CPU_2 links to the TSEND instruction in CPU_1 by using the
connection ID ("port ID 1") that was configured by the TCON instruction in CPU_2.
● The TSEND instruction in CPU_2 links to the TRCV instruction in CPU_1 by using the
connection ID ("port ID 1") that was configured by the TCON instruction in CPU_2. The
TRCV instruction in CPU_1 links to the TSEND instruction in CPU_2 by using the
connection ID ("port ID 1") that was configured by the TCON instruction in CPU_1.

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① TCON on CPU_1 creates a

connection and assigns a port ID for
that connection on CPU_1 (ID=1).

② TCON on CPU_2 creates a

connection and assigns a port ID for
that connection on CPU_2 (ID=1).

③ TSEND and TRCV on CPU_1 use the
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port ID created by the TCON on
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TSEND and TRCV on CPU_2 use the
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As shown in the following example, you can also use individual TSEND and TRCV
instruction to communication over a connection created by a TSEND_C or TRCV_C
instruction. The TSEND and TRCV instructions do not themselves create a new connection,
so must use the DB and port ID that was created by a TSEND_C, TRCV_C or TCON
instruction.

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PROFINET and PROFIBUS
11.2 PROFINET

&38B

① TSEND_C on CPU_1 creates a

connection and assigns a port ID to
that connection (ID=1).

② TRCV_C on CPU_2 creates a

connection and assigns the port ID to
that connection on CPU_2 (ID=1).

③ TSEND and TRCV on CPU_1 use the

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11.2.3

TSEND and TRCV on CPU_2 use the
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CPU_2 (ID=1).

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Protocols
The integrated PROFINET port of the CPU supports multiple communications standards
over an Ethernet network:
● Transport Control Protocol (TCP)
● ISO on TCP (RFC 1006)
● User Datagram Protocol (UDP)

Table 11- 1

Protocols and communication instructions for each

Protocol

Usage examples

Entering data in the
receive area

Communication
instructions

Addressing type

TCP

CPU-to-CPU
communication

Ad hoc mode

Only TRCV_C, and
TRCV

Transport of frames

Data reception with
specified length

TSEND_C, TRCV_C,
TCON, TDISCON,
TSEND, and TRCV

Assigns port numbers to
the Local (active) and
Partner (passive)
devices

CPU-to-CPU
communication

Ad hoc mode

Only TRCV_C and
TRCV

Message
fragmentation and reassembly

Protocol-controlled

TSEND_C, TRCV_C,
TCON, TDISCON,
TSEND, and TRCV

CPU-to-CPU
communication

User Datagram Protocol

TUSEND and TURCV

ISO on TCP

UDP

User program
communications

Assigns TSAPs to the
Local (active) and
Partner (passive)
devices
Assigns port numbers to
the Local (active) and
Partner (passive)
devices, but is not a
dedicated connection

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PROFINET and PROFIBUS
11.2 PROFINET

Protocol

Usage examples

Entering data in the
receive area

Communication
instructions

Addressing type

S7 communication

CPU-to-CPU
communication

Data transmission and
reception with specified
length

GET and PUT

Assigns TSAPs to the
Local (active) and
Partner (passive)
devices

Data transmission and
reception with specified
length

Built-in

Read/write data
from/to a CPU
PROFINET RT

11.2.4

CPU-to-PROFINET
IO device
communication

Ad hoc mode
Typically, TCP and ISO-on-TCP receive data packets of a specified length, ranging from 1 to
8192 bytes. However, the TRCV_C and TRCV communication instructions also provide an
"ad hoc" communications mode that can receive data packets of a variable length from 1 to
1472 bytes.
Note
If you store the data in an "optimized" DB (symbolic only), you can receive data only in
arrays of Byte, Char, USInt, and SInt data types.
To configure the TRCV_C or TRCV instruction for ad hoc mode, set the LEN parameter to
65535.
If you do not call the TRCV_C or TRCV instruction in ad hoc mode frequently, you could
receive more than one packet in one call. For example: If you were to receive five 100-byte
packets with one call, TCP would deliver these five packets as one 500-byte packet, while
ISO-on-TCP would restructure the packets into five 100-byte packets.

11.2.5

TCP and ISO on TCP
Transport Control Protocol (TCP) is a standard protocol described by RFC 793:
Transmission Control Protocol. The primary purpose of TCP is to provide reliable, secure
connection service between pairs of processes. This protocol has the following features:
● An efficient communications protocol since it is closely tied to the hardware
● Suitable for medium-sized to large data amounts (up to 8192 bytes)
● Provides considerably more facilities for applications, notably error recovery, flow control,
and reliability
● A connection-oriented protocol
● Can be used very flexibly with third-party systems which exclusively support TCP
● Routing-capable
● Only static data lengths are applicable.
● Messages are acknowledged.

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11.2 PROFINET
● Applications are addressed using port numbers.
● Most of the user application protocols, such as TELNET and FTP, use TCP.
● Programming effort is required for data management due to the SEND / RECEIVE
programming interface.
International Standards Organization (ISO) on Transport Control Protocol (TCP) (RFC 1006)
(ISO on TCP) is a mechanism that enables ISO applications to be ported to the TCP/IP
network. This protocol has the following features:
● An efficient communications protocol closely tied to the hardware
● Suitable for medium-sized to large data amounts (up to 8192 bytes)
● In contrast to TCP, the messages feature an end-of-data identification and are messageoriented.
● Routing-capable; can be used in WAN
● Dynamic data lengths are possible.
● Programming effort is required for data management due to the SEND / RECEIVE
programming interface.
Using Transport Service Access Points (TSAPs), TCP protocol allows multiple connections
to a single IP address (up to 64K connections). With RFC 1006, TSAPs uniquely identify
these communication end point connections to an IP address.

11.2.5.1

TSEND_C and TRCV_C
The TSEND_C instruction combines the functions of the TCON, TDISCON and TSEND
instructions. The TRCV_C instruction combines the functions of the TCON, TDISCON, and
TRCV instructions. (Refer to "TCON, TDISCON, TSEND, AND TRCV (Page 372)" for more
information on these instructions.)
The minimum size of data that you can transmit (TSEND_C) or receive (TRCV_C) is one
byte; the maximum size is 8192 bytes. TSEND_C does not support the transmission of data
or from boolean locations, and TRCV_C will not receive data into boolean locations. For
information transferring data with these instructions, see the section on data consistency
(Page 134).
Note
Initializing the communication parameters
After you insert the TSEND_C or TRCV_C instruction, use the "Properties" of the instruction
(Page 110) to configure the communication parameters (Page 113). As you enter the
parameters for the communication partners in the inspector window, STEP 7 enters the
corresponding data in the DB for the instruction.
If you want to use a multi-instance DB, you must manually configure the DB on both CPUs.

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Table 11- 2

TSEND_C and TRCV_C instructions

LAD / FBD

Description
TSEND_C establishes a TCP or ISO on TCP communication connection to a partner
station, sends data, and can terminate the connection. After the connection is set up and
established, it is automatically maintained and monitored by the CPU.

TRCV_C establishes a TCP or ISO on TCP communication connection to a partner CPU,
receives data, and can terminate the connection. After the connection is set up and
established, it is automatically maintained and monitored by the CPU.

STEP 7 automatically creates the DB when you insert the instruction.

Table 11- 3

TSEND_C and TRCV_C data types for the parameters

Parameter and type

Data type

Description

REQ

Bool

Control parameter REQ starts the send job with the connection
described in CONNECT on a rising edge.

Bool

Control parameter enabled to receive: When EN_R = 1,
TRCV_C is ready to receive. The receive job is processed.

Bool



0: Disconnect



1: Establish and hold connection

(TSEND_C)
EN_R
(TRCV_C)
CONT
LEN

UInt

Maximum number of bytes to be sent (TSEND_C) or received
(TRCV_C):


Default = 0: The DATA parameter determines the length of
the data to be sent (TSEND_C) or received (TRCV_C).



Ad hoc mode = 65535: A variable length of data is set for
reception (TRCV_C).

CONNECT

IN_OUT

TCON_Param

Pointer to the connection description (Page 113)

DATA

IN_OUT

Variant



Contains address and length of data to be sent (TSEND_C)



Contains start address and maximum length of received
data (TRCV_C).

COM_RST

IN_OUT

Bool

Allows restart of the instruction:


0: Irrelevant



1: Complete restart of the function block, existing connection
will be terminated.

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Parameter and type

Data type

Description

DONE

Bool



0: Job is not yet started or still running.



1: Job completed without error.



0: Job is completed.



1: Job is not yet completed. A new job cannot be triggered.

BUSY
ERROR

OUT
OUT
OUT

Bool
Bool

Status parameters with the following values:


0: No error



1: Error occurred during processing. STATUS provides
detailed information on the type of error.

STATUS

OUT

Word

Status information including error information. (Refer to the
"Error and Status Parameters" table below.)

RCVD_LEN

OUT

Int

Amount of data actually received, in bytes

(TRCV_C)

Note
The default setting of the LEN parameter (LEN = 0) uses the DATA parameter to determine
the length of the data being transmitted. Ensure that the DATA transmitted by the TSEND_C
instruction is the same size as the DATA parameter of the TRCV_C instruction.

TSEND_C operations
The following functions describe the operation of the TSEND_C instruction:
● To establish a connection, execute TSEND_C with CONT = 1.
● After successful establishing of the connection, TSEND_C sets the DONE parameter for
one cycle.
● To terminate the communication connection, execute TSEND_C with CONT = 0. The
connection will be aborted immediately. This also affects the receiving station. The
connection will be closed there and data inside the receive buffer could be lost.
● To send data over an established connection, execute TSEND_C with a rising edge on
REQ. After a successful send operation, TSEND_C sets the DONE parameter for one
cycle.
● To establish a connection and send data, execute TSEND_C with CONT =1 and REQ =
1. After a successful send operation, TSEND_C sets the DONE parameter for one cycle.

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TRCV_C operations
The following functions describe the operation of the TRCV_C instruction:
● To establish a connection, execute TRCV_C with parameter CONT = 1.
● To receive data, execute TRCV_C with parameter EN_R = 1. TRCV_C receives the data
continuously when parameters EN_R = 1 and CONT = 1.
● To terminate the connection, execute TRCV_C with parameter CONT = 0. The
connection will be aborted immediately, and data could be lost.
TRCV_C handles the same receive modes as the TRCV instruction. The following table
shows how data is entered in the receive area.
Table 11- 4

Entering the data into the receive area

Protocol
variant

Entering the data in the Parameter
receive area
"connection_type"

Value of the LEN parameter

Value of the RCVD_LEN
parameter (bytes)

TCP

Ad hoc mode

B#16#11

65535

1 to 1472

TCP

Data reception with
specified length

B#16#11

0 (recommended) or 1 to
8192, except 65535

1 to 8192

ISO on TCP

Ad hoc mode

B#16#12

65535

1 to 1472

ISO on TCP

Protocol-controlled

B#16#12

0 (recommended) or 1 to
8192, except 65535

1 to 8192

Note
Ad hoc mode
The "ad hoc mode" exists with the TCP and ISO on TCP protocol variants. You set "ad hoc
mode" by assigning "65535" to the LEN parameter. The receive area is identical to the area
formed by DATA. The length of the received data will be output to the parameter
RCVD_LEN.
If you store the data in an "optimized" DB (symbolic only), you can receive data only in
arrays of Byte, Char, USInt, and SInt data types.
Note
Importing of S7-300/400 STEP 7 projects containing "ad hoc mode" into the S7-1200
In S7-300/400 STEP 7 projects, "ad hoc mode" is selected by assigning "0" to the LEN
parameter. In the S7-1200, you set "ad hoc mode" by assigning "65535" to the LEN
parameter.
If you import an S7-300/400 STEP 7 project containing "ad hoc mode" into the S7-1200, you
must change the LEN parameter to "65535".

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Note
Due to the asynchronous processing of TSEND_C, you must keep the data in the sender
area consistent until the DONE parameter or the ERROR parameter assumes the value
TRUE.
For TSEND_C, a TRUE state at the parameter DONE means that the data was sent
successfully. It does not mean that the connection partner CPU actually read the receive
buffer.
Due to the asynchronous processing of TRCV_C, the data in the receiver area are only
consistent when parameter DONE = 1.

Table 11- 5

TSEND_C and TRCV_C instructions BUSY, DONE, and ERROR parameters

BUSY

DONE

ERROR

Description

TRUE

irrelevant

The job is being processed.

FALSE

TRUE

FALSE

The job is successfully completed.

FALSE

TRUE

The job was ended with an error. The cause of the error can be found
in the STATUS parameter.

FALSE

A new job was not assigned.

Error and Status Parameters
Table 11- 6

TSEND_C and TRCV_C condition codes for ERROR and STATUS

ERROR

STATUS

Description

0000

Job executed without error

7000

No job processing active

7001

Start job processing, establishing connection, waiting for connection partner

7002

Data being sent or received

7003

Connection being terminated

7004

Connection established and monitored, no job processing active

8085

LEN parameter is greater than the largest permitted value.

8086

The CONNECT parameter is outside the permitted range.

8087

Maximum number of connections reached; no additional connection possible.

8088

LEN parameter is not valid for the memory area specified in DATA.

8089

The CONNECT parameter does not point to a data block.

8091

Maximum nesting depth exceeded.

809A

The CONNECT parameter points to a field that does not match the length of the
connection description.

809B

The local_device_id in the connection description does not match the CPU.

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ERROR

STATUS

Description

80A1

Communications error:


The specified connection was not yet established



The specified connection is currently being terminated; transmission over this
connection is not possible



The interface is being reinitialized

80A3

Attempt being made to terminate a nonexistent connection

80A4

IP address of the remote partner connection is invalid. For example, the remote partner
IP address is the same as the local partner IP address.

80A7

Communications error: You called TDISCON before TSEND_C was complete.

80B2

The CONNECT parameter points to a data block that was generated with the keyword
UNLINKED.

80B3

Inconsistent parameters:

80B4



Error in the connection description



Local port (parameter local_tsap_id) is already present in another connection
description.



ID in the connection description different from the ID specified as parameter

When using the ISO on TCP (connection_type = B#16#12) to establish a passive
connection, condition code 80B4 alerts you that the TSAP entered did not conform to
one of the following address requirements:


For a local TSAP length of 2 and a TSAP ID value of either E0 or E1 (hexadecimal)
for the first byte, the second byte must be either 00 or 01.



For a local TSAP length of 3 or greater and a TSAP ID value of either E0 or E1
(hexadecimal) for the first byte, the second byte must be either 00 or 01 and all
other bytes must be valid ASCII characters.

For a local TSAP length of 3 or greater and the first byte of the TSAP ID does not
have a value of either E0 or E1 (hexadecimal), then all bytes of the TSAP ID must
be valid ASCII characters.
Valid ASCII characters are byte values from 20 to 7E (hexadecimal).


80B7

Data type and/or length of the transmitted data does not fit in the area in the partner
CPU in which it is to be written.

80C3

All connection resources are in use.

80C4

Temporary communications error:


The connection cannot be established at this time



The interface is receiving new parameters



The configured connection is currently being removed by a TDISCON.

8722

CONNECT parameter: Source area invalid: area does not exist in DB.

873A

CONNECT parameter: Access to connection description is not possible (for example,
DB not available)

877F

CONNECT parameter: Internal error such as an invalid ANY reference

893A

Parameter contains the number of a DB that is not loaded.

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Connection Ethernet protocols
Every CPU has an integrated PROFINET port, which supports standard PROFINET
communications. The TSEND_C and TRCV_C and TSEND and TRCV instructions all
support the TCP and ISO on TCP Ethernet protocols.
Refer to "Device Configuration: Configuring the Local/Partner connection path (Page 110)"
for more information.

11.2.5.2

TCON, TDISCON, TSEND, AND TRCV

Ethernet communication using TCP and ISO on TCP protocols
Note
TSEND_C and TRCV_C instructions
To help simplify the programming of PROFINET/Ethernet communication, the TSEND_C
instruction and the TRCV_C instruction combine the functionality of the TCON, TDISCON.
TSEND and TRCV instructions:
 TSEND_C combines the TCON, TDISCON and TSEND instructions.
 TRCV_C combines the TCON, TDISCON and TRCV instructions.
The following instructions control the communication process:
● TCON establishes the TCP/IP connection between the client and server (CPU) PC.
● TSEND and TRCV send and receive data.
● TDISCON breaks the connection.
The minimum size of data that you can transmit (TSEND) or receive (TRCV) is one byte; the
maximum size is 8192 bytes. TSEND does not support the transmission of data or from
boolean locations, and TRCV will not receive data into boolean locations. For information
transferring data with these instructions, see the section on data consistency (Page 134).
TCON, TDISCON, TSEND, and TRCV operate asynchronously, which means that the job
processing extends over multiple instruction executions. For example, you start a job for
setting up and establishing a connection by executing an instruction TCON with parameter
REQ = 1. Then you use additional TCON executions to monitor the job progress and test for
job completion with parameter DONE.
The following table shows the relationships between BUSY, DONE, and ERROR. Use the
table to determine the current job status.
Table 11- 7

Interactions between the BUSY, DONE, and ERROR parameters

BUSY

DONE

ERROR

Description

TRUE

irrelevant

The job is being processed.

FALSE

TRUE

FALSE

The job successfully completed.

FALSE

TRUE

The job was ended with an error. The cause of the error can be found in the
STATUS parameter.

FALSE

A new job was not assigned.
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TCON and TDISCON
Note
Initializing the communication parameters
After you insert the TCON instruction, use the "Properties" of the instruction (Page 110) to
configure the communication parameters (Page 113). As you enter the parameters for the
communication partners in the inspector window, STEP 7 enters the corresponding data in
the instance DB for the instruction.
If you want to use a multi-instance DB, you must manually configure the DB on both CPUs.

Table 11- 8

TCON and TDISCON instructions

LAD / FBD

Description
TCP and ISO on TCP: TCON initiates a communications connection from the CPU to a
communication partner.

TCP and ISO on TCP: TDISCON terminates a communications connection from the CPU
to a communication partner.

STEP 7 automatically creates the DB when you insert the instruction.

Table 11- 9

Data types for the parameters of TCON and TDISCON

Parameter and type

Data type

Description

REQ

Bool

Control parameter REQ starts the job by establishing the
connection specified by ID. The job starts at rising edge.

CONN_OUC (Word)

Reference to the connection to be established (TCON) or
terminated (TDISCON) to the remote partner, or between
the user program and the communication layer of the
operating system. The ID must be identical to the
associated parameter ID in the local connection description.
Value range: W#16#0001 to W#16#0FFF

CONNECT

IN_OUT

TCON_Param

Pointer to the connection description (Page 113)

(TCON)

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Parameter and type
DONE
BUSY

ERROR

STATUS

OUT
OUT

OUT

Data type

Description

Bool



0: Job is not yet started or still running.



1: Job completed without error.



0: Job is completed.



1: Job is not yet completed. A new job cannot be
triggered.

Bool

Word

Status parameters with the following values:


0: No error



1: Error occurred during processing. STATUS provides
detailed information on the type of error.

Status information including error information. (Refer to the
Error and Status condition codes in the table below.)

Both communication partners execute the TCON instruction to set up and establish the
communication connection. You use parameters to specify the active and passive
communication end point partners. After the connection is set up and established, it is
automatically maintained and monitored by the CPU.
If the connection is terminated due to a line break or due to the remote communications
partner, for example, the active partner attempts to re-establish the configured connection.
You do not have to execute TCON again.
An existing connection is terminated and the set-up connection is removed when the
TDISCON instruction is executed or when the CPU has gone into STOP mode. To set up
and re-establish the connection, you must execute TCON again.
Table 11- 10 ERROR and STATUS condition codes for TCON and TDISCON
ERROR

STATUS

Description

0000

Connection was established successfully.

7000

No job processing active

7001

Start job processing; establishing connection (TCON) or terminating connection
(TDISCON)

7002

Follow-on call (REQ irrelevant); establishing connection (TCON) or terminating
connection (TDISCON)

8086

The ID parameter is outside the permitted address range.

8087

TCON: Maximum number of connections reached; no additional connection possible.

809B

TCON: The local_device_id in the connection description does not match the CPU.

80A1

TCON: Connection or port is already occupied by user.

80A2

TCON: Local or remote port is occupied by the system.

80A3

Attempt being made to re-establish an existing connection (TCON) or terminate a nonexistent connection (TDISCON).

80A4

TCON: IP address of the remote connection end point is invalid; it may match the local
IP address.

80A7

TCON: Communications error: you executed TDISCON before TCON was complete.
TDISCON must first completely terminate the connection referenced by the ID.

()

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ERROR

STATUS

Description

80B4

TCON: When using the ISO on TCP (connection_type = B#16#12) to establish a
passive connection, condition code 80B4 alerts you that the TSAP entered did not
conform to one of the following address requirements:


For a local TSAP length of 2 and a TSAP ID value of either E0 or E1 (hexadecimal)
for the first byte, the second byte must be either 00 or 01.



80B6

TCON: Parameter assignment error in parameter connection_type

80B7

TCON: Data type and/or length of the transmitted data does not fit in the area in the
partner CPU, in which it is to be written.

80B8

TCON: Parameter in the local connection description and Parameter ID are different.

80C3

TCON: All connection resources are in use.

80C4

Temporary communications error:


The connection cannot be established at this time (TCON).



The configured connection is currently being removed by TDISCON (TCON).



The connection is currently being established (TDISCON).



The interface is receiving new parameters (TCON and TDISCON).

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TSEND and TRCV
Table 11- 11 TSEND and TRCV instructions
LAD / FBD

Description
TCP and ISO on TCP: TSEND sends data through a communication connection from the
CPU to a partner station.

TCP and ISO on TCP: TRCV receives data through a communication connection from a
partner station to the CPU.

STEP 7 automatically creates the DB when you insert the instruction.

Table 11- 12 Data types for the parameters of TSEND and TRCV
Parameter and type

Data type

Description

REQ

Bool

TEND: Starts the send job on a rising edge. The data is
transferred from the area specified by DATA and LEN.

EN_R

Bool

TRCV: Enables the CPU to receive; with EN_R = 1, the TRCV is
ready to receive. The receive job is processed.

CONN_OUC
(Word)

Reference to the associated connection. ID must be identical to
the associated parameter ID in the local connection description.

LEN

UInt

Value range: W#16#0001 to W#16#0FFF
Maximum number of bytes to be sent (TSEND) or received
(TRCV):


Default = 0: The DATA parameter determines the length of the
data to be sent (TSEND) or received (TRCV).



Ad hoc mode = 65535: A variable length of data is set for
reception (TRCV).

DATA

IN_OUT

Variant

Pointer to send (TSEND) or receive (TRCV) data area; data area
contains the address and length. The address refers to I memory,
Q memory, M memory, or a DB.

DONE

OUT

Bool

TSEND:


0: Job not yet started or still running.



1: Job executed without error.

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Parameter and type

Data type

Description

NDR

Bool

TRCV:

BUSY

OUT

Bool



NDR = 0: Job not yet started or still running.



NDR = 1: Job successfully completed.



BUSY = 1: The job is not yet complete. A new job cannot be
triggered.



BUSY = 0: Job is complete.

ERROR

OUT

Bool

ERROR = 1: Error occurred during processing. STATUS provides
detailed information on the type of error

STATUS

OUT

Word

Status information including error information. (Refer to the Error
and Status condition codes in the table below.)

RCVD_LEN

OUT

Int

TRCV: Amount of data actually received in bytes

TRCV Operations
The TRCV instruction writes the received data to a receive area that is specified by the
following two variables:
● Pointer to the start of the area
● Length of the area
Note
The default setting of the LEN parameter (LEN = 0) uses the DATA parameter to
determine the length of the data being transmitted. Ensure that the DATA transmitted by
the TSEND instruction is the same size as the DATA parameter of the TRCV instruction.
As soon as all the job data has been received, TRCV transfers it to the receive area and sets
NDR to 1.
Table 11- 13 Entering the data into the receive area
Protocol
variant

Entering the data in the Parameter
receive area
"connection_type"

Value of the LEN parameter

Value of the RCVD_LEN
parameter (bytes)

TCP

Ad hoc mode

B#16#11

65535

1 to 1472

TCP

Data reception with
specified length

B#16#11

0 (recommended) or 1 to
8192, except 65535

1 to 8192

ISO on TCP

Ad hoc mode

B#16#12

65535

1 to 1472

ISO on TCP

protocol-controlled

B#16#12

0 (recommended) or 1 to
8192, except 65535

1 to 8192

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Note
Ad hoc mode
The "ad hoc mode" exists with the TCP and ISO on TCP protocol variants. You set "ad hoc
mode" by assigning "65535" to the LEN parameter. The receive area is identical to the area
formed by DATA. The length of the received data will be output to the parameter
RCVD_LEN. Immediately after receiving a block of data, TRCV enters the data in the receive
area and sets NDR to 1.
If you store the data in an "optimized" DB (symbolic only), you can receive data only in
arrays of Byte, Char, USInt, and SInt data types.
Note
Importing of S7-300/400 STEP 7 projects containing "ad hoc mode" into the S7-1200
In S7-300/400 STEP 7 projects, "ad hoc mode" is selected by assigning "0" to the LEN
parameter. In the S7-1200, you set "ad hoc mode" by assigning "65535" to the LEN
parameter.
If you import an S7-300/400 STEP 7 project containing "ad hoc mode" into the S7-1200, you
must change the LEN parameter to "65535".

Table 11- 14 ERROR and STATUS condition codes for TSEND and TRCV
ERROR

STATUS

Description

0000



Send job completed without error (TSEND)



New data accepted: The current length of the received data is shown in RCVD_LEN
(TRCV).



No job processing active (TSEND)



Block not ready to receive (TRCV)



Start of job processing, data being sent: During this processing the operating
system accesses the data in the DATA send area (TSEND).



Block is ready to receive, receive job was activated (TRCV).



Follow-on instruction execution (REQ irrelevant), job being processed: The
operating system accesses the data in the DATA send area during this processing
(TSEND).



Follow-on instruction execution, receive job being processed: Data is written to the
receive area during this processing. For this reason, an error could result in
inconsistent data in the receive area (TRCV).



LEN parameter is greater than the largest permitted value (TSEND) and (TRCV).



LEN or DATA parameter changed since the first instruction execution (TRCV).

0
0

7000
7001

7002

8085

8086

The ID parameter is not in the permitted address range.

8088

The LEN parameter is larger than the memory area specified in DATA.

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ERROR

STATUS

Description

80A1

Communications error:


The specified connection has not yet established (TSEND and TRCV).



The specified connection is currently being terminated. Transmission or a receive
job over this connection is not possible (TSEND and TRCV).



The interface is being reinitialized (TSEND).



The interface is receiving new parameters (TRCV).

80C3

Internal lack of resources: A block with this ID is already being processed in a different
priority class.

80C4

Temporary communications error:


The connection to the communications partner cannot be established at this time.



The interface is receiving new parameter settings, or the connection is currently
being established.

Connection Ethernet protocols
Every CPU has an integrated PROFINET port, which supports standard PROFINET
communications. The TSEND_C, TRCV_C, TSEND and TRCV instructions all support the
TCP and ISO on TCP Ethernet protocols.
Refer to "Device Configuration: Configuring the Local/Partner connection path (Page 110)"
for more information.

11.2.6

UDP
UDP is a standard protocol described by RFC 768: User Datagram Protocol. UDP provides a
mechanism for one application to send a datagram to another; however, delivery of data is
not guaranteed. This protocol has the following features:
● A quick communications protocol, because it is very hardware-intimate
● Suitable for small-sized to medium data amounts (up to 2048 bytes)
● UDP is a simpler transport control protocol than TCP, with a thin layer that yields low
overheads
● Can be used very flexibly with many third-party systems
● Routing-capable
● Uses port numbers to direct the datagrams
● Messages are unacknowledged: The application is required to take responsibility for error
recovery and security
● Programming effort is required for data management due to the SEND / RECEIVE
programming interface
UDP supports broadcast communication. To use broadcast, you must configure the IP
address portion of the ADDR configuration. For example: A CPU with an IP address of
192.168.2.10 and seubnet mask of 255.255.255.0 would use a broadcast address of
192.168.2.255.

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11.2.6.1

TUSEND and TURCV
The following instructions control the UDP communication process:
● TCON establishes the communication between the client and server (CPU) PC.
● TUSEND and TURCV send and receive data.
● TDISCON disconnects the communication between the client and server.
Refer to TCON, TDISCON, TSEND, and TRCV (Page 372) in the "TCP and ISO-on-TCP"
section for more information on the TCON and TDISCON communication instructions.

Table 11- 15 TUSEND and TURCV instructions
LAD / FBD

Description
The TUSEND instruction sends data via UDP to the remote partner specified by the
parameter ADDR.
To start the job for sending data, call the TUSEND instruction with REQ = 1.

The TURCV instruction receives data via UDP. The parameter ADDR shows the address
of the sender. After successful completion of TURCV, the parameter ADDR contains the
address of the remote partner (the sender).
TURCV does not support ad hoc mode.
To start the job for receiving data, call the TURCV instruction with EN_R = 1.

STEP 7 automatically creates the DB when you insert the instruction.

TCON, TDISCON, TUSEND, and TURCV operate asynchronously, which means that the job
processing extends over multiple instruction executions.
Table 11- 16 TUSEND and TURCV data types for the parameters
Parameter and type

Data type

Description

REQ

Bool

Starts the send job on a rising edge. The data is transferred from
the area specified by DATA and LEN.

Bool



0: CPU cannot receive.



1: Enables the CPU to receive. The TURCV instruction is
ready to receive, and the receive job is processed.

(TUSEND)
EN_R
(TURCV)
ID

Word

Reference to the associated connection between the user
program and the communication level of the operating system.
ID must be identical to the associated parameter ID in the local
connection description.
Range of values: W#16#0001 to W#16#0FFF.

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Parameter and type

Data type

Description

LEN

UInt

Number of bytes to be sent (TUSEND) or received (TURCV).

DONE

Bool

(TUSEND)
NDR

OUT

Bool

(TURCV)
BUSY
ERROR

OUT
OUT

Bool
Bool



Default = 0. The DATA parameter determines the length of
the data to be sent or received.



Otherwise, range of values: 1 to 1472

Status parameter DONE (TUSEND):


0: Job is not yet started or still running.



1: Job completed without error.

Status parameter NDR (TURCV):


0: Job not yet started or still running.



1: Job has successfully completed.



1: Job is not yet completed. A new job cannot be triggered.



0: Job has completed.

Status parameters with the following values:


0: No error



1: Error occurred during processing. STATUS provides
detailed information on the type of error.

STATUS

OUT

Word

Status information including error information. (Refer to the Error
and Status condition codes in the table below.)

DATA

IN_OUT

Variant

Address of the sender area (TUSEND) or receive area
(TURCV):

ADDR

IN_OUT

Variant



The process image input table



The process image output table



A memory bit



A data block

Pointer to the address of the receiver (for TUSEND) or sender
(for TURCV) (for example, P#DB100.DBX0.0 byte 8). The
pointer may point to any memory area.
A structure of 8 bytes is required as follows:


First 4 bytes contain the remote IP address.



Next 2 bytes specify the remote port number.



Last 2 bytes are reserved.

The job status is indicated at the output parameters BUSY and STATUS. STATUS
corresponds to the RET_VAL output parameter of asynchronously functioning instructions.
The following table shows the relationships between BUSY, DONE (TUSEND), NDR
(TURCV), and ERROR. Using this table, you can determine the current status of the
instruction (TUSEND or TURCV) or when the sending (transmission) / receiving process is
complete.

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Table 11- 17 Status of BUSY, DONE (TUSEND) / NDR (TURCV), and ERROR parameters
BUSY

DONE / NDR

ERROR

Description

TRUE

irrelevant

The job is being processed.

FALSE

TRUE

FALSE

The job was completed successfully.

FALSE

TRUE

The job was ended with an error. The cause of the error can be
found in the STATUS parameter..

FALSE

The instruction was not assigned a (new) job.

Due to the asynchronous function of the instructions: For TUSEND, you must keep the data in the sender area
consistent until the DONE parameter or the ERROR parameter assumes the value TRUE. For TURCV, the data in the
receiver area are only consistent when the NDR parameter assumes the value TRUE.

Table 11- 18 TUSEND and TURCV condition codes for ERROR and STATUS
ERROR

STATUS

Description

0000



Send job completed without error (TUSEND).



New data were accepted. The current length of the received data is shown in
RCVD_LEN (TURCV).



No job processing active (TUSEND)



Block not ready to receive (TURCV)



Start of job processing, data being sent (TUSEND): During this processing, the
operating system accesses the data in the DATA send area.



Block is ready to receive, receive job was activated (TURCV).



Follow-on instruction execution (REQ irrelevant), job being processed (TUSEND):
During this processing, the operating system accesses the data in the DATA send
area.



Follow-on instruction execution, job being processed: During this processing, the
TURCV instruction writes data to the receive area. For this reason, an error could
result in inconsistent data in the receive area.

0
0

7000
7001

7002

8085

LEN parameter is greater than the largest permitted value, has the value 0 (TUSEND),
or you changed the value of the LEN or DATA parameter since the first instruction
execution (TURCV).

8086

The ID parameter is not in the permitted address range.

8088



LEN parameter is larger than the memory area (TUSEND) or receive area (TURCV)
specified in DATA.



Receive area is too small (TURCV).

8089

ADDR parameter does not point to a data block.

80A1

Communications error:


The specified connection between user program and communications layer of the
operating system has not yet been established.



The specified connection between the user program and the communication layer of
the operating system is currently being terminated. Transmission (TUSEND) or a
receive job (TURCV) over this connection is not possible.



The interface is being reinitialized.

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ERROR

STATUS

Description

80A4

IP address of the remote connection end point is invalid; it is possible that it matches
the local IP address (TUSEND).

80B3



The set protocol variant (connection_type parameter in the connection description)
is not UDP. Please use the TSEND or TRCV instruction.



ADDR parameter: Invalid settings for port number (TUSEND)



A block with this ID is already being processed in a different priority class.



Internal lack of resources

1
1

80C3
80C4

Temporary communications error:


The connection between the user program and the communication level of the
operating system cannot be established at this time (TUSEND).



The interface is receiving new parameters (TUSEND).



The connection is currently being reinitiated (TURCV).

Connection Ethernet protocols
Every CPU has an integrated PROFINET port, which supports standard PROFINET
communications. The TUSEND and TURCV instructions support the UDP Ethernet protocol.
Refer to "Configuring the Local/Partner connection path" (Page 110)" in the "Device
configuration" chapter for more information.

Operations
Both partners are passive in UDP communication. Typical parameter start values for the
"TCON_Param" data type are shown in the following table. Port numbers (LOCAL_TSAP_ID)
are written in a 2-byte format. All ports except for 161, 34962, 34963, and 34964 are
allowed.
Table 11- 19 "TCON_Param" data type parameter values
TCON instruction

TCON "UDP Conn DB"

The TUSEND instruction sends data through UDP to the remote partner specified in the
"TADDR_Param" data type. The TURCV instruction receives data through UDP. After a
successful execution of the TURCV instruction, the "TADDR_Param" data type shows the
address of the remote partner (the sender).

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Table 11- 20 "TADDR_Param" data type parameter values
TUSEND instruction

11.2.7

TUSEND "UDP ADDR DB"

T_CONFIG
The T_CONFIG instruction changes the IP configuration parameters of the PROFINET port
from the user program, allowing the temporary or permanent change or setting of the
following features:
● Station name
● IP address
● Subnet mask
● Router address
WARNING
After you use the T_CONFIG to change an IP configuration parameter, the CPU
restarts. The CPU will go to STOP mode and then proceed to the configured startup
mode: "No restart (stay in STOP mode)", "Warm restart - RUN", or "Warm restart mode before power off".
Control devices can fail in an unsafe condition, resulting in unexpected operation of
controlled equipment. Such unexpected operations could result in death or serious injury
to personnel, and/or damage to equipment.
Ensure that your process will go to a safe state when the CPU restarts as a result of
T_CONFIG instruction execution.

Table 11- 21 T_CONFIG instruction
LAD / FBD

Description
Use the T_CONFIG instruction to change the IP configuration parameters from your user
program.
T_CONFIG works asynchronously. The execution extends over multiple calls.

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Table 11- 22 Data types for the parameters
Parameter and type

Data type

REQ

Input

Bool

Starts the instruction on the rising edge.

INTERFACE

Input

HW_Interface

ID of network interface

CONF_DATA

Input

Variant

Reference to the structure of the configuration data;
CONF_DATA is defined by a System Data Type (SDT).

DONE

Output

Bool



0: Job has not yet started or is still running.



1: Job was executed without error.



0: The job is complete.



1: The job is not yet complete. A new job cannot be
triggered.

BUSY

ERROR

Output

Bool

Output

Bool

Description

Status parameters with the following values:


0: No error



1: Error occurred during processing. STATUS provides
detailed information on the type of error.

STATUS

Output

DWord

Status information including error information. (Refer to
the Error and Status condition codes in the table below.)

ERR_LOC

Output

DWord

Fault location (field ID and subfield ID of the error
parameter)

The IP configuration information is placed in the CONF_DATA data block, along with a
Variant pointer on parameter CONF_DATA referenced above. The successful execution of
the T_CONFIG instruction ends with the handover of the IP configuration data to the network
interface. Errors, such as conflicts between IP addresses, are assigned to the diagnostic
buffer and written to the diagnostics buffer.
Table 11- 23 Condition codes for ERROR and STATUS
ERROR

STATUS

Description

00000000

No error

00700000

The job is not finished (BUSY = 1).

00700100

Start of job execution

00700200

Intermediate call (REQ irrelevant)

C08xyy00

General failure

C0808000

LADDR parameters for identification of the interface are invalid.

C0808100

LADDR parameters for identification of the interface have been assigned a non-supported
hardware interface.

C0808200

CONF_DATA parameter error: Data type of the Variant pointer does not match the data
type Byte.

C0808300

CONF_DATA parameter error: The area pointer is not in the DB of the Variant pointer.

C0808400

CONF_DATA parameter error: The Variant pointer is the wrong length.

C0808600

Reserved

C0808700

Inconsistency in the CONF_DATA data block length to the IP configuration

C0808800

The parameters of the CONF_DATA data block field_type_id are invalid. (Only
field_type_id = 0 is allowed.)

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ERROR

STATUS

Description

C0808900

The parameters of the CONF_DATA data block field_type_id are invalid or have been
used several times.

C0808A00

LEN length of the IP configuration parameters or subfield_cnt errors

C0808B00

The IP configuration ID parameter is invalid or unsupported.

C0808C00

The Sub-block of the IP configuration is incorrectly placed (Sub-block wrong, wrong order,
or used multiple times).

C0808D00

The length of a statement LEN Sub-blocks is invalid.

C0808E00

The value of the parameter in Sub-blocks mode is invalid.

C0808F00

Sub-block conflict between the IP configuration and a previous Sub-block.

C0809000

The parameters of the subfield are write-protected (for example: parameters are specified
by configuration, or PNIO mode is enabled).

C0809100

Reserved

C0809400

A parameter in the Sub-block IP configuration has not been defined or may not be used.

C0809500

There is an inconsistency between a parameter of the Sub-block IP configuration and
other parameters.

C080C200

Instruction cannot be executed. This error can occur if, for example, communication with
the interface has been lost.

C080C300

There are not enough resources. This error can occur if, for example, the instruction is
called multiple times with different parameters

C080C400

Communication failure. The error can occur temporarily and will require a repeat of the
user program.

C080D200

Execution of the instruction is not supported by the PROFINET interface.

11.2.7.1

CONF_DATA Data block
The following diagram shows how the configuration data to be transferred is stored in the
configuration DB.
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Configuration DB
Configuration data
Subfield 1

④
⑤
⑥

Subfield 2
Subfield n
Subfield-specific parameters

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The configuration data of CONF_DB consists of a field that contains a header
(IP_CONF_Header) and several subfields. IP_CONF_Header provides the following
elements:
● field_type_id (data type UInt): Zero
● field_id (data type UInt): Zero
● subfield_cnt (data type UInt): Number of subfields
Each subfield consists of a header (subfield_type_id, subfield_length, subfield_mode) and
the subfield-specific parameters. Each subfield must consist of an even number of bytes.
The subfield_mode supports a value of 1 (permanent validity of the configuration data)
Note
Only one field (IP_CONF_Header) is currently allowed. Its parameters field_type_id and
field_id must have the value zero. Other fields with different values for field_type_id and
field_id are subject to future extensions.

Table 11- 24 Subfields supported
subfield_type_id

Data type

Explanation

IF_CONF_V4

IP parameters: IP address, subnet mask, router address

IF_CONF_NOS

PROFINET IO device name (Name of Station)

Table 11- 25 Elements of the IF_CONF_V4 data type
Name

Data type

Start value

Description

UInt

subfield_type_id

len

UInt

subfield_length

mode

UInt

subfield_mode (1: permanent)

InterfaceAddress

IP_V4

Interface address

ADDR

Array [1..4] of Byte

ADDR[1]

Byte

b#16#C8

IP address high byte: 200

ADDR[2]

Byte

b#16#0C

IP address high byte: 12

ADDR[3]

Byte

b#16#01

IP address low byte: 1

ADDR[4]

Byte

b#16#90

IP address low byte: 144

IP_V4

Subnet mask

SubnetMask
ADDR

Array [1..4] of Byte

ADDR[1]

Byte

b#16#FF

Subnet mask high byte: 255

ADDR[2]

Byte

b#16#FF

Subnet mask high byte: 255

ADDR[3]

Byte

b#16#FF

Subnet mask low byte: 255

ADDR[4]

Byte

b#16#00

Subnet mask low byte: 0

DefaultRouter

IP_V4

Default router

ADDR

Array [1..4] of Byte

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Name

Data type

Start value

Description

ADDR[1]

Byte

b#16#C8

Router high byte: 200

ADDR[2]

Byte

b#16#0C

Router high byte: 12

ADDR[3]

Byte

b#16#01

Router low byte: 1

ADDR[4]

Byte

b#16#01

Router low byte: 1

Table 11- 26 Elements of the IF_CONF_NOS data type
Name

Data type

Start value

Description

UInt

subfield_type_id

len

UInt

246

subfield_length

mode

UInt

subfield_mode (1: permanent)

Nos (Name of
Station)

Array[1..240]
of Byte

Station name: You must occupy the ARRAY from the first byte. If
the ARRAY is longer than the station name to be assigned, you
must enter a zero byte after the actual station name (in
conformity with IEC 61158-6-10). Otherwise, nos is rejected and
the "T_CONFIG and TC_CONFIG (Page 384)" instructions enter
the error code DW#16#C0809400 in STATUS. If you occupy the
first byte with zero, the station name is deleted.

The station name is subject to the following limitations:
● Restricted to a total of 240 characters (lower case letters, numbers, dash, or dot)
● A name component within the station name, i.e., a character string between two dots,
must not exceed 63 characters.
● No special characters such as umlauts, brackets, underscore, slash, blank space, etc.
The only special character permitted is the dash.
● The station name must not begin or end with the "-" character.
● The station name must not begin with a number.
● The station name form n.n.n.n (n = 0, ... 999) is not permitted.
● The station name must not begin with the string "port-xyz" or "port-xyz-abcde" (a, b, c, d,
e, x, y, z = 0, ... 9).
Note
You can also create an ARRAY "nos" that is shorter then 240 bytes, but not less than 2
bytes. In this case, you must adjust the "len" (length of subfield) tag accordingly.

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11.2.8

Common parameters for instructions

REQ input parameter
Many of the Open User Communication instructions use the REQ input to initiate the
operation on a low to high transition. The REQ input must be high (TRUE) for one execution
of an instruction, but the REQ input can remain TRUE for as long as desired. The instruction
does not initiate another operation until it has been executed with the REQ input FALSE so
that the instruction can reset the history state of the REQ input. This is required so that the
instruction can detect the low to high transition to initiate the next operation.
When you place one of these instructions in your program, STEP 7 prompts you to identify
the instance DB. Use a unique DB for each instruction call. This ensures that each
instruction properly handles inputs such as REQ.

ID input parameter
This is a reference to the "Local ID (hex)" on the "Network view" of "Devices and networks"
in STEP 7 and is the ID of the network that you want to use for this communication block.
The ID must be identical to the associated parameter ID in the local connection description.

DONE, NDR, ERROR, and STATUS output parameters
These instructions provide outputs describing the completion status:
Table 11- 27 Open User Communication instruction output parameters
Parameter

Data type

Default

Description

DONE

Bool

FALSE

Is set TRUE for one execution to indicate that the last request
completed without errors; otherwise, FALSE.

NDR

Bool

FALSE

Is set TRUE for one execution to indicate that the requested action
has completed without error and new data has been received;
otherwise, FALSE.

BUSY

Bool

FALSE

Is set TRUE when active to indicate that:


The job is not yet complete.

 A new job cannot be triggered.
Is set FALSE when job is complete.
ERROR

Bool

FALSE

Is set TRUE for one execution to indicate that the last request
completed with errors, with the applicable error code in STATUS;
otherwise, FALSE.

STATUS

Word

Result status:


If the DONE or NDR bit is set, then STATUS is set to 0 or to an
informational code.



If the ERROR bit is set, then STATUS is set to an error code.

If none of the above bits are set, then the instruction returns
status results that describe the current state of the function.
STATUS retains its value for the duration of the execution of the
function.


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Note
Note that DONE, NDR, and ERROR are set for one execution only.

Restricted TSAPs and port numbers for passive ISO and TCP communication
If you use the "TCON" instruction to set up and establish a passive communications
connection, the following port addresses are restricted and should not be used:
● ISO TSAP (passive):
– 01.00, 01.01, 02.00, 02.01, 03.00, 03.01
– 10.00, 10.01, 11.00, 11.01, ... BF.00, BF.01
● TCP port (passive): 5001, 102, 123, 20, 21, 25, 34962, 34963, 34964, 80
● UDP port (passive): 161, 34962, 34963, 34964

11.2.9

Communication with a programming device
A CPU can communicate with a STEP 7
programming device on a network.

Consider the following when setting up communications between a CPU and a programming
device:
● Configuration/Setup: Hardware configuration is required.
● No Ethernet switch is required for one-to-one communications; an Ethernet switch is
required for more than two devices in a network.

11.2.9.1

Establishing the hardware communications connection
The PROFINET interfaces establish the physical connections between a programming
device and a CPU. Since Auto-Cross-Over functionality is built into the CPU, either a
standard or crossover Ethernet cable can be used for the interface. An Ethernet switch is not
required to connect a programming device directly to a CPU.

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Follow the steps below to create the hardware connection between a programming device
and a CPU:
1. Install the CPU (Page 44).
2. Plug the Ethernet cable into the PROFINET port shown below.
3. Connect the Ethernet cable to the programming device.

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PROFINET port

An optional strain relief is available to strengthen the PROFINET connection.

11.2.9.2

Configuring the devices
If you have already created a project with a CPU, open your project in the TIA Portal.
If not, create a project and insert a CPU (Page 104) into the rack. In the project below, a
CPU is shown in the "Device View".

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11.2.9.3

Assigning Internet Protocol (IP) addresses

Assigning the IP addresses
In a PROFINET network, each device must also have an Internet Protocol (IP) address. This
address allows the device to deliver data on a more complex, routed network:
● If you have programming or other network devices that use an on-board adapter card
connected to your plant LAN or an Ethernet-to-USB adapter card connected to an
isolated network, you must assign IP addresses to them. Refer to "Assigning IP
addresses to programming and network devices" (Page 115) for more information.
● You can also assign an IP address to a CPU or network device online. This is particularly
useful in an initial device configuration. Refer to "Assigning an IP address to a CPU
online" (Page 115) for more information.
● After you have configured your CPU or network device in your project, you can configure
parameters for the PROFINET interface, to include its IP address. Refer to "Configuring
an IP address for a CPU in your project" (Page 117) for more information.

11.2.9.4

Testing your PROFINET network
After completing the configuration, you must download your project to the CPU. All IP
addresses are configured when you download the project.
The CPU "Download to device" function and its "Extended download to device" dialog can
show all accessible network devices and whether or not unique IP addresses have been
assigned to all devices. Refer to "Testing the PROFINET network" (Page 121) for more
information

11.2.10

HMI-to-PLC communication
The CPU supports PROFINET
communications connections to HMIs. The
following requirements must be considered
when setting up communications between
CPUs and HMIs:

Configuration/Setup:
● The PROFINET port of the CPU must be configured to connect with the HMI.
● The HMI must be setup and configured.
● The HMI configuration information is part of the CPU project and can be configured and
downloaded from within the project.
● No Ethernet switch is required for one-to-one communications; an Ethernet switch is
required for more than two devices in a network.

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Note
The rack-mounted CSM1277 4-port Ethernet switch can be used to connect your CPUs
and HMI devices. The PROFINET port on the CPU does not contain an Ethernet
switching device.
Supported functions:
● The HMI can read/write data to the CPU.
● Messages can be triggered, based upon information retrieved from the CPU.
● System diagnostics
Table 11- 28 Required steps in configuring communications between an HMI and a CPU
Step
1

Task
Establishing the hardware communications connection
A PROFINET interface establishes the physical connection between an HMI and a CPU. Since AutoCross-Over functionality is built into the CPU, you can use either a standard or crossover Ethernet cable
for the interface. An Ethernet switch is not required to connect an HMI and a CPU.
Refer to "Communication with a programming device: Establishing the hardware communications
connection" (Page 390) for more information.

Configuring the devices
Refer to "Communication with a programming device: Configuring the devices" (Page 391) for more
information.

Configuring the logical network connections between an HMI and a CPU
Refer to "HMI-to-PLC communication: Configuring the logical network connections between two devices"
(Page 393) for more information.

Configuring an IP address in your project
Use the same configuration process; however, you must configure IP addresses for the HMI and the CPU.
Refer to "Device configuration: Configuring an IP address for a CPU in your project" (Page 119) for more
information.

Testing the PROFINET network
You must download the configuration for each CPU and HMI device.
Refer to "Device configuration: Testing the PROFINET network" (Page 121) for more information.

11.2.10.1

Configuring logical network connections between two devices
After you configure the rack with the CPU, you are now ready to configure your network
connections.
In the Devices and Networks portal, use the "Network view" to create the network
connections between the devices in your project. First, click the "Connections" tab, and then
select the connection type with the dropdown, just to the right (for example, an ISO on TCP
connection).
To create a PROFINET connection, click the green (PROFINET) box on the first device, and
drag a line to the PROFINET box on the second device. Release the mouse button and your
PROFINET connection is joined.

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Refer to "Device Configuration: Creating a network connection" (Page 109) for more
information.

11.2.11

PLC-to-PLC communication
A CPU can communicate with another CPU on a
network by using the TSEND_C and TRCV_C
instructions.

Consider the following when setting up communications between two CPUs:
● Configuration/Setup: Hardware configuration is required.
● Supported functions: Reading/Writing data to a peer CPU
● No Ethernet switch is required for one-to-one communications; an Ethernet switch is
required for more than two devices in a network.
Table 11- 29 Required steps in configuring communications between two CPUs
Step
1

Task
Establishing the hardware communications connection
A PROFINET interface establishes the physical connection between two CPUs. Since Auto-Cross-Over
functionality is built into the CPU, you can use either a standard or crossover Ethernet cable for the
interface. An Ethernet switch is not required to connect the two CPUs.
Refer to "Communication with a programming device: Establishing the hardware communications
connection" (Page 390) for more information.

Configuring the devices
You must configure two CPUs in your project.
Refer to "Communication with a programming device: Configuring the devices" (Page 391) for more
information.

Configuring the logical network connections between two CPUs
Refer to "PLC-to-PLC communication: Configuring logical network connections between two devices"
(Page 395) for more information.

Configuring an IP address in your project
Use the same configuration process; however, you must configure IP addresses for two CPUs (for
example, PLC_1 and PLC_2).
Refer to "Device configuration: Configuring an IP address for a CPU in your project" (Page 119) for more
information.

Configuring transmit (send) and receive parameters
You must configure TSEND_C and TRCV_C instructions in both CPUs to enable communications between
them.
Refer to "Configuring communications between two CPUs: Configuring transmit (send) and receive
parameters" (Page 395) for more information.

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Step
6

Task
Testing the PROFINET network
You must download the configuration for each CPU.
Refer to "Device configuration: Testing the PROFINET network" (Page 121) for more information.

11.2.11.1

11.2.11.2

Configuring the Local/Partner connection path between two devices

Configuring General parameters
You specify the communication parameters in the "Properties" configuration dialog of the
communication instruction. This dialog appears near the bottom of the page whenever you
have selected any part of the instruction.
Refer to "Device configuration: Configuring the Local/Partner connection path (Page 110)"
for more information.
In the "Address Details" section of the Connection parameters dialog, you define the TSAPs
or ports to be used. The TSAP or port of a connection in the CPU is entered in the "Local
TSAP" field. The TSAP or port assigned for the connection in your partner CPU is entered
under the "Partner TSAP" field.

11.2.11.3

Configuring transmit (send) and receive parameters
Communication blocks (for example, TSEND_C and TRCV_C) are used to establish
connections between two CPUs. Before the CPUs can engage in PROFINET
communications, you must configure parameters for transmitting (or sending) messages and
receiving messages. These parameters dictate how communications operate when
messages are being transmitted to or received from a target device.

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Configuring the TSEND_C instruction transmit (send) parameters
TSEND_C instruction
The TSEND_C instruction (Page 366) creates a communications connection to a partner
station. The connection is set up, established, and automatically monitored until it is
commanded to disconnect by the instruction. The TSEND_C instruction combines the
functions of the TCON, TDISCON and TSEND instructions.
From the Device configuration in STEP 7, you can configure how a TSEND_C instruction
transmits data. To begin, you insert the instruction into the program from the
"Communications" folder in the "Instructions" task card. The TSEND_C instruction is
displayed, along with the Call options dialog where you assign a DB for storing the
parameters of the instruction.

You can assign tag memory locations to the inputs and outputs, as shown in the following
figure:

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Configuring General parameters
You specify the parameters in the Properties configuration dialog of the TSEND_C
instruction. This dialog appears near the bottom of the page whenever you have selected
any part of the TSEND_C instruction.

Configuring the TRCV_C instruction receive parameters
TRCV_C instruction
The TRCV_C instruction (Page 366) creates a communications connection to a partner
station. The connection is set up, established, and automatically monitored until it is
commanded to disconnect by the instruction. The TRCV_C instruction combines the
functions of the TCON, TDISCON, and TRCV instructions.
From the CPU configuration in STEP 7, you can configure how a TRCV_C instruction
receives data. To begin, insert the instruction into the program from the "Communications"
folder in the "Instructions" task card. The TRCV_C instruction is displayed, along with the
Call options dialog where you assign a DB for storing the parameters of the instruction.

You can assign tag memory locations to the inputs and outputs, as shown in the following
figure:

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Configuring the General parameters
You specify the parameters in the Properties configuration dialog of the TRCV_C instruction.
This dialog appears near the bottom of the page whenever you have selected any part of the
TRCV_C instruction.

11.2.12

Configuring a CPU and PROFINET IO device

Adding a PROFINET IO device
Use the hardware catalog to add PROFINET IO devices.
Note
STEP 7 Basic V10.5 or greater provides only a subset of the SIMATIC network devices in
the hardware catalog. To add a PROFINET IO device (such as ET200), you must use
STEP 7 Professional V11 or greater.
For example, expand the following containers in the hardware catalog to add an ET200S IO
device: Distributed I/O, ET200S, Interface modules, and PROFINET. You can then select the
interface module from the list of ET200S devices (sorted by part number) and add the
ET200S IO device.
Table 11- 30 Adding an ET200S IO device to the device configuration
Insert the IO device

Result

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You can now connect the PROFINET IO device to the CPU:
1. Right-click the "Not assigned" link on the device and select "Assign new IO controller"
from the context menu to display the "Select IO controller" dialog.
2. Select your S7-1200 CPU (in this example, "PLC_1") from the list of IO controllers in the
project.
3. Click "OK" to create the network connection.

Configuring logical network connections
After you configure the rack with the CPU, you are now ready to configure your network
connections.
In the Devices and Networks portal, use the "Network view" to create the network
connections between the devices in your project. To create a PROFINET connection, click
the green (PROFINET) box on the first device, and drag a line to the PROFINET box on the
second device. Release the mouse button and your PROFINET connection is joined.
Refer to "Device Configuration: Creating a network connection" (Page 109) for more
information.

Assigning CPUs and device names
Network connections between the devices also assign the PROFINET IO device to the CPU,
which is required for that CPU to control the device. To change this assignment, click the
PLC Name shown on the PROFINET IO device. A dialog box opens that allows the
PROFINET IO device to be disconnected from the current CPU and reassigned or left
unassigned, if desired.
The devices on your PROFINET network must have an assigned name before you can
connect with the CPU. Use the "Network view" to assign names to your PROFINET devices
if the devices have not already been assigned a name or if the name of the device is to be
changed. Right-click the PROFINET IO device, and select "Assign device name" to do this.
For each PROFINET IO device, you must assign the same name to that device in both the
STEP 7 project and, using the "Online & diagnostics" tool, to the PROFINET IO device
configuration memory (for example, an ET200 S interface module configuration memory). If
a name is missing or does not match in either location, the PROFINET IO data exchange
mode will not run. Refer to "Online and diagnostic tools: Assigning a name to a PROFINET
device online (Page 548)" for more information.

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Assigning the IP addresses
In a PROFINET network, each device must also have an Internet Protocol (IP) address. This
address allows the device to deliver data on a more complex, routed network:
● If you have programming or other network devices that use an on-board adapter card
connected to your plant LAN or an Ethernet-to-USB adapter card connected to an
isolated network, you must assign IP addresses to them. Refer to "Assigning IP
addresses to programming and network devices" (Page 115) for more information.
● You can also assign an IP address to a CPU or network device online. This is particularly
useful in an initial device configuration. Refer to "Assigning an IP address to a CPU
online" (Page 117) for more information.
● After you have configured your CPU or network device in your project, you can configure
parameters for the PROFINET interface, to include its IP address. Refer to "Configuring
an IP address for a CPU in your project" (Page 119) for more information.

Configuring the IO cycle time
A PROFINET IO device is supplied with new data from the CPU within an "IO cycle" time
period. The update time can be separately configured for each device and determines the
time interval in which data is transmitted from the CPU to and from the device.
STEP 7 calculates the "IO cycle" update time automatically in the default setting for each
device of the PROFINET network, taking into account the volume of data to be exchanged
and the number of devices assigned to this controller. If you do not want to have the update
time calculated automatically, you can change this setting.
You specify the "IO cycle" parameters in the "Properties" configuration dialog of the
PROFINET IO device. This dialog appears near the bottom of the page whenever you have
selected any part of the instruction.
In the "Device view" of the PROFINET IO device, click the PROFINET port. In the
"PROFINET Interface" dialog, access the "IO cycle" parameters with the following menu
selections:
● "Advanced options"
● "Realtime settings"
● "IO cycle"
Define the IO cycle "Update time" with the following selections:
● To have a suitable update time calculated automatically, select "Automatic".
● To set the update yourself, select "Can be set" and enter the required update time in ms.
● To ensure consistency between the send clock and the update time, activate the "Adapt
update time when send clock changes" option. This option ensures that the update time
is not set to less than the send clock.

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Table 11- 31 Configuring the ET200S PROFINET IO cycle time
ET200 S PROFINET IO device

ET200S PROFINET IO cycle dialog

① PROFINET port

11.2.13

Diagnostics

Diagnostic interrupt organization block (OB82)
If a module with diagnostic capability with diagnostic interrupt enabled detects a change in its
diagnostic status, it sends a diagnostic interrupt request to the CPU for the following
situations:
● A problem has been detected by this module (for example, a wire break) or a component
requires maintenance or both (incoming event).
● The problem has been corrected or no longer exists, and no further components require
maintenance (outgoing event).
If OB82 does not exist, these errors are written to the diagnostics buffer. The CPU does not
take any action or switch to STOP.
If OB82 does exist, the operating system can call OB82 in response to an incoming event.
You must create OB82, and this OB allows you to configure local error handling and a more
detailed reaction to incoming events.
If you are using a DPV1 capable CPU, you can obtain additional information on the interrupt
with the help of the RALRM instruction, which provides more specific information than the
start information of OB82.

Peripheral access alarms
These errors are written to the diagnostics buffer. The CPU does not take any action or
switch to STOP. Errors written to the diagnostics buffer include:
● Module faults
● Module mismatch
● Module missing
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IO access errors
These errors are written to the diagnostics buffer. The CPU does not take any action or
switch to STOP.

11.3

PROFIBUS
A PROFIBUS system uses a bus master to poll slave devices distributed in a multi-drop
fashion on an RS485 serial bus. A PROFIBUS slave is any peripheral device (I/O
transducer, valve, motor drive, or other measuring device) which processes information and
sends its output to the master. The slave forms a passive station on the network since it
does not have bus access rights, and can only acknowledge received messages, or send
response messages to the master upon request. All PROFIBUS slaves have the same
priority, and all network communication originates from the master.
A PROFIBUS master forms an "active station" on the network. PROFIBUS DP defines two
classes of masters. A class 1 master (normally a central programmable controller (PLC) or a
PC running special software) handles the normal communication or exchange of data with
the slaves assigned to it. A class 2 master (usually a configuration device, such as a laptop
or programming console used for commissioning, maintenance, or diagnostics purposes) is
a special device primarily used for commissioning slaves and for diagnostic purposes.
The S7-1200 is connected to a PROFIBUS network as a DP slave with the CM 1242-5
communication module. The CM 1242-5 (DP slave) module can be the communications
partner of DP V0/V1 masters. In the figure below, the S7-1200 is a DP slave to an S7-300
controller.

The S7-1200 is connected to a PROFIBUS network as a DP master with the CM 1243-5
communication module. The CM 1243-5 (DP master) module can be the communications
partner of DP V0/V1 slaves. In the figure below, the S7-1200 is a master controlling an
ET200S DP slave.

If a CM 1242-5 and a CM 1243-5 are installed together, an S7-1200 can perform as both a
slave of a higher-level DP master system and a master of a lower-level DP master system,
simultaneously.

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11.3 PROFIBUS

11.3.1

Communications modules PROFIBUS

11.3.1.1

Connecting to PROFIBUS

Connecting the S7-1200 to PROFIBUS DP
The S7-1200 can be connected to a PROFIBUS fieldbus system with the following
communications modules:
● CM 1242-5
Operates as DP slave
● CM 1243-5
Operates as DP master class 1
If a CM 1242-5 and a CM 1243-5 are installed together, an S7-1200 can perform the
following tasks simultaneously:
● Slave of a higher-level DP master system
and
● Master of a lower-level DP master system

11.3.1.2

Communications services of the PROFIBUS CMs

Bus protocol
The PROFIBUS CMs use the PROFIBUS DP-V1 protocol according to the following
standards:
● IEC 61158 (2004), type 3
● IEC 61784-1 (2007), CPF-3/1

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PROFIBUS communications partners of the S7-1200
The two PROFIBUS CMs allow the S7-1200 to exchange data with the following
communications partners.
● CM 1242-5
The CM 1242-5 (DP slave) can be the communications partner of the following DP V0/V1
masters:
– SIMATIC S7-1200, S7-300, S7-400
– DP master modules and the distributed IO SIMATIC ET200
– SIMATIC PC stations
– SIMATIC NET IE/PB Link
– Programmable controllers of various vendors
● CM 1243-5
The CM 1243-5 (DP master) can be the communications partner of the following DP
V0/V1 slaves:
– Drives and actuators from various vendors
– Sensors of various vendors
– S7-1200 CPU with PROFIBUS DP slave "CP 1242-5"
– S7-200 CPUs with PROFIBUS DP module EM 277
– DP slave modules and the distributed IO SIMATIC ET200
– CP 342-5
– S7-300/400 CPU with PROFIBUS interface
– S7-300/400 CPU with PROFIBUS CP

Types of communication with DP-V1
The following types of communication are available with DP-V1:
● Cyclic communication (CM 1242-5 and CM 1243-5)
Both PROFIBUS modules support cyclic communication for the transfer of process data
between DP slave and DP master.
Cyclic communication is handled by the operating system of the CPU. No software blocks
are required for this. The I/O data is read or written directly from/to the process image of
the CPU.
● Acyclic communication (CM 1243-5 only)
The DP master module also supports acyclic communication using software blocks:
– The "RALRM" instruction is available for interrupt handling.
– The "RDREC" and "WRREC" instructions are available for transferring configuration
and diagnostics data.

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Other communications services of the CM 1243-5
The CM 1243-5 DP master module supports the following additional communications
services:
● S7 communication
– PUT/GET services
The DP master functions as a client and server for queries from other S7 controllers or
PCs via PROFIBUS.
– PG/OP communication
The PG functions allow the downloading of configuration data and user programs from
a PG and the transfer of diagnostics data to a PG.
Possible communications partners for OP communication are HMI panels, SIMATIC
panel PCs with WinCC flexible or SCADA systems that support S7 communication.

11.3.1.3

Other properties of the PROFIBUS CMs

Configuration and module replacement
You configure the modules, networks and connections in STEP 7 as of version V11.0.
If you want to configure the module in a third-party system, there is a GSD file available for
the CM 1242-5 (DP slave) on the CD that ships with the module and on Siemens Automation
Customer Support pages on the Internet.
The configuration data of the PROFIBUS CMs is stored on the local CPU. This allows simple
replacement of these communications modules when necessary.
You can configure a maximum of three PROFIBUS CMs per station, of which only one may
be a DP master.

Electrical connections
● Power supply
– The CM 1242-5 is supplied with power via the backplane bus of the SIMATIC station.
– The CM 1243-5 has a separate connector for the 24 VDC power supply.
● PROFIBUS
The RS-485 interface of the PROFIBUS connector is a 9-pin D-sub female connector.
You also have the option of connecting to optical PROFIBUS networks via an Optical Bus
Terminal OBT or an Optical Link Module OLM.

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Further information
You will find detailed information on the PROFIBUS CMs in the manuals of the devices. You
will find these on the Internet on the pages of Siemens Industrial Automation Customer
Support under the following entry IDs:
● CM 1242-5:
42330605 (http://support.automation.siemens.com/WW/view/en/42330605)
● CM 1243-5:
42330529 (http://support.automation.siemens.com/WW/view/en/42330529)

11.3.1.4

Configuration examples for PROFIBUS
Below, you will find examples of configurations in which the CM 1242-5 is used as a
PROFIBUS slave and the CM 1243-5 is used as a PROFIBUS master.
PG/PC/IPC

SIMATIC S7-300

Operator control &
monitoring

PROFIBUS

SIMATIC S7-1200
with CM 1242-5

OLM

PROFINET/
Industrial Ethernet
PROFIBUS
(LWL)

Operator control &
monitoring

Figure 11-1

SIMATIC S7-1200
with CM 1242-5

Configuration example with a CM 1242-5 as PROFIBUS slave

SIMATIC S7-1200
with CM 1243-5

Operator control &
monitoring

PROFIBUS

PG/PC/IPC

Figure 11-2

SINAMICS

ET 200S

Configuration example with a CM 1243-5 as PROFIBUS master

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11.3.2

Configuring a DP master and slave device

11.3.2.1

Adding the CM 1243-5 (DP master) module and a DP slave
Use the hardware catalog to add PROFIBUS modules to the CPU. These modules are
connected to the left side of the CPU. To insert a module into the hardware configuration,
select the module in the hardware catalog and either double-click or drag the module to the
highlighted slot.

Table 11- 32 Adding a PROFIBUS CM 1243-5 (DP master) module to the device configuration
Module

Select the module

Insert the module

Result

CM 1243-5
(DP
master)

Use the hardware catalog to add DP slaves as well. For example, to add an ET200 S DP
slave, in the Hardware Catalog, expand the following containers:
● Distributed I/O
● ET200 S
● Interface modules
● PROFIBUS
Next, select "6ES7 151-1BA02-0AB0" (IM151-1 HF) from the list of part numbers, and add
the ET200 S DP slave as shown in the figure below.
Table 11- 33 Adding an ET200 S DP slave to the device configuration
Insert the DP slave

Result

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11.3 PROFIBUS

11.3.2.2

Configuring logical network connections between two PROFIBUS devices
After you configure the CM 1243-5 (DP master) module, you are now ready to configure your
network connections.
In the Devices and Networks portal, use the "Network view" to create the network
connections between the devices in your project. To create the PROFIBUS connection,
select the purple (PROFIBUS) box on the first device. Drag a line to the PROFIBUS box on
the second device. Release the mouse button and your PROFIBUS connection is joined.
Refer to "Device Configuration: Creating a network connection" (Page 109) for more
information.

11.3.2.3

Assigning PROFIBUS addresses to the CM 1243-5 module and DP slave

Configuring the PROFIBUS interface
After you configure logical network connections between two PROFIBUS devices, you can
configure parameters for the PROFIBUS interfaces. To do so, click the purple PROFIBUS
box on the CM 1243-5 module, and the "Properties" tab in the inspector window displays the
PROFIBUS interface. The DP slave PROFIBUS interface is configured in the same manner.
Table 11- 34 Configuring the CM 1243-5 (DP master) module and ET200 S DP slave PROFIBUS
interfaces
CM 1243-5 (DP master) module

ET200 S DP slave

① PROFIBUS port
Assigning the PROFIBUS address
In a PROFIBUS network, each device is assigned a PROFIBUS address. This address can
range from 0 through 127, with the following exceptions:
● Address 0: Reserved for network configuration and/or programming tools attached to the
bus
● Address 1: Reserved by Siemens for the first master
● Address 126: Reserved for devices from the factory that do not have a switch setting and
must be re-addressed through the network
● Address 127: Reserved for broadcast messages to all devices on the network and may
not be assigned to operational devices

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Thus, the addresses that may be used for PROFIBUS operational devices are 2 through
125.
In the Properties window, select the "PROFIBUS address" configuration entry. STEP 7
displays the PROFIBUS address configuration dialog, which is used to assign the
PROFIBUS address of the device.

Table 11- 35 Parameters for the PROFIBUS address
Parameter
Subnet

Parameters

Description
Name of the Subnet to which the device is connected. Click the "Add new subnet" button to create a
new subnet. "Not connected" is the default. Two connection types are possible:


The "Not connected" default provides a local connection.



A subnet is required when your network has two or more devices.

Address

Assigned PROFIBUS address for the device

Highest address

The highest PROFIBUS address is based on the active stations on the
PROFIBUS (for example, DP master). Passive DP slaves independently
have PROFIBUS addresses from 1 to 125 even if the highest PROFIBUS
address is set to 15, for example. The highest PROFIBUS address is
relevant for token forwarding (forwarding of the send rights), and the token
is only forwarded to active stations. Specifying the highest PROFIBUS
address optimizes the bus.

Transmission rate

Transmission rate of the configured PROFIBUS network: The PROFIBUS
transmission rates range from 9.6 Kbits/sec to 12 Mbits/sec. The
transmission rate setting depends on the properties of the PROFIBUS
nodes being used. The transmission rate should not be greater than the
rate supported by the slowest node.
The transmission rate is normally set for the master on the PROFIBUS
network, with all DP slaves automatically using that same transmission rate
(auto-baud).

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11.4 Distributed I/O

11.4

Distributed I/O

11.4.1

Distributed I/O Instructions
The following distributed I/O instructions (Page 234) can be used with either PROFINET or
PROFIBUS:
● RDREC instruction (Page 234): You can read a data record with the number INDEX from
a component.
● WRREC instruction (Page 234): You can transfer a data record with the number INDEX
to a DP slave or PROFINET IO device component defined by ID.
● RALRM instruction (Page 237): You can receive an interrupt with all corresponding
information from a DP slave or PROFINET IO device component and supply this
information to its output parameters.
● DPRD_DAT instruction (Page 242): The CPU supports up to 64 bytes of consistent data.
You must read consistent data areas greater than 64 bytes from a DP standard slave or
PROFINET IO device with the DPRD_DAT instruction.
● DPWR_DAT instruction (Page 242): The CPU supports up to 64 bytes of consistent data.
You must write consistent data areas greater than 64 bytes to a DP standard slave or
PROFINET IO device with the DPWR_DAT instruction.
For PROFIBUS, you can use the DPNRM_DG instruction (Page 244) to read the current
diagnostic data of a DP slave in the format specified by EN 50 170 Volume 2, PROFIBUS.

11.4.2

Diagnostic instructions
The following diagnostic instructions can be used with either PROFINET or PROFIBUS:
● GET_DIAG instruction (Page 259): You can read the diagnostic information from a
specified device.
● DeviceStates instruction (Page 257): You can retrieve the operational states for a
distributed I/O device within an I/O subsystem.
● ModuleStates instruction (Page 258): You can retrieve the operational states for the
modules in a distributed I/O device.
● LED instruction (Page 256): You can read the state of the LEDs for a distributed I/O
device.

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11.4 Distributed I/O

11.4.3

Diagnostic events for distributed I/O
Note
In order for the PROFINET IO system to start after a download or power cycle the hardware
configuration must match the actual hardware in the system.
Variances in the configuration are allowed if the CPU was configured to allow either any
substitue or an acceptable substitute modules (Page 107).
If a module is missing or has been removed from the station, the CPU will not go to RUN
mode until the hardware configuration error is resolved.
As shown in the following table, the CPU supports diagnostics that can be configured for the
components of the distributed I/O system. Each of these errors generates a log entry in the
diagnostic buffer.

Table 11- 36 Handling of diagnostic events for PROFINET and PROFIBUS
Type of error

Diagnostic information for
the station?

Entry in the diagnostic
buffer?

CPU operating mode

Diagnostic error

Yes

Stays in RUN mode

Rack or station failure

Yes

Stays in RUN mode

I/O access error

Yes

Stays in RUN mode

Peripheral access error

Yes

Stays in RUN mode

Pull / plug event

Yes

Stays in RUN mode

Use the GET_DIAG instruction (Page 259) for each station to obtain the diagnostic
information. This will allow you to programmatically handle the errors encountered on the
device and if desired take the CPU to STOP mode. This method requires you to specify the
hardware device from which to read the status information.
The GET_DIAG instruction uses the "L address" (LADDR) of the station to obtain the health
of the entire station. This L Address can be found within the Network Configuration view and
by selecting the entire station rack (entire gray area), the L Address is shown in the
Properties Tab of the station. You can find the LADDR for each individual module either in
the properties for the module (in the device configuration) or in the default tag table for the
CPU.

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11.5 S7 communication

11.5

S7 communication

11.5.1

GET and PUT instructions
You can use the GET and PUT instructions to communicate with S7 CPUs through
PROFINET and PROFIBUS connections.
● Accessing data in an S7-300/400 CPU: An S7-1200 CPU can use either absolute
addresses or symbolic names to address variables of an S7-300/400 CPU. Data types of
the remote communication partner that are not supported by the calling S7 1200-CPU
may only be accessed as a byte array. For example, S7-300 data type DT is accessed as
an array of 8 bytes.
● Accessing data in a standard DB: An S7-1200 CPU can use either absolute addresses or
symbolic names to address DB variables in a standard DB of a remote S7 CPU.
● Accessing data in an optimized DB; An S7-1200 CPU can only use symbolic names to
address DB variables in an optimized DB of a remote S7 CPU. Only variables of the first
nesting level are supported. This includes variables which are declared in an optimized
global DB at the DB level. Components of optimized DB structures or elements of arrays
cannot be addressed.

Table 11- 37 GET and PUT instructions
LAD / FBD

Description
Use the GET instruction to read data from a remote S7 CPU. The remote CPU can be in
either RUN or STOP mode.
STEP 7 automatically creates the DB when you insert the instruction.

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11.5 S7 communication

LAD / FBD

Description
Use the PUT instruction to write data to a remote S7 CPU. The remote CPU can be in
either RUN or STOP mode.
STEP 7 automatically creates the DB when you insert the instruction.

Table 11- 38 Data types for the parameters
Parameter and type

Data type

Description

REQ

Input

Bool

A low to high (positive edge) signal starts the operation.

Input

CONN_PRG
(Word)

Connection identifier

NDR (GET)

Output

Bool

New Data Ready:

DONE (PUT)

Output

Bool

ERROR

Output

Bool

STATUS

Output

Word



0: request has not yet started or is still running



1: task was completed successfully

DONE:


0: request has not yet started or is still running



1: task was completed successfully



ERROR=0
STATUS value:



–

0000H: neither warning nor error

–

<> 0000H: Warning, STATUS supplies detailed information

ERROR=1
There is an error. STATUS supplies detailed information about
the nature of the error.

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11.5 S7 communication

Parameter and type

Data type

Description

ADDR_1

InOut

Remote

ADDR_2

InOut

Remote

Pointer to the memory areas in the remote CPU that stores the
data to be read (GET) or that is sent (PUT).

ADDR_3

InOut

Remote

ADDR_4

InOut

Remote

RD_1 (GET)
SD_1 (PUT)

InOut

Variant

Pointer to the memory areas in the local CPU that stores the data
to be read (GET) or sent (PUT).

RD_2 (GET)
SD_2 (PUT)

InOut

Variant

Data types allowed: Bool (only a single bit allowed), Byte, Char,
Word, Int, DWord, DInt, or Real.

RD_3 (GET)
SD_3 (PUT)

InOut

Variant

Note: If the pointer accesses a DB, you must specify the absolute
address, such as:

RD_4 (GET)
SD_4 (PUT)

InOut

Variant

P# DB10.DBX5.0 Byte 10

You must ensure that the length and data types for the ADDR_x (remote CPU) and RD_x or
SD_x (local CPU) parameters match.
On the rising edge of the REQ parameter, the read operation (GET) or write operation (PUT)
loads the ID, ADDR_1, and RD_1 (GET) or SD_1 (PUT) parameters.
● For GET: The remote CPU returns the requested data to the receive areas (RD_x),
starting with the next scan. When the read operation has completed without error, the
NDR parameter is set to 1. A new operation can only be started only after the previous
operation has completed.
● For PUT: The local CPU starts sending the data (SD_x) to the memory location (ADDR_x)
in the remote CPU. When the write operation has completed without error, the remote
CPU returns an execution acknowledgement. The DONE parameter of the PUT
instruction is then set to 1. A new write operation can only be started after the previous
operation has completed.
Note
To ensure data consistency, always evaluate when the operation has been completed
(NDR = 1 for GET, or DONE = 1 for PUT) before accessing the data or initiating another
read or write operation.
The ERROR and STATUS parameters provide information about the status of the read
(GET) or write (PUT) operation.
Table 11- 39 Error information
ERROR

STATUS
(decimal)

Description



New job cannot take effect since previous job is not yet completed.



The job is now being processed in a priority class having lower priority.

Communication has started. The job is being processed.

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11.5 S7 communication

ERROR

STATUS
(decimal)

Description

Communications problems, such as:


Connection description not loaded (local or remote)



Connection interrupted (for example: cable, CPU is turned off, or CM/CB/CP is in
STOP mode)



Connection to partner not yet established

Negative acknowledgement from the partner device. The task cannot be executed.

Errors in the send area pointers (RD_x for GET, or SD_x for PUT) involving the data
length or the data type.

Access error on the partner CPU

Access to the local user memory not possible (for example, attempting to access a
deleted DB)

When the SFB was called:



An instance DB was specified that does not belong to GET or PUT



No instance DB was specified, but rather a shared DB



No instance DB found (loading a new instance DB)



Exceeded the maximum number of parallel jobs/instances

 The instances were overloaded at CPU-RUN
This status is possible for first execution of the GET or PUT instruction
1

11.5.2

There is no corresponding GET or PUT instruction in the CPU.

Creating an S7 connection
The connection type that you select creates a communication connection to a partner
station. The connection is set up, established, and automatically monitored.
In the Devices and Networks portal, use the "Network view" to create the network
connections between the devices in your project. First, click the "Connections" tab, and then
select the connection type with the dropdown, just to the right (for example, an S7
connection). Click the green (PROFINET) box on the first device, and drag a line to the
PROFINET box on the second device. Release the mouse button and your PROFINET
connection is joined.
Refer to "Creating a network connection" (Page 109) for more information.

Click the "Highlighted: Connection" button to access the "Properties" configuration dialog of
the communication instruction.

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11.6 Telecontrol and TeleService with the CP 1242-7

11.5.3

Configuring the Local/Partner connection path between two devices

11.6

Telecontrol and TeleService with the CP 1242-7

11.6.1

Connection to a GSM network

IP-based WAN communication via GPRS
Using the CP 1242-7 communications processor, the S7-1200 can be connected to GSM
networks. The CP 1242-7 allows WAN communication from remote stations with a control
center and inter-station communication.
Inter-station communication is possible only via a GSM network. For communication
between a remote station and a control room, the control center must have a PC with
Internet access.
The CP 1242-7 supports the following services for communication via the GSM network:
● GPRS (General Packet Radio Service)
The packet-oriented service for data transmission "GPRS" is handled via the GSM
network.
● SMS (Short Message Service)
The CP 1242-7 can receive and send SMS messages. The communications partner can
be a mobile phone or an S7-1200.
The CP 1242-7 is suitable for use in industry worldwide and supports the following frequency
bands:
● 850 MHz
● 900 MHz
● 1 800 MHz
● 1 900 MHz

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11.6 Telecontrol and TeleService with the CP 1242-7

Requirements
The equipment used in the stations or the control center depends on the particular
application.
● For communication with or via a central control room, the control center requires a PC
with Internet access.
● Apart from the station equipment, a remote S7-1200 station with a CP 1242-7 must meet
the following requirements to be able to communicate via the GSM network:
– A contract with a suitable GSM network provider
If GPRS is used, the contract must allow the use of the GPRS service.
If there is to be direct communication between stations only via the GSM network, the
GSM network provider must assign a fixed IP address to the CPs. In this case,
communication between stations is not via the control center.
– The SIM card belonging to the contract
The SIM card is inserted in the CP 1242-7.
– Local availability of a GSM network in the range of the station

11.6.2

Applications of the CP 1242-7
The CP 1242-7 can be used for the following applications:

Telecontrol applications
● Sending messages by SMS
Via the CP 1242-7, the CPU of a remote S7-1200 station can receive SMS messages
from the GSM network or send messages by SMS to a configured mobile phone or an
S7-1200.
● Communication with a control center
Remote S7-1200 stations communicate via the GSM network and the Internet with a
telecontrol server in the master station. For data transfer using GPRS, the
"TELECONTROL SERVER BASIC" application is installed on the telecontrol server in the
master station. The telecontrol server communicates with a higher-level central control
system using the integrated OPC server function.
● Inter-station communication between S7-1200 stations via a GSM network
Inter-station communication between remote stations with a CP 1242-7 can be handled in
two different ways:
– Indirect communication via a master station
In this configuration, a permanent secure connection between S7-1200 stations that
communicate with each other and the telecontrol server is established in the master
station. Communication between the stations is via the telecontrol server. The
CP 1242-7 operates in "Telecontrol" mode.

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11.6 Telecontrol and TeleService with the CP 1242-7
– Direct communication between the stations
For direct communication between stations without the detour via the master station,
SIM cards with a fixed IP address are used that allow the stations to address each
other directly. The possible communications services and security functions (for
example VPN) depend on what is offered by the network provider. The CP 1242-7
operates in "GPRS direkt" mode.

TeleService via GPRS
A TeleService connection can be established between an engineering station with STEP 7
and a remote S7-1200 station with a CP 1242-7 via the GSM network and the Internet. The
connection runs from the engineering station via a telecontrol server or a TeleService
gateway that acts as an intermediary forwarding frames and establishing the authorization.
These PCs use the functions of the "TELECONTROL SERVER BASIC" application.
You can use the TeleService connection for the following purposes:
● Downloading configuration or program data from the STEP 7 project to the station
● Querying diagnostics data on the station

11.6.3

Other properties of the CP

Other services and functions of the CP 1242-7
● Time-of-day synchronization of the CP via the Internet
You can set the time on the CP as follows:
– In "Telecontrol" mode, the time of day is transferred by the telecontrol server. The CP
uses this to set its time.
– In "GPRS direct" mode, the CP can request the time using SNTP.
To synchronize the CPU time, you can read out the current time from the CP using a
block.
● Interim buffering of messages to be sent if there are connection problems
● Logging the volume of data
The volumes of data transferred are logged and can be evaluated for specific purposes.

Configuration and module replacement
You configure the CP 1242-7 in STEP 7 as of version V11.0. For process data transfer using
GPRS, use the telecontrol communications instructions in the user program of the station.
The configuration data of the CP 1242-7 is stored on the local CPU. This allows simple
replacement of the CP when necessary.
You can insert up to three modules of the CP 1242-7 type per S7-1200. This, for example,
allows redundant communications paths to be established.

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11.6 Telecontrol and TeleService with the CP 1242-7

Electrical connections
● Power supply of the CP 1242-7
The CP a separate connector for the 24 V DC power supply.
● Wireless interface for the GSM network
An extra antenna is required for GSM communication. This is connected via the SMA
socket of the CP.

Further information
The CP 1242-7 manual contains detailed information. You will find this on the Internet on the
pages of Siemens Industrial Automation Customer Support under the following entry ID:
42330276 (http://support.automation.siemens.com/WW/view/en/42330276)

11.6.4

Accessories

The ANT794-4MR GSM/GPRS antenna
The following antennas are available for use in GSM/GPRS networks and can be installed
both indoors and outdoors:
● Quadband antenna ANT794-4MR

Figure 11-3

Short name
ANT794-4MR

ANT794-4MR GSM/GPRS antenna

Order no.
6NH9 860-1AA00

Explanation
Quadband antenna (900, 1800/1900 MHz, UMTS);
weatherproof for indoor and outdoor areas; 5 m
connecting cable connected permanently to the
antenna; SMA connector, including installation
bracket, screws, wall plugs

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11.6 Telecontrol and TeleService with the CP 1242-7
● Flat antenna ANT794-3M

Figure 11-4

Flat antenna ANT794-3M

Short name

Order no.

ANT794-3M

Explanation

6NH9 870-1AA00

Flat antenna (900, 1800/1900 MHz); weatherproof
for indoor and outdoor areas; 1.2 m connecting cable
connected permanently to the antenna; SMA
connector, including adhesive pad, screws mounting
possible

The antennas must be ordered separately.

Further information
You will find detailed information in the device manual. You will find this on the Internet on
the pages of Siemens Industrial Automation Customer Support under the following entry ID:
23119005 (http://support.automation.siemens.com/WW/view/en/23119005)

11.6.5

Configuration examples for telecontrol
Below, you will find several configuration examples for stations with a CP 1242-7.

Sending messages by SMS

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11.6 Telecontrol and TeleService with the CP 1242-7
A SIMATIC S7-1200 with a CP 1242-7 can send messages by SMS to a configured mobile
phone or a configured S7-1200 station.

Telecontrol by a control center
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In telecontrol applications, SIMATIC S7-1200 stations with a CP 1242-7 communicate with a
control center via the GSM network and the Internet. The TELECONTROL SERVER BASIC
application is installed on the telecontrol server in the master station. This results in the
following use cases:
● Telecontrol communication between station and control center
In this use case, data from the field is sent by the stations to the telecontrol server in the
master station via the GSM network and Internet. The telecontrol server is used to control
and monitor remote stations.
● Communication between a station and a control center PC with OPC client
As in the first case, the stations communicate with the telecontrol server. Using the OPC
server of TELECONTROL SERVER BASIC, the telecontrol server exchanges data with a
master station PC. The control center PC could, for example, have WinCC and an
integrated OPC client installed on it.
● Inter-station communication via a control center
To allow inter-station communication, the telecontrol server forwards the messages of the
sending station to the receiving station.

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11.6 Telecontrol and TeleService with the CP 1242-7

Direct communication between stations
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In this configuration, two SIMATIC S7-1200 stations communicate directly with each other
using the CP 1242-7 via the GSM network. Each CP 1242-7 has a fixed IP address. The
relevant service of the GSM network provider must allow this.

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11.6 Telecontrol and TeleService with the CP 1242-7
In TeleService via GPRS, an engineering station on which STEP 7 is installed communicates
via the GSM network and the Internet with a SIMATIC S7-1200 station with a CP 1242-7.
The connection runs via a telecontrol server that serves as an intermediary and is connected
to the Internet.

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11.6 Telecontrol and TeleService with the CP 1242-7

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12.1

Using the RS232 and RS485 communication interfaces
Two communication modules (CMs) and one communication board (CB) provide the
interface for PtP communications:
● CM 1241 RS232 (Page 650)
● CM 1241 RS485 (Page 648)
● CB 1241 RS485 (Page 646)
You can connect up to three CMs (of any type) plus a CB for a total of four communication
interfaces. Install the CM to the left of the CPU or another CM. Install the CB on the front of
the CPU. Refer to the "Installation" chapter (Page 48) for detailed instructions on module
installation and removal.
The RS232 and RS485 communication interfaces have the following characteristics:
● Have an isolated port
● Support Point-to-Point protocols
● Are configured and programmed through extended instructions and library functions
● Display transmit and receive activity by means of LEDs
● Display a diagnostic LED (CMs only)
● Are powered by the CPU: No external power connection is needed.
Refer to the technical specifications for communication interfaces (Page 640).

LED indicators
The communication modules have three LED indicators:
● Diagnostic LED (DIAG): This LED flashes red until it is addressed by the CPU. After the
CPU powers up, it checks for a CB or CMs and addresses them. The diagnostic LED
begins to flash green. This means that the CPU has addressed the CM or CB, but has
not yet provided the configuration to it. The CPU downloads the configuration to the
configured CMs and CB when the program is downloaded to the CPU. After a download
to the CPU, the diagnostic LED on the communication module or communication board
should be a steady green.
● Transmit LED (Tx): The transmit LED illuminates when data is being transmitted out the
communication port.
● Receive LED (Rx): This LED illuminates when data is being received by the
communication port.
The communication board provides transmit (TxD) and receive (RxD) LEDs. It has no
diagnostic LED.

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12.2 Biasing and terminating an RS485 network connector

12.2

Biasing and terminating an RS485 network connector
Siemens provides an RS485 network connector (Page 660) that you can use to easily
connect multiple devices to an RS485 network. The connector has two sets of terminals that
allow you to attach the incoming and outgoing network cables. The connector also includes
switches for selectively biasing and terminating the network.
Note
You terminate and bias only the two ends of the RS485 network. The devices in between the
two end devices are not terminated or biased.

཰

ཱ

ABAB

཰

2II
ABAB

2Q
A B AB

ི

①
②

End (terminating) devices: Switch position = ON (to terminate and bias the connector)

③

Bare cable shielding: Approximately 12 mm must contact the metal guides of all locations.

Other (non-terminating) devices on the network: Switch position = OFF (no termination or bias
for the connector)

Table 12- 1

Termination and bias for the RS485 connector

Terminating device (bias ON)

Non-terminating device (bias OFF)
6

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ཱ

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3

཰

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① A = TxD/RxD - (Green wire / Pin 8)
② B = TxD/RxD + (Red wire / Pin 3)
The CB 1241 provides internal resistors for terminating and biasing the network. To
terminate and bias the connection, connect TRA to TA and connect TRB to TB to include the
internal resistors to the circuit. CB 1241 does not have a 9-pin connector. The following table
shows the connections to a 9-pin connector on the communications partner.

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12.3 Point-to-Point (PtP) communication
Table 12- 2

Termination and bias for the CB 1241

Terminating device (bias ON)

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ི

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75$

Non-terminating device (bias OFF)

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$
%

ཱ

ི

0
7$
75$

75%

① Connect M to the cable shield
② A = TxD/RxD - (Green wire / Pin 8)
③ B = TxD/RxD + (Red wire / Pin 3)

12.3

Point-to-Point (PtP) communication
The CPU supports the following Point-to-Point communication (PtP) for character-based
serial protocols. PtP provides maximum freedom and flexibility, but requires extensive
implementation in the user program.
● PtP (Page 427)
● USS (Page 460)
● Modbus (Page 474)
PtP enables a wide variety of possibilities:
 The ability to send information directly to an external
device such as a printer
 The ability to receive information from other devices
such as barcode readers, RFID readers, third-party
camera or vision systems, and many other types of
devices
 The ability to exchange information, sending and
receiving data, with other devices such as GPS
devices, third-party camera or vision systems, radio
modems, and many more
PtP communication is serial communication that uses standard UARTs to support a variety
of baud rates and parity options. The RS232 and RS485 communication modules and the
RS485 communication board provide the electrical interfaces for performing the PtP
communications.

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12.3 Point-to-Point (PtP) communication

12.3.1

Point-to-Point instructions

12.3.1.1

Common parameters for Point-to-Point instructions

Table 12- 3

Common input parameters for the PTP instructions

Parameter

Description

REQ

Many of the PtP instructions use the REQ input to initiate the operation on a low to high
transition. The REQ input must be high (TRUE) for one execution of an instruction, but the REQ
input can remain TRUE for as long as desired. The instruction does not initiate another operation
until it has been called with the REQ input FALSE so that the instruction can reset the history
state of the REQ input. This is required so that the instruction can detect the low to high transition
to initiate the next operation.
When you place a PtP instruction in your program, STEP 7 prompts you to identify the instance
DB. Use a unique DB for each PtP instruction call. This ensures that each instruction properly
handles inputs such as REQ.

PORT

A port address is assigned during communication device configuration. After configuration, a
default port symbolic name can be selected from the parameter assistant drop-list. The assigned
CM or CB port value is the device configuration property "hardware identifier". The port symbolic
name is assigned in the "Constants" tab of the PLC tag table.

Bit time resolution

Several parameters are specified in a number of bit times at the configured baud rate. Specifying
the parameter in bit times allows the parameter to be independent of baud rate. All parameters
that are in units of bit times can be specified to a maximum number of 65535. However, the
maximum amount of time that a CM or CB can measure is eight seconds.

The DONE, NDR, ERROR, and STATUS output parameters of the PtP instructions provide
execution completion status for the PtP operations.
Table 12- 4

DONE, NDR, ERROR, and STATUS output parameters

Parameter

Data type

Default

Description

DONE

Bool

FALSE

Set TRUE for one execution to indicate that the last request
completed without errors; otherwise, FALSE.

NDR

Bool

FALSE

Set TRUE for one execution to indicate that the requested action
has completed without error and that the new data has been
received; otherwise, FALSE.

ERROR

Bool

FALSE

Set TRUE for one execution to indicate that the last request
completed with errors, with the applicable error code in STATUS;
otherwise, FALSE.

STATUS

Word

Result status:


If the DONE or NDR bit is set, then STATUS is set to 0 or to an
informational code.



If the ERROR bit is set, then STATUS is set to an error code.

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Note
The DONE, NDR, and ERROR parameters are set for one execution only. Your program
logic must save temporary output state values in data latches, so you can detect state
changes in subsequent program scans.

Table 12- 5

Common condition codes

STATUS (W#16#....)

Description

0000

No error

7000

Function is not busy

7001

Function is busy with the first call.

7002

Function is busy with subsequent calls (polls after the first call).

8x3A

Illegal pointer in parameter x

8070

All internal instance memory in use, too many concurrent instructions in progress

8080

Port number is illegal.

8081

Timeout, module error, or other internal error

8082

Parameterization failed because parameterization is in progress in background.

8083

Buffer overflow:
The CM or CB returned a received message with a length greater than the length parameter
allowed.

Table 12- 6

8090

Internal error: Wrong message length, wrong sub-module, or illegal message
Contact customer support.

8091

Internal error: Wrong version in parameterization message
Contact customer support.

8092

Internal error: Wrong record length in parameterization message
Contact customer support.

Common error classes

Class description

Error classes

Description

Port configuration

80Ax

Used to define common port configuration errors

Transmit configuration

80Bx

Used to define common transmit configuration errors

Receive configuration

80Cx

Used to define common receive configuration errors

Transmission runtime

80Dx

Used to define common transmission runtime errors

Reception runtime

80Ex

Used to define common reception runtime errors

Signal handling

80Fx

Used to define common errors associated with all signal
handling

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12.3.1.2
Table 12- 7

PORT_CFG instruction
PORT_CFG (Port Configuration) instruction

LAD / FBD

Description
PORT_CFG allows you to change port parameters such as baud rate from your program.
You can set up the initial static configuration of the port in the device configuration
properties, or just use the default values. You can execute the PORT_CFG instruction in
your program to change the configuration.

STEP 7 automatically creates the DB when you insert the instruction.

The PORT_CFG configuration changes are not permanently stored in the CPU. The
parameters configured in the device configuration are restored when the CPU transitions
from RUN to STOP mode and after a power cycle. See Configuring the communication ports
(Page 444) and Managing flow control (Page 445) for more information.
Table 12- 8

Data types for the parameters

Parameter and type

Data type

Description

REQ

Bool

Activate the configuration change on rising edge of this input. (Default value:
False)

PORT

After you install and configure a CM or CB communication device, the port
identifier appears in the parameter helper drop-list available at the PORT
box connection. The assigned CM or CB port value is the device
configuration property "hardware identifier". The port symbolic name is
assigned in the "System constants" tab of the PLC tag table. (Default value:
0)

PROTOCOL

UInt

0 - Point-to-Point communication protocol (Default value)
1..n - future definition for specific protocols

BAUD

UInt

Port baud rate (Default value: 0):
1 = 300 baud, 2 = 600 baud, 3 = 1200 baud, 4 = 2400 baud, 5 = 4800 baud,
6 = 9600 baud, 7 = 19200 baud, 8 = 38400 baud, 9 = 57600 baud,
10 = 76800 baud, 11 = 115200 baud

PARITY

UInt

Port parity (Default value: 0):
1 = No parity, 2 = Even parity, 3 = Odd parity, 4 = Mark parity,
5 = Space parity

DATABITS

UInt

Bits per character (Default value:):
1 = 8 data bits, 2 = 7 data bits

STOPBITS

UInt

Stop bits (Default value: 0):
1 = 1 stop bit, 2 = 2 stop bits

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Parameter and type

Data type

Description

FLOWCTRL

UInt

Flow control (Default value: 0):
1 = No flow control, 2 = XON/XOFF, 3 = Hardware RTS always ON,
4 = Hardware RTS switched

XONCHAR

Char

Specifies the character that is used as the XON character. This is typically a
DC1 character (11H). This parameter is only evaluated if flow control is
enabled. (Default value: 0)

XOFFCHAR

Char

Specifies the character that is used as the XOFF character. This is typically
a DC3 character (13H). This parameter is only evaluated if flow control is
enabled. (Default value: 0)

XWAITIME

UInt

Specifies how long to wait for a XON character after receiving a XOFF
character, or how long to wait for the CTS signal after enabling RTS (0 to
65535 ms). This parameter is only evaluated if flow control is enabled.
(Default value: 2000)

DONE

OUT

Bool

TRUE for one execution after the last request was completed with no error

ERROR

OUT

Bool

TRUE for one execution after the last request was completed with an error

STATUS

OUT

Word

Execution condition code (Default value: 0)

Table 12- 9

Condition codes

STATUS (W#16#....)

Description

80A0

Specific protocol does not exist.

80A1

Specific baud rate does not exist.

80A2

Specific parity option does not exist.

80A3

Specific number of data bits does not exist.

80A4

Specific number of stop bits does not exist.

80A5

Specific type of flow control does not exist.

80A6

Wait time is 0 and flow control enabled

80A7

XON and XOFF are illegal values (for example, the same value)

12.3.1.3

SEND_CFG instruction

Table 12- 10 SEND_CFG (Send Configuration) instruction
LAD / FBD

Description
SEND_CFG allows the dynamic configuration of serial transmission parameters for a PtP
communication port. Any queued messages within a CM or CB are discarded when
SEND_CFG is executed.

STEP 7 automatically creates the DB when you insert the instruction.

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You can set up the initial static configuration of the port in the device configuration
properties, or just use the default values. You can execute the SEND_CFG instruction in
your program to change the configuration.
The SEND_CFG configuration changes are not permanently stored in the CPU. The
parameters configured in the device configuration are restored when the CPU transitions
from RUN to STOP mode and after a power cycle. See Configuring transmit (send)
parameters (Page 447).
Table 12- 11 Data types for the parameters
Parameter and type

Data type

Description

REQ

Bool

Activate the configuration change on the rising edge of this input.. (Default
value: False)

PORT

RTSONDLY

UInt

Number of milliseconds to wait after enabling RTS before any Tx data
transmission occurs. This parameter is only valid when hardware flow
control is enabled. The valid range is 0 - 65535 ms. A value of 0 disables
the feature. (Default value: 0)

RTSOFFDLY

UInt

Number of milliseconds to wait after the Tx data transmission occurs before
RTS is disabled: This parameter is only valid when hardware flow control is
enabled. The valid range is 0 - 65535 ms. A value of 0 disables the feature.
(Default value: 0)

BREAK

UInt

This parameter specifies that a break will be sent upon the start of each
message for the specified number of bit times. The maximum is 65535 bit
times up to an eight second maximum. A value of 0 disables the feature.
(Default value: 12)

IDLELINE

UInt

This parameter specifies that the line will remain idle for the specified
number of bit times before the start of each message. The maximum is
65535 bit times up to an eight second maximum. A value of 0 disables the
feature. (Default value: 12)

DONE

OUT

Bool

TRUE for one execution after the last request was completed with no error

ERROR

OUT

Bool

TRUE for one execution after the last request was completed with an error

STATUS

OUT

Word

Execution condition code (Default value: 0)

Table 12- 12 Condition codes
STATUS (W#16#....)

Description

80B0

Transmit interrupt configuration is not allowed. Contact customer suport.

80B1

Break time is greater than the maximum allowed value.

80B2

Idle time is greater than the maximum allowed value.

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12.3.1.4

RCV_CFG instruction

Table 12- 13 RCV_CFG (Receive Configuration) instruction
LAD / FBD

Description
RCV_CFG performs dynamic configuration of serial receiver parameters for a PtP
communication port. This instruction configures the conditions that signal the start and end
of a received message. Any queued messages within a CM or CB are discarded when
RCV_CFG is executed.

STEP 7 automatically creates the DB when you insert the instruction.

You can set up the initial static configuration of the communication port in the device
configuration properties, or just use the default values. You can execute the RCV_CFG
instruction in your program to change the configuration.
The RCV_CFG configuration changes are not permanently stored in the CPU. The
parameters configured in the device configuration are restored when the CPU transitions
from RUN to STOP mode and after a power cycle. See Configuring receive parameters
(Page 447) for more information.
Table 12- 14 Data types for the parameters
Parameter and type

Data type

Description

REQ

Bool

Activate the configuration change on the rising edge of this input.
(Default value: False)

PORT

After you install and configure a CM or CB communication device,
the port identifier appears in the parameter helper drop-list available
at the PORT box connection. The assigned CM or CB port value is
the device configuration property "hardware identifier". The port
symbolic name is assigned in the "System constants" tab of the PLC
tag table. (Default value: 0)

CONDITIONS

The Conditions data structure specifies the starting and ending
message conditions as described below.

DONE

OUT

Bool

TRUE for one scan, after the last request was completed with no
error

ERROR

OUT

Bool

TRUE for one scan, after the last request was completed with an
error

STATUS

OUT

Word

Execution condition code (Default value: 0)

Start conditions for the RCV_PTP instruction
The RCV_PTP instruction uses the configuration specified by the RCV_CFG instruction to
determine the beginning and ending of point-to-point communication messages. The start of
a message is determined by the start conditions. The start of a message can be determined
by one or a combination of start conditions. If more than one start condition is specified, all
the conditions must be satisfied before the message is started.
See the topic "Configuring receive parameters (Page 448)" for a description of the message
start conditions.
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Parameter CONDITIONS data type structure part 1 (start conditions)
Table 12- 15 CONDITIONS structure for start conditions
Parameter and type
STARTCOND

Data type

Description

UInt

Specifies the start condition (Default value: 1)


01H - Start Char



02H - Any Char



04H - Line Break



08H - Idle Line



10H - Sequence 1



20H - Sequence 2



40H - Sequence 3



80H - Sequence 4

IDLETIME

UInt

The number of bit times required for idle line timeout. (Default value:
40). Only used with an idle line condition. 0 to 65535

STARTCHAR

Byte

The start character used with the start character condition. (Default
value: B#16#2)

STRSEQ1CTL

Byte

Sequence 1 ignore/compare control for each character: (Default
value: B#16#0)
These are the enabling bits for each character in start sequence


01H - Character 1



02H - Character 2



04H - Character 3



08H - Character 4

 10H - Character 5
Disabling the bit associated with a character means any character
will match, in this sequence position.
STRSEQ1

Char[5]

Sequence 1 start characters (5 characters). Default value: 0

STRSEQ2CTL

Byte

Sequence 2 ignore/compare control for each character. Default
value: B#16#0)

STRSEQ2

Char[5]

Sequence 2 start characters (5 characters). Default value: 0

STRSEQ3CTL

Byte

Sequence 3 ignore/compare control for each character. Default
value: B#16#0

STRSEQ3

Char[5]

Sequence 3 start characters (5 characters). Default value: 0

STRSEQ4CTL

Byte

Sequence 4 ignore/compare control for each character. Default
value: B#16#0

STRSEQ4

Char[5]

Sequence 4 start characters (5 characters), Default value: 0

Example
Consider the following received hexadecimal coded message: "68 10 aa 68 bb 10 aa 16"
and the configured start sequences shown in the table below. Start sequences begin to be
evaluated when the first 68H character is successfully received. Upon successfully receiving
the fourth character (the second 68H), then start condition 1 is satisfied. Once the start
conditions are satisfied, the evaluation of the end conditions begins.
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The start sequence processing can be terminated due to various parity, framing, or intercharacter timing errors. These errors result in no received message, because the start
condition was not satisfied.
Table 12- 16 Start conditions
Start condition

First Character

First Character +1

First Character +2

First Character +3

First Character +4

68H

10H

aaH

dcH

aaH

e5H

End conditions for the RCV_PTP instruction
The end of a message is determined by the specification of end conditions. The end of a
message is determined by the first occurrence of one or more configured end conditions.
The section "Message end conditions" in the topic "Configuring receive parameters
(Page 448)" describes the end conditions that you can configure in the RCV_CFG
instruction.
You can configure the end conditions in either the properties of the communication interface
in the device configuration, or from the RCV_CFG instruction. Whenever the CPU transitions
from STOP to RUN, the receive parameters (both start and end conditions) return to the
device configuration settings. If the STEP 7 user program executes RCV_CFG, then the
settings are changed to the RCV_CFG conditions.

Parameter CONDITIONS data type structure part 2 (end conditions)
Table 12- 17 CONDITIONS structure for end conditions
Parameter

Parameter type

Data type

Description

ENDCOND

UInt
0

This parameter specifies message end condition:


01H - Response time



02H - Message time



04H - Inter-character gap



08H - Maximum length



10H - N + LEN + M



20H - Sequence

MAXLEN

UInt
1

Maximum message length: Only used when the
maximum length end condition is selected. 1 to 1024
bytes

UInt
0

Byte position within the message of the length field. Only
used with the N + LEN + M end condition. 1 to 1022
bytes

LENGTHSIZE

UInt
0

Size of the byte field (1, 2, or 4 bytes). Only used with the
N + LEN + M end condition.

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Parameter

Parameter type

Data type

Description

LENGTHM

UInt
0

Specify the number of characters following the length
field that are not included in the value of the length field.
This is only used with the N + LEN + M end condition. 0
to 255 bytes

RCVTIME

UInt
200

Specify how long to wait for the first character to be
received. The receive operation will be terminated with an
error if a character is not successfully received within the
specified time. This is only used with the response time
condition. (0 to 65535 bit times with an 8 second
maximum)
This parameter is not a message end condition since
evaluation terminates when the first character of a
response is received. It is an end condition only in the
sense that it terminates a receiver operation because no
response is received when a response is expected. You
must select a separate end condition.

MSGTIME

UInt
200

Specify how long to wait for the entire message to be
completely received once the first character has been
received. This parameter is only used when the message
timeout condition is selected. (0 to 65535 milliseconds)

CHARGAP

UInt
12

Specify the number of bit times between characters. If the
number of bit times between characters exceeds the
specified value, then the end condition will be satisfied.
This is only used with the inter-character gap condition.
(0 to 65535 bit times up to 8 second maximum)

ENDSEQ1CTL

Byte
B#16#0

Sequence 1 ignore/compare control for each character:

Char[5]
0

Sequence 1 start characters (5 characters)

ENDSEQ1

These are the enabling bits for each character for the end
sequence. Character 1 is bit 0, character 2 is bit 1, …,
character 5 is bit 4. Disabling the bit associated with a
character means any character will match, in this
sequence position.

Table 12- 18 Condition codes
STATUS (W#16#....)

Description

80C0

Illegal start condition selected

80C1

Illegal end condition selected, no end condition selected

80C2

Receive interrupt enabled and this is not possible.

80C3

Maximum length end condition is enabled and max length is 0 or > 1024.

80C4

Calculated length is enabled and N is >= 1023.

80C5

Calculated length is enabled and length is not 1, 2 or 4.

80C6

Calculated length is enabled and M value is > 255.

80C7

Calculated length is enabled and calculated length is > 1024.

80C8

Response timeout is enabled and response timeout is zero.

80C9

Inter-character gap timeout is enabled and it is zero.

80CA

Idle line timeout is enabled and it is zero.
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STATUS (W#16#....)

Description

80CB

End sequence is enabled but all chars are "don't care".

80CC

Start sequence (any one of 4) is enabled but all characters are "don't care".

12.3.1.5

SEND_PTP instruction

Table 12- 19 SEND_PTP (Send Point-to-Point data) instruction
LAD / FBD

Description
SEND_PTP initiates the transmission of the data and transfers the assigned buffer to the
communication interface. The CPU program continues while the CM or CB sends the data at
the assigned baud rate. Only one send operation can be pending at a given time. The CM or
CB returns an error if a second SEND_PTP is executed while the CM or CB is already
transmitting a message.

STEP 7 automatically creates the DB when you insert the instruction.

Table 12- 20 Data types for the parameters
Parameter and type

Data type

Description

REQ

Bool

Activates the requested transmission on the rising edge of this transmission
enable input. This initiates transfer of the contents of the buffer to the Point-toPoint communication interface. (Default value: False)

PORT

After you install and configure a CM or CB communication device, the port
identifier appears in the parameter helper drop-list available at the PORT box
connection. The assigned CM or CB port value is the device configuration
property "hardware identifier". The port symbolic name is assigned in the
"System constants" tab of the PLC tag table. (Default value: 0)

BUFFER

Variant

This parameter points to the starting location of the transmit buffer. (Default
value: 0)

LENGTH

UInt

PTRCL

Bool

Note: Boolean data or Boolean arrays are not supported.
Transmitted frame length in bytes (Default value: 0)
When transmitting a complex structure, always use a length of 0.
This parameter selects the buffer as normal point-to-point or specific Siemensprovided protocols that are implemented within the attached CM or CB.
(Default value: False)
FALSE = user program controlled point-to-point operations. (only valid option)
DONE

OUT

Bool

TRUE for one scan, after the last request was completed with no error

ERROR

OUT

Bool

TRUE for one scan, after the last request was completed with an error

STATUS

OUT

Word

Execution condition code (Default value: 0)

While a transmit operation is in progress, the DONE and ERROR outputs are FALSE. When
a transmit operation is complete, either the DONE or the ERROR output will be set TRUE to
show the status of the transmit operation. While DONE or ERROR is TRUE, the STATUS
output is valid.
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The instruction returns a status of 16#7001 if the communication interface accepts the
transmit data. Subsequent SEND_PTP executions return 16#7002, if the CM or CB is still
busy transmitting. When the transmit operation is complete, the CM or CB returns the status
of the transmit operation as 16#0000 (if no errors occurred). Subsequent executions of
SEND_PTP with REQ low return a status of 16#7000 (not busy).
The following diagrams show the relationship of the output values to REQ. This assumes
that the instruction is called periodically to check for the status of the transmission process.
In the diagram below, it is assumed that the instruction is called every scan (represented by
the STATUS values).

The following diagram shows how the DONE and STATUS parameters are valid for only one
scan if the REQ line is pulsed (for one scan) to initiate the transmit operation.

The following diagram shows the relationship of DONE, ERROR and STATUS parameters
when there is an error.

The DONE, ERROR and STATUS values are only valid until SEND_PTP executes again
with the same instance DB.
Table 12- 21 Condition codes
STATUS (W#16#....)

Description

80D0

New request while transmitter active

80D1

Transmit aborted because of no CTS within wait time

80D2

Transmit aborted because of no DSR from the DCE device

80D3

Transmit aborted because of queue overflow (transmit more than 1024 bytes)

833A

The DB for the BUFFER parameter does not exist.

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Interaction of the LENGTH and BUFFER parameters for SEND_PTP
The minimum size of data that can be transmitted by the SEND_PTP instruction is one byte.
The BUFFER parameter determines the size of the data to be transmitted. You cannot use
the data type Bool or arrays of Bool for the BUFFER parameter.
You can always set the LENGTH parameter to 0 and ensure that SEND_PTP sends the
entire data structure represented by the BUFFER parameter. If you only want to send part of
a data structure in the BUFFER parameter, you can set LENGTH as follows:
Table 12- 22 LENGTH and BUFFER parameters
LENGTH

BUFFER

Description

Not used

The complete data is sent as defined at the BUFFER parameter. You do not
need to specify the number of transmitted bytes when LENGTH = 0.

Elementary data type

The LENGTH value must contain the byte count of this data type. For
example, for a Word value, the LENGTH must be two. For a Dword or Real,
the LENGTH must be four. Otherwise, nothing is transferred and the error
8088H is returned.

Structure

The LENGTH value can contain a byte count less than the complete byte
length of the structure, in which case only the first LENGTH bytes of the
structure are sent from the BUFFER. Since the internal byte organization of
a structure cannot always be determined, you might get unexpected results.
In this case, use a LENGTH of 0 to send the complete structure.

Array

The LENGTH value must contain a byte count that is less than the complete
byte length of the array and which must be a multiple of the data element
byte count. For example, the LENGTH parameter for an array of Words
must be a multiple of two and for an array of Reals, a multiple of four. When
LENGTH is specified, the number of array elements which are contained in
LENGTH bytes is transferred. If your BUFFER, for example, contains an
array of 15 Dwords (60 total bytes), and you specify a LENGTH of 20, then
the first five Dwords in the array are transferred.
The LENGTH value must be a multiple of the data element byte count.
Otherwise, STATUS = 8088H, ERROR = 1, and no transmission occurs.

String

The LENGTH parameter contains the number of characters to be
transmitted. Only the characters of the String are transmitted. The maximum
and actual length bytes of the String are not transmitted.

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12.3.1.6

RCV_PTP instruction

Table 12- 23 RCV_PTP (Receive Point-to-Point) instruction
LAD / FBD

Description
RCV_PTP checks for messages that have been received in the CM or CB. If a message is
available, it will be transferred from the CM or CB to the CPU. An error returns the
appropriate STATUS value.

STEP 7 automatically creates the DB when you insert the instruction.

Table 12- 24 Data types for the parameters
Parameter and type

Data type

Description

EN_R

Bool

When this input is TRUE and a message is available, the message is
transferred from the CM or CB to the BUFFER. When EN_R is FALSE, the CM
or CB is checked for messages and NDR, ERROR and STATUS output are
updated, but the message is not transferred to the BUFFER. (Default value: 0)

PORT

After you install and configure a CM or CB communication device, the port
identifier appears in the parameter helper drop-list available at the PORT box
connection. The assigned CM or CB port value is the device configuration
property "hardware identifier". The port symbolic name is assigned in the
"System constants" tab of the PLC tag table. (Default value: 0)

BUFFER

Variant

This parameter points to the starting location of the receive buffer. This buffer
should be large enough to receive the maximum length message.

NDR

OUT

Bool

TRUE for one execution when new data is ready and operation is complete
with no errors.

ERROR

OUT

Bool

TRUE for one execution after the operation was completed with an error.

STATUS

OUT

Word

Execution condition code (Default value: 0)

LENGTH

OUT

UInt

Length of the returned message in bytes (Default value: 0)

Boolean data or Boolean arrays are not supported. (Default value: 0)

The STATUS value is valid when either NDR or ERROR is TRUE. The STATUS value
provides the reason for termination of the receive operation in the CM or CB. This is typically
a positive value, indicating that the receive operation was successful and that the receive
process terminated normally. If the STATUS value is negative (the Most Significant Bit of the
hexadecimal value is set), the receive operation was terminated for an error condition such
as parity, framing, or overrun errors.
Each PtP communication interface can buffer up to a maximum of 1024 bytes. This could be
one large message or several smaller messages. If more than one message is available in
the CM or CB, the RCV_PTP instruction returns the oldest message available. A subsequent
RCV_PTP instruction execution returns the next oldest message available.

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Table 12- 25 Condition codes
STATUS (W#16#...)

Description

0000

No buffer present

80E0

Message terminated because the receive buffer is full

80E1

Message terminated due to parity error

80E2

Message terminated due to framing error

80E3

Message terminated due to overrun error

80E4

Message terminated because calculated length exceeds buffer size

0094

Message terminated due to received maximum character length

0095

Message terminated because of message timeout

0096

Message terminated because of inter-character timeout

0097

Message terminated because of response timeout

0098

Message terminated because the "N+LEN+M" length condition was satisfied

0099

Message terminated because of end sequence was satisfied

833A

The DB for the BUFFER parameter does not exist.

12.3.1.7

RCV_RST instruction

Table 12- 26 RCV_RST (Receiver Reset) instruction
LAD / FBD

Description
RCV_RST clears the receive buffers in the CM or CB.

STEP 7 automatically creates the DB when you insert the instruction.

Table 12- 27 Data types for parameters
Parameter and type

Data type

Description

REQ

Bool

Activates the receiver reset on the rising edge of this enable input (Default
value: False)

PORT

After you install and configure a CM or CB communication device, the port
identifier appears in the parameter helper drop-list available at the PORT box
connection. The assigned CM or CB port value is the device configuration
property "hardware identifier". The port symbolic name is assigned in the
"System constants" tab of the PLC tag table. (Default value: 0)

DONE

OUT

Bool

When TRUE for one scan, indicates that the last request was completed
without errors.

ERROR

OUT

Bool

When TRUE, shows that the last request was completed with errors. Also,
when this output is TRUE, the STATUS output will contain related error codes.

STATUS

OUT

Word

Error code (Default value: 0)

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12.3.1.8

SGN_GET instruction

Table 12- 28 SGN_GET (Get RS232 signals) instruction
LAD / FBD

Description
SGN_GET reads the current states of RS232 communication signals.
This function is valid only for the RS232 CM.

STEP 7 automatically creates the DB when you insert the instruction.

Table 12- 29 Data types for the parameters
Parameter and type

Data type

Description

REQ

Bool

Get RS232 signal state values on the rising edge of this input (Default value:
False)

PORT

After you install and configure a CM or CB communication device, the port
identifier appears in the parameter helper drop-list available at the PORT box
connection. The assigned CM or CB port value is the device configuration
property "hardware identifier". The port symbolic name is assigned in the
"System constants" tab of the PLC tag table.

NDR

OUT

Bool

TRUE for one scan, when new data is ready and the operation is complete
with no errors

ERROR

OUT

Bool

TRUE for one scan, after the operation was completed with an error

STATUS

OUT

Word

Execution condition code (Default value: 0)

DTR

OUT

Bool

Data terminal ready, module ready (output). Default value: False

DSR

OUT

Bool

Data set ready, communication partner ready (input). Default value: False

RTS

OUT

Bool

Request to send, module ready to send (output). Default value: False

CTS

OUT

Bool

Clear to send, communication partner can receive data (input). Default value:
False

DCD

OUT

Bool

Data carrier detect, receive signal level (always False, not supported)

RING

OUT

Bool

Ring indicator, indication of incoming call (always False, not supported)

Table 12- 30 Condition codes
STATUS (W#16#....)

Description

80F0

CM or CB is RS485 and no signals are available

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12.3.1.9

SGN_SET instruction

Table 12- 31 SGN_SET (Set RS232 signals) instruction
LAD / FBD

Description
SGN_SET sets the states of RS232 communication signals.
This function is valid only for the RS232 CM.

STEP 7 automatically creates the DB when you insert the instruction.

Table 12- 32 Data types for parameters
Parameter and type

Data type

Description

REQ

Bool

Start the set RS232 signals operation, on the rising edge of this input
(Default value: False)

PORT

After you install and configure a CM or CB communication device, the
port identifier appears in the parameter helper drop-list available at the
PORT box connection. The assigned CM or CB port value is the device
configuration property "hardware identifier". The port symbolic name is
assigned in the "System constants" tab of the PLC tag table. (Default
value: 0)

SIGNAL

Byte

Selects which signal to set: (multiple allowed). Default value: 0


01H = Set RTS



02H = Set DTR



04H = Set DSR

RTS

Bool

Request to send, module ready to send value to set (true or false),
Default value: False

DTR

Bool

Data terminal ready, module ready to send value to set (true or false).
Default value: False

DSR

Bool

Data set ready (only applies to DCE type interfaces), not used.

DONE

OUT

Bool

TRUE for one execution after the last request was completed with no
error

ERROR

OUT

Bool

TRUE for one execution after the last request was completed with an
error

STATUS

OUT

Word

Execution condition code (Default value: 0)

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Table 12- 33 Condition codes
STATUS (W#16#....)

Description

80F0

CM or CB is RS485 and no signals can be set

80F1

Signals cannot be set because of Hardware flow control

80F2

Cannot set DSR because module is DTE

80F3

Cannot set DTR because module is DCE

12.3.2

Configuring the communication ports
The communication interfaces can be configured by two methods:
● Use the device configuration in STEP 7 to configure the port parameters (baud and
parity), the send parameters and the receive parameters. The device configuration
settings are stored in the CPU. These settings are applied after a power cycle and a RUN
to STOP transition.
● Use the PORT_CFG (Page 430), SEND_CFG (Page 431) and RCV_CFG (Page 433)
instructions to set the parameters. The port settings set by the instructions are valid while
the CPU is in RUN mode. The port settings revert to the device configuration settings
after a STOP transition or power cycle.
After configuring the hardware devices (Page 103), you configure parameters for the
communication interfaces by selecting one of the CMs in your rack or the CB, if configured.
The "Properties" tab of the inspector window
displays the parameters of the selected CM or
CB. Select "Port configuration" to edit the
following parameters:






Baud rate
Parity
Number of stop bits
Flow control (RS232 only)
Wait time

Except for flow control, which only the CM 1241 RS232 supports, the port configuration
parameters are the same regardless of whether you are configuring an RS232 or an RS485
communication module or the RS485 communication board. The parameter values can
differ.
The STEP 7 user program can also configure the port or change the existing configuration
with the PORT_CFG instruction (Page 430).

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Note
Parameter values set from the PORT_CFG instruction in the user program override port
configuration settings set from the device configuration. Note that the S7-1200 does not
retain parameters set from the PORT_CFG instruction in the event of power down.

Parameter

Definition

Baud rate

The default value for the baud rate is 9.6 Kbits per second. Valid choices are: 300 baud,
600 baud, 1.2 Kbits, 2.4 Kbits, 4.8 Kbits, 9.6 Kbits, 19.2 Kbits, 38.4 Kbits, 57.6 Kbits, 76.8
Kbits, and 115.2 Kbits.

Parity

The default value for parity is no parity. Valid choices are: No parity, even, odd, mark (parity
bit always set to 1), and space (parity bit always set to 0).

Number of stop bits

The number of stop bits can be either one or two. The default is one.

Flow control

For the RS232 communication module, you can select either hardware or software flow
control, as described in the section "Managing flow control (Page 445)". If you select
hardware flow control, you can select whether the RTS signal is always on, or RTS is
switched. If you select software flow control, you can define the ASCII characters for the
XON and XOFF characters.
The RS485 communication interfaces do not support flow control.

Wait time

12.3.2.1

Wait time specifies the time that the CM or CB waits to receive CTS after asserting RTS, or
for receiving an XON after receiving an XOFF, depending on the type of flow control. If the
wait time expires before the communication interface receives an expected CTS or XON,
the CM or CB aborts the transmit operation and returns an error to the user program. You
specify the wait time in milliseconds. The range is 0 to 65535 milliseconds.

Managing flow control
Flow control refers to a mechanism for balancing the sending and receiving of data
transmissions so that no data is lost. Flow control ensures that a transmitting device is not
sending more information than a receiving device can handle. Flow control can be
accomplished through either hardware or software. The RS232 CM supports both hardware
and software flow control. The RS485 CM and CB do not support flow control. You specify
the type of flow control either when you configure the port (Page 444) or with the
PORT_CFG instruction (Page 430).
Hardware flow control works through the Request-to-send (RTS) and Clear-to-send (CTS)
communication signals. With the RS232 CM, the RTS signal is output from pin 7 and the
CTS signal is received through pin 8. The RS232 CM is a DTE (Data Terminal Equipment)
device which asserts RTS as an output and monitors CTS as an input.

Hardware flow control: RTS switched
If you enable RTS switched hardware flow control for an RS232 CM, the module sets the
RTS signal active to send data. It monitors the CTS signal to determine whether the
receiving device can accept data. When the CTS signal is active, the module can transmit
data as long as the CTS signal remains active. If the CTS signal goes inactive, then the
transmission must stop.

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Transmission resumes when the CTS signal becomes active. If the CTS signal does not
become active within the configured wait time, the module aborts the transmission and
returns an error to the user program. You specify the wait time in the port configuration
(Page 444).
The RTS switched flow control is useful for devices that require a signal that the transmit is
active. An example would be a radio modem that uses RTS as a "Key" signal to energize the
radio transmitter. The RTS switched flow control will not function with standard telephone
modems. Use the RTS always on selection for telephone modems.

Hardware flow control: RTS always on
In RTS always on mode, the CM 1241 sets RTS active by default. A device such as a
telephone modem monitors the RTS signal from the CM and utilizes this signal as a clear-tosend. The modem only transmits to the CM when RTS is active, that is, when the telephone
modem sees an active CTS. If RTS is inactive, the telephone module does not transmit to
the CM.
To allow the modem to send data to the CM at any time, configure "RTS always on"
hardware flow control. The CM thus sets the RTS signal active all the time. The CM will not
set RTS inactive even if the module cannot accept characters. The transmitting device must
ensure that it does not overrun the receive buffer of the CM.

Data Terminal Block Ready (DTR) and Data Set Ready (DSR) signal utilization
The CM sets DTR active for either type of hardware flow control. The module transmits only
when the DSR signal becomes active. The state of DSR is only evaluated at the start of the
send operation. If DSR becomes inactive after transmission has started, the transmission will
not be paused.

Software flow control
Software flow control uses special characters in the messages to provide flow control. These
characters are ASCII characters that represent XON and XOFF.
XOFF indicates that a transmission must stop. XON indicates that a transmission can
resume. XOFF and XON must not be the same character.
When the transmitting device receives an XOFF character from the receiving device, it stops
transmitting. Transmitting resumes when the transmitting device receives an XON character.
If it does not receive an XON character within the wait time that is specified in the port
configuration (Page 444), the CM aborts the transmission and returns an error to the user
program.
Software flow control requires full-duplex communication, as the receiving partner must be
able to send XOFF to the transmitting partner while a transmission is in progress. Software
flow control is only possible with messages that contain only ASCII characters. Binary
protocols cannot utilize sofware flow control.

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12.3.3

Configuring the transmit (send) and receive parameters
Before the CPU can engage in PtP communications, you must configure parameters for
transmitting (or sending) messages and receiving messages. These parameters dictate how
communications operate when messages are being transmitted to or received from a target
device.

12.3.3.1

Configuring transmit (send) parameters
From the device configuration, you
configure how a communication
interface transmits data by
specifying the "Transmit message
configuration" properties for the
selected interface.

You can also dynamically configure or change the transmit message parameters from the
user program by using the SEND_CFG (Page 431) instruction.
Note
Parameter values set from the SEND_CFG instruction in the user program override the port
configuration settings. Note that the CPU does not retain parameters set from the
SEND_CFG instruction in the event of power down.

Parameter

Definition

RTS On delay

Specifies the amount of time to wait after activating RTS before transmission is initiated.
The range is 0 to 65535 ms, with a default value of 0. This parameter is valid only when the
port configuration (Page 444) specifies hardware flow control. CTS is evaluated after the
RTS On delay time has expired.
This parameter is applicable for RS232 modules only.

RTS Off delay

Specifies the amount of time to wait before de-activating RTS after completion of
transmission. The range is 0 to 65535 ms, with a default value of 0. This parameter is valid
only when the port configuration (Page 444) specifies hardware flow control.

Send break at message start

Specifies that upon the start of each message, a break will be sent after the RTS On delay
(if configured) has expired and CTS is active.

This parameter is applicable for RS232 modules only.
Number of bit times in a
break
Send idle line after a break
Idle line after a break

You specify how many bit times constitute a break where the line is held in a spacing
condition. The default is 12 and the maximum is 65535, up to a limit of eight seconds.
Specifies that an idle line will be sent before message start. It is sent after the break, if a
break is configured. The "Idle line after a break" parameter specifies how many bit times
constitute an idle line where the line is held in a marking condition. The default is 12 and
the maximum is 65535, up to a limit of eight seconds.

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12.3.3.2

Configuring receive parameters
From the device configuration, you
configure how a communication
interface receives data, and how it
recognizes both the start of and
the end of a message. Specify
these parameters in the Receive
message configuration for the
selected interface.

You can also dynamically configure or change the receive message parameters from the
user program by using the RCV_CFG instruction (Page 433).
Note
Parameter values set from the RCV_CFG instruction in the user program override the port
configuration settings. Note that the CPU does not retain parameters set from the RCV_CFG
instruction in the event of power down.

Message start conditions
You can determine how the communication interface recognizes the start of a message. The
start characters and the characters comprising the message go into the receive buffer until a
configured end condition is met.
You can specify multiple start conditions. If you specify more than one start condition, all of
the start conditions must be met before the message is considered started. For example, if
you configure an idle line time and a specific start character, the CM or CB will first look for
the idle line time requirement to be met and then the CM will look for the specified start
character. If some other character is received (not the specified start character), the CM or
CB will restart the start of message search by again looking for an idle line time.
Parameter

Definition

Start on Any Character

The Any Character condition specifies that any successfully received character indicates the
start of a message. This character is the first character within a message.

Line Break

The Line Break conditions specifies that a message receive operation starts after a break
character is received.

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Parameter

Definition

Idle Line

The Idle Line condition specifies that a message reception starts once the receive line has
been idle or quiet for the number of specified bit times. Once this condition occurs, the start
of a message begins.

཰

ཱ

ི

① Characters
② Restarts the idle line timer
③ Idle line is detected and message receive is started
Special condition:
Recognize message start
with single character
Special condition:
Recognize message start
with a character sequence

Specifies that a particular character indicates the start of a message. This character is then
the first character within a message. Any character that is received before this specific
character is discarded. The default character is STX.
Specifies that a particular character sequence from up to four configured sequences
indicates the start of a message. For each sequence, you can specify up to five characters.
For each character position, you specify either a specific hex character, or that the character
is ignored in sequence matching (wild-card character). The last specific character of a
character sequence terminates that start condition sequence.
Incoming sequences are evaluated against the configured start conditions until a start
condition has been satisfied. Once the start sequence has been satisfied, evaluation of end
conditions begins.
You can configure up to four specific character sequences. You use a multiple-sequence
start condition when different sequences of characters can indicate the start of a message. If
any one of the character sequences is matched, the message is started.

The order of checking start conditions is:
● Idle line
● Line break
● Characters or character sequences
While checking for multiple start conditions, if one of the conditions is not met, the CM or CB
will restart the checking with the first required condition. After the CM or CB establishes that
the start conditions have been met, it begins evaluating end conditions.

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Sample configuration - start message on one of two character sequences
Consider the following start message condition configuration:

With this configuration, the start condition is satisfied when either pattern occurs:
● When a five-character sequence is received where the first character is 0x6A and the fifth
character is 0x1C. The characters at positions 2, 3, and 4 can be any character with this
configuration. After the fifth character is received, evaluation of end conditions begins.
● When two consecutive 0x6A characters are received, preceded by any character. In this
case, evaluation of end conditions begins after the second 0x6A is received (3
characters). The character preceding the first 0x6A is included in the start condition.
Example sequences that would satisfy this start condition are:
● 6A 6A
● 6A 12 14 18 1C
● 6A 44 A5 D2 1C

Message end conditions
You also configure how the communication interface recognizes the end of a message. You
can configure multiple message end conditions. If any one of the configured conditions
occurs, the message ends.
For example, you could specify an end condition with an end of message timeout of 300
milliseconds, an inter-character timeout of 40 bit times, and a maximum length of 50 bytes.
The message will end if the message takes longer than 300 milliseconds to receive, or if the
gap between any two characters exceeds 40 bit times, or if 50 bytes are received.

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Parameter

Definition

Recognize message end by
message timeout

The message end occurs when the configured amount of time to wait for the message end
has expired. The message timeout period begins when a start condition has been satisfied.
The default is 200 ms and the range is 0 to 65535 ms.

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ི

① Received characters
②Start Message condition satisfied: message timer starts
③ Message timer expires and terminates the message
Recognize message end by
response timeout

The message end occurs when the configured amount of time to wait for a response
expires before a valid start sequence is received. The response timeout period begins
when a transmission ends and the CM or CB begins the receive operation. The default
response timeout is 200 ms and the range is 0 to 65535 ms. If a character is not received
within the response time period, RCVTIME, then an error is returned to the corresponding
RCV_PTP instruction. The response timeout does not define a specific end condition. It
only specifies that a character must be successfully received within the specified time. You
must configure another end condition to indicate the actual end of a message.

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5&97,0(

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① Transmitted characters
② Received characters
③ First character must be successfully received by this time.

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Parameter

Definition

Recognize message end by
inter-character gap

The message end occurs when the maximum configured timeout between any two
consecutive characters of a message has expired. The default value for the inter-character
gap is 12 bit times and the maximum number is 65535 bit times, up to a maximum of eight
seconds.

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ི

① Received characters
② Restarts the intercharacter timer
③ The intercharacter timer expires and terminates the message.
Recognize message end by
max length

The message end occurs when the configured maximum number of characters has been
received. The valid range for maximum length is 1 to 1023.
This condition can be used to prevent a message buffer overrun error. When this end
condition is combined with timeout end conditions and the timeout condition occurs, any
valid received characters are provided even if the maximum length is not reached. This
allows support for varying length protocols when only the maximum length is known.

Read message length from
message

The message itself specifies the length of the message. The message end occurs when a
message of the specified length has been received. The method for specifying and
interpreting the message length is described below.

Recognize message end
with a character

The message end occurs when a specified character is received.

Recognize message end
with a character sequence

The message end occurs when a specified character sequence is received. You can
specify a sequence of up to five characters. For each character position, you specify either
a specific hex character, or that the character is ignored in sequence matching.
Leading characters that are ignored characters are not part of the end condition. Trailing
characters that are ignored characters are part of the end condition.

Sample configuration - end message with a character sequence
Consider the following end message condition configuration:

In this case, the end condition is satisfied when two consecutive 0x7A characters are
received, followed by any two characters. The character preceding the 0x7A 0x7A pattern is
not part of the end character sequence. Two characters following the 0x7A 0x7A pattern are
required to terminate the end character sequence. The values received at character
positions 4 and 5 are irrelevant, but they must be received to satisfy the end condition.

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Specification of message length within the message
When you select the special condition where the message length is included in the message,
you must provide three parameters that define information about the message length.
The actual message structure varies according to the protocol in use. The three parameters
are as follows:
● n: the character position (1-based) within the message that starts the length specifier
● Length size: The number of bytes (one, two, or four) of the length specifier
● Length m: the number of characters following the length specifier that are not included in
the length count
The ending characters do not need to be contiguous. The "Length m" value can be used to
specify the length of a checksum field whose size is not included in the length field.
These fields appear in the Receive message configuration of the device properties:

Example 1: Consider a message structured according to the following protocol:
STX

Len
(n)

ADR

STX

0x0C

Characters 3 to 14 counted by the length
PKE
4

INDEX
5

xxxx

PWD
7

xxxx

STW
9

xxxx

HSW
11

xxxx

BCC
13

xxxx

14
xx

Configure the receive message length parameters for this message as follows:
● n = 2 (The message length starts with byte 2.)
● Length size = 1 (The message length is defined in one byte.)
● Length m = 0 (There are no additional characters following the length specifier that are
not counted in the length count. Twelve characters follow the length specifier.)
In this example, the characters from 3 to 14 inclusive are the characters counted by Len (n).
Example 2: Consider another message structured according to the following protocol:
SD1

Len (n)

SD2

Characters 5 to 10 counted by length
DA

FCS

Data unit=3 bytes

0x06

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Configure the receive message length parameters for this message as follows:
● n = 3 (The message length starts at byte 3.)
● Length size = 1 (The message length is defined in one byte.)
● Length m = 3 (There are three characters following the length specifier that are not
counted in the length. In the protocol of this example, the characters SD2, FCS, and ED
are not counted in the length count. The other six characters are counted in the length
count; therefore the total number of characters following the length specifier is nine.)
In this example, the characters from 5 to 10 inclusive are the characters counted by Len (n).

12.3.4

Programming the PtP communications
STEP 7 provides extended instructions that enable the user program to perform Point-toPoint communications with a protocol designed and specified in the user program. These
instructions can be considered in two categories:
● Configuration instructions
● Communication instructions

Configuration instructions
Before your user program can engage in PtP communication, you must configure the
communication interface port and the parameters for sending data and receiving data.
You can perform the port configuration and message configuration for each CM or CB
through the device configuration or through these instructions in your user program:
● PORT_CFG (Page 430)
● SEND_CFG (Page 431)
● RCV_CFG (Page 433)

Communication instructions
The PtP communication instructions enable the user program to send messages to and
receive messages from the communication interfaces. For information about transferring
data with these instructions, see the section on data consistency (Page 134).
All of the PtP functions operate asynchronously. The user program can use a polling
architecture to determine the status of transmissions and receptions. SEND_PTP and
RCV_PTP can execute concurrently. The communication modules and communication board
buffer the transmit and receive messages as necessary up to a maximum buffer size of 1024
bytes.

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The CMs and CB send messages to and receive messages from the actual point-to-point
devices. The message protocol is in a buffer that is either received from or sent to a specific
communication port. The buffer and port are parameters of the send and receive
instructions:
● SEND_PTP (Page 437)
● RCV_PTP (Page 440)
Additional instructions provide the capability to reset the receive buffer, and to get and set
specific RS232 signals:
● RCV_RST (Page 441)
● SGN_GET (Page 442)
● SGN_SET (Page 443)

12.3.4.1

Polling architecture
The S7-1200 point-to-point instructions must be called cyclically/periodically to check for
received messages. Polling the send will tell the user program when the transmit has
completed.

Polling architecture: master
The typical sequence for a master is as follows:
1. A SEND_PTP instruction initiates a transmission to the CM or CB.
2. The SEND_PTP instruction is executed on subsequent scans to poll for the transmit
complete status.
3. When the SEND_PTP instruction indicates that the transmission is complete, the user
code can prepare to receive the response.
4. The RCV_PTP instruction is executed repeatedly to check for a response. When the CM
or CB has collected a response message, the RCV_PTP instruction copies the response
to the CPU and indicates that new data has been received.
5. The user program can process the response.
6. Go to step 1 and repeat the cycle.

Polling architecture: slave
The typical sequence for a slave is as follows:
1. The user program executes the RCV_PTP instruction every scan.
2. When the CM or CB has received a request, the RCV_PTP instruction indicates that new
data is ready and the request is copied into the CPU.
3. The user program services the request and generates a response.
4. Use a SEND_PTP instruction to send the response back to the master.
5. Repeatedly execute SEND_PTP to be sure the transmit occurs.
6. Go to step 1 and repeat the cycle.
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The slave must be responsible for calling RCV_PTP frequently enough to receive a
transmission from the master before the master times out while waiting for a response. To
accomplish this task, the user program can call RCV_PTP from a cyclic OB, where the cycle
time is sufficient to receive a transmission from the master before the timeout period expires.
If you set the cycle time for the OB to provide for two executions within the timeout period of
the master, the user program can receive transmissions without missing any.

12.3.5

Example: Point-to-Point communication
In this example, an S7-1200 CPU communicates to a PC with a terminal emulator through a
CM 1241 RS232 module. The point-to-point configuration and STEP 7 program in this
example illustrate how the CPU can receive a message from the PC and echo the message
back to the PC.

...

You must connect the communication interface of the CM 1241 RS232 module to the RS232
interface of the PC, which is normally COM1. Because both of these ports are Data Terminal
Equipment (DTE), you must switch the receive and transmit pins (2 and 3) when connecting
the two ports, which you can accomplish by either of the following methods:
● Use a NULL modem adapter to swap pins 2 and 3 together with a standard RS232 cable.
● Use a NULL modem cable, which already has pins 2 and 3 swapped. You can usually
identify a NULL modem cable as one with two female 9-pin D connector ends.

12.3.5.1

Configuring the communication module
You can configure the CM 1241 from the Device configuration in STEP 7 or with user
program instructions. This example uses the Device configuration method.
● Port configuration: Click the communication port of the CM module from the Device
configuration, and configure the port as shown:

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● Transmit message configuration: Accept the default for transmit message configuration.
No break is to be sent at message start.
● Receive message start configuration: Configure the CM 1241 to start receiving a
message when the communication line is inactive for at least 50 bit times (about 5
milliseconds at 9600 baud = 50 * 1/9600):

● Receive message end configuration: Configure the CM 1241 to end a message when it
receives a maximum of 100 bytes or a linefeed character (10 decimal or A hexadecimal).
The end sequence allows up to five end characters in sequence. The fifth character in the
sequence is the linefeed character. The preceding four end sequence characters are
"don’t care" or unselected characters. The CM 1241 does not evaluate the "don’t care"
characters but looks for a linefeed character preceded by zero or more "don’t care"
characters to indicate the message end.

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12.3.5.2

Programming the STEP 7 program
The example program uses a global data block for the communication buffer, a RCV_PTP
instruction (Page 440) to receive data from the terminal emulator, and a SEND_PTP
instruction (Page 437) to echo the buffer back to the terminal emulator. To program the
example, add the data block configuration and program OB1 as described below.
Global data block "Comm_Buffer": Create a global data block (DB) and name it
"Comm_Buffer". Create one value in the data block called "buffer" with a data type of "array
[0 .. 99] of byte".
Network 1: Enable the RCV_PTP instruction whenever SEND_PTP is not active. Tag_8 at
MW20.0 indicates when sending is complete in Network 4, and when the communication
module is thus ready to receive a message.

Network 2: Use the NDR value (Tag_1 at M0.0) set by the RCV_PTP instruction to make a
copy of the number of bytes received and to set a flag (Tag_8 at M20.0) to trigger the
SEND_PTP instruction.

Network 3: Enable the SEND_PTP instruction when the M20.0 flag is set. Also use this flag
to set the REQ input to TRUE for one scan. The REQ input tells the SEND_PTP instruction
that a new request is to be transmitted. The REQ input must only be set to TRUE for one
execution of SEND_PTP. The SEND_PTP instruction is executed every scan until the
transmit completes. The transmit is complete when the last byte of the message has been
transmitted from the CM 1241. When the transmit is complete, the DONE output (Tag_5 at
M10.0) is set TRUE for one execution of SEND_PTP.

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Network 4: monitor the DONE output of SEND_PTP and reset the transmit flag (Tag_8 at
M20.0) when the transmit operation is complete. When the transmit flag is reset, the
RCV_PTP instruction in Network 1 is enabled to receive the next message.

12.3.5.3

Configuring the terminal emulator
You must set up the terminal emulator to support the example program. You can use most
any terminal emulator on your PC, such as HyperTerminal. Make sure that the terminal
emulator is in the disconnected mode before editing the settings as follows:
1. Set the terminal emulator to use the RS232 port on the PC (normally COM1).
2. Configure the port for 9600 baud, 8 data bits, no parity (none), 1 stop bit and no flow
control.
3. Change the settings of the terminal emulator to emulate an ANSI terminal.
4. Configure the terminal emulator ASCII setup to send a line feed after every line (after the
user presses the Enter key).
5. Echo the characters locally so that the terminal emulator displays what is typed.

12.3.5.4

Running the example program
To exercise the example program, follow these steps:
1. Download the STEP 7 program to the CPU and ensure that it is in RUN mode.
2. Click the "connect" button on the terminal emulator to apply the configuration changes
and open a terminal session to the CM 1241.
3. Type characters at the PC and press Enter.
The terminal emulator sends the characters to the CM 1241 and to the CPU. The CPU
program then echoes the characters back to the terminal emulator.

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12.4

Universal serial interface (USS) communication
The USS instructions control the operation of motor drives which support the universal serial
interface (USS) protocol. You can use the USS instructions to communicate with multiple
drives through RS485 connections to CM 1241 RS485 communication modules or a CB
1241 RS485 communication board. Up to three CM 1241 RS485 modules and one CB 1241
RS485 board can be installed in a S7-1200 CPU. Each RS485 port can operate up to
sixteen drives.
The USS protocol uses a master-slave network for communications over a serial bus. The
master uses an address parameter to send a message to a selected slave. A slave itself can
never transmit without first receiving a request to do so. Direct message transfer between
the individual slaves is not possible. USS communication operates in half-duplex mode. The
following USS illustration shows a network diagram for an example drive application.
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12.4.1

Requirements for using the USS protocol
The four USS instructions use 1 FB and 3 FCs to support the USS protocol. One
USS_PORT instance data block (DB) is used for each USS network. The USS_PORT
instance data block contains temporary storage and buffers for all drives on that USS
network. The USS instructions share the information in this data block.
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All drives (up to 16) connected to a single RS485 port are part of the same USS network. All
drives connected to a different RS485 port are part of a different USS network. Each USS
network is managed using a unique data block. All instructions associated with a single USS
network must share this data block. This includes all USS_DRV, USS_PORT, USS_RPM,
and USS_WPM instructions used to control all drives on a single USS network.
The USS_DRV instruction is a Function Block (FB). When you place the USS_DRV
instruction into the program editor, you will be prompted by the "Call options" dialog to assign
a DB for this FB. If this is the first USS_DRV instruction in this program for this USS network,
then you can accept the default DB assignment (or change the name if you wish) and the
new DB is created for you. If however this is not the first USS_DRV instruction for this
channel, then you must use the drop-down list in the "Call options" dialog to select the DB
name that was previously assigned for this USS network.
Instructions USS_PORT, USS_RPM, and USS_WPM are all Functions (FCs). No DB is
assigned when you place these FCs in the editor. Instead, you must assign the appropriate
DB reference to the "USS_DB" input of these instructions. Double-click on the parameter
field and then click on the parameter helper icon to see the available DB names).

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The USS_PORT function handles the actual communication between the CPU and the
drives via the Point-to-Point (PtP) RS485 communication port. Each call to this function
handles one communication with one drive. Your program must call this function fast enough
to prevent a communication timeout by the drives. You may call this function in a main
program cycle OB or any interrupt OB.
The USS_DRV function block provides your program access to a specified drive on the USS
network. Its inputs and outputs are the status and controls for the drive. If there are 16 drives
on the network, your program must have at least 16 USS_DRV calls, one for each drive.
These blocks should be called at the rate that is required to control the operation of the drive.
Typically, you should call the USS_PORT function from a cyclic interrupt OB. The cycle time
of the cyclic interrupt OB should be set to about half of the minimum call interval (As an
example, 1200 baud communication should use a cyclic time of 350 ms or less).
You may only call the USS_DRV function block from a main program cycle OB.
CAUTION
Only call USS_DRV, USS_RPM, and USS_WPM from a main program cycle OB. The
USS_PORT function can be called from any OB, usually from a cyclic interrupt OB.
Do not use instructions USS_DRV, USS_RPM, or USS_WPM in a higher priority OB than
the corresponding USS_PORT instruction. For example, do not place the USS_PORT in
the main and a USS_RPM in a cyclic interrupt OB. Failure to prevent interruption of
USS_PORT execution may produce unexpected errors.
The USS_RPM and USS_WPM functions read and write the remote drive operating
parameters. These parameters control the internal operation of the drive. See the drive
manual for the definition of these parameters. Your program can contain as many of these
functions as necessary, but only one read or write request can be active per drive, at any
given time. You may only call the USS_RPM and USS_WPM functions from a main program
cycle OB.

Calculating the time required for communicating with the drive
Communications with the drive are asynchronous to the S7-1200 scan cycle. The S7-1200
typically completes several scans before one drive communications transaction is
completed.
The USS_PORT interval is the time required for one drive transaction. The table below
shows the minimum USS_PORT interval for each communication baud rate. Calling the
USS_PORT function more frequently than the USS_PORT interval will not increase the
number of transactions. The drive timeout interval is the amount of time that might be taken
for a transaction, if communications errors caused 3 tries to complete the transaction. By
default, the USS protocol library automatically does up to 2 retries on each transaction.

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Table 12- 34 Calculating the time requirements

12.4.2

Baud rate

Calculated minimum USS_PORT call
Interval ( milliseconds )

Drive message interval timeout per
drive ( milliseconds )

1200

790

2370

2400

405

1215

4800

212.5

638

9600

116.3

349

19200

68.2

205

38400

44.1

133

57600

36.1

109

115200

28.1

USS_DRV instruction

Table 12- 35 USS_DRV instruction
LAD / FBD

Description

Default view

The USS_DRV instruction exchanges data with a drive by creating request messages and
interpreting the drive response messages. A separate function block should be used for each
drive, but all USS functions associated with one USS network and PtP communication port must
use the same instance data block. You must create the DB name when you place the first
USS_DRV instruction and then reference the DB that was created by the initial instruction usage.
STEP 7 automatically creates the DB when you insert the instruction.

Expanded view

LAD and FBD: Expand the box to reveal all the parameters by clicking the bottom of the box. The parameter pins that
are grayed are optional and parameter assignment is not required.

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Table 12- 36 Data types for the parameters
Parameter and type

Data type

Description

RUN

Bool

Drive start bit: When true, this input enables the drive to run at the
preset speed. When RUN goes to false while a drive is running, the
motor will be ramped down to a stop. This behavior differs from the
dropping power (OFF2) or braking the motor (OFF3).

OFF2

Bool

Electrical stop bit: When false, this bit cause the drive to coast to a stop
with no braking.

OFF3

Bool

Fast stop bit: When false, this bit causes a fast stop by braking the
drive rather than just allowing the drive to coast to a stop.

F_ACK

Bool

Fault acknowledge bit: This bit is set to reset the fault bit on a drive.
The bit is set after the fault is cleared to indicate to the drive it no longer
needs to indicate the previous fault.

DIR

Bool

Drive direction control: This bit is set to indicate that the direction is
forward (for positive SPEED_SP).

DRIVE

USInt

Drive address: This input is the address of the USS drive. The valid
range is drive 1 to drive 16.

PZD_LEN

USInt

Word length: This is the number of words of PZD data. The valid values
are 2, 4, 6, or 8 words. The default value is 2.

SPEED_SP

Real

Speed set point: This is the speed of the drive as a percentage of
configured frequency. A positive value specifies forward direction
(when DIR is true). Valid range is 200.00 to -200.00.

CTRL3

Word

Control word 3: A value written to a user-configurable parameter on the
drive. You must configure this on the drive. (optional parameter)

CTRL4

Word

Control word 4: A value written to a user-configurable parameter on the
drive. You must configure this on the drive. (optional parameter)

CTRL5

Word

Control word 5: A value written to a user-configurable parameter on the
drive. You must configure this on the drive. (optional parameter)

CTRL6

Word

Control word 6: A value written to a user-configurable parameter on the
drive. You must configure this on the drive. (optional parameter)

CTRL7

Word

Control word 7: A value written to a user-configurable parameter on the
drive. You must configure this on the drive. (optional parameter)

CTRL8

Word

Control word 8: A value written to a user-configurable parameter on the
drive. You must configure this on the drive. (optional parameter)

NDR

OUT

Bool

New data ready: When true, the bit indicates that the outputs contain
data from a new communication request.

ERROR

OUT

Bool

Error occurred: When true, this indicates that an error has occurred and
the STATUS output is valid. All other outputs are set to zero on an
error. Communication errors are only reported on the USS_PORT
instruction ERROR and STATUS outputs.

STATUS

OUT

Word

The status value of the request indicates the result of the scan. This is
not a status word returned from the drive.

RUN_EN

OUT

Bool

Run enabled: This bit indicates whether the drive is running.

D_DIR

OUT

Bool

Drive direction: This bit indicates whether the drive is running forward.

INHIBIT

OUT

Bool

Drive inhibited: This bit indicates the state of the inhibit bit on the drive.

FAULT

OUT

Bool

Drive fault: This bit indicates that the drive has registered a fault. You
must fix the problem and then set the F_ACK bit to clear this bit when
set.

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Parameter and type

Data type

Description

SPEED

OUT

Real

Drive Current Speed (scaled value of drive status word 2): The value of
the speed of the drive as a percentage of configured speed.

STATUS1

OUT

Word

Drive Status Word 1: This value contains fixed status bits of a drive.

STATUS3

OUT

Word

Drive Status Word 3: This value contains a user-configurable status
word on the drive.

STATUS4

OUT

Word

Drive Status Word 4: This value contains a user-configurable status
word on the drive.

STATUS5

OUT

Word

Drive Status Word 5: This value contains a user-configurable status
word on the drive.

STATUS6

OUT

Word

Drive Status Word 6: This value contains a user-configurable status
word on the drive.

STATUS7

OUT

Word

Drive Status Word 7: This value contains a user-configurable status
word on the drive.

STATUS8

OUT

Word

Drive Status Word 8: This value contains a user-configurable status
word on the drive.

When the initial USS_DRV execution occurs, the drive indicated by the USS address
(parameter DRIVE) is initialized in the Instance DB. After this initialization, subsequent
executions of USS_PORT can begin communication to the drive at this drive number.
Changing the drive number requires a CPU STOP-to-RUN mode transition that initializes the
instance DB. Input parameters are configured into the USS TX message buffer and outputs
are read from a "previous" valid response buffer if any exists. There is no data transmission
during USS_DRV execution. Drives communicate when USS_PORT is executed. USS_DRV
only configures the messages to be sent and interprets data that might have been received
from a previous request.
You can control the drive direction of rotation using either the DIR input (Bool) or using the
sign (positive or negative) with the SPEED_SP input (Real). The following table indicates
how these inputs work together to determine the drive direction, assuming the motor is wired
for forward rotation.
Table 12- 37 Interaction of the SPEED_SP and DIR parameters
SPEED_SP

DIR

Drive rotation direction

Value > 0

Reverse

Value > 0

Forward

Value < 0

Forward

Value < 0

Reverse

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12.4.3

USS_PORT instruction

Table 12- 38 USS_PORT instruction
LAD / FBD

Description
The USS_PORT instruction handles communication over a USS network.

Table 12- 39 Data types for the parameters
Parameter and type

Data type

Description

PORT

Port

After you install and configure a CM or CB communication device, the
port identifier appears in the parameter helper drop-list available at the
PORT box connection. The assigned CM or CB port value is the device
configuration property "hardware identifier". The port symbolic name is
assigned in the "System constants" tab of the PLC tag table.

BAUD

DInt

The baud rate used for USS communication.

USS_DB

INOUT

USS_BASE

The name of the instance DB that is created and initialized when a
USS_DRV instruction is placed in your program.

ERROR

OUT

Bool

When true, this output indicates that an error has occurred and the
STATUS output is valid.

STATUS

OUT

Word

The status value of the request indicates the result of the scan or
initialization. Additional information is available in the
"USS_Extended_Error" variable for some status codes.

Typically, there is only one USS_PORT instruction per PtP communication port in the
program, and each call of this function handles a transmission to or from a single drive. All
USS functions associated with one USS network and PtP communication port must use the
same instance DB.
Your program must execute the USS_PORT instruction often enough to prevent drive
timeouts. USS_PORT is usually called from a cyclic interrupt OB to prevent drive timeouts
and keep the most recent USS data updates available for USS_DRV calls.

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12.4.4

USS_RPM instruction

Table 12- 40 USS_RPM instruction
LAD / FBD

Description
The USS_RPM instruction reads a parameter from a drive. All USS functions associated with one
USS network and PtP communication port must use the same data block. USS_RPM must be
called from a main program cycle OB.

Table 12- 41 Data types for the parameters
Parameter type

Data type

Description

REQ

Bool

Send request: When true, REQ indicates that a new read request is
desired. This is ignored if the request for this parameter is already
pending.

DRIVE

USInt

Drive address: DRIVE is the address of the USS drive. The valid range is
drive 1 to drive 16.

PARAM

UInt

Parameter number: PARAM designates which drive parameter is written.
The range of this parameter is 0 to 2047. On some drives, the most
significant byte can access PARAM values greater than 2047. See your
drive manual for details on how to access an extended range.

INDEX

UInt

Parameter index: INDEX designates which Drive Parameter index is to be
written. A 16-bit value where the Least Significant Byte is the actual index
value with a range of (0 to 255). The Most Significant Byte may also be
used by the drive and is drive-specific. See your drive manual for details.

USS_DB

INOUT

USS_BASE

Then name of the instance DB that is created and initialized when a
USS_DRV instruction is placed in your program.

VALUE

Word, Int, UInt,
DWord, DInt,
UDInt, Real

This is the value of the parameter that was read and is valid only when
the DONE bit is true.

DONE1

OUT

Bool

When true, indicates that the VALUE output holds the previously
requested read parameter value. This bit is set when USS_DRV sees the
read response data from the drive. This bit is reset when either: you
request the response data via another USS_RPM poll, or on the second
of the next two calls to USS_DRV

ERROR

OUT

Bool

Error occurred: When true, ERROR indicates that an error has occurred
and the STATUS output is valid. All other outputs are set to zero on an
error. Communication errors are only reported on the USS_PORT
instruction ERROR and STATUS outputs.

STATUS

OUT

Word

STATUS indicates the result of the read request. Additional information is
available in the "USS_Extended_Error" variable for some status codes.

The DONE bit indicates that valid data has been read from the referenced motor drive and delivered to the CPU. It does
not indicate that the USS library is capable of immediately reading another parameter. A blank PKW request must be
sent to the motor drive and must also be acknowledged by the instruction before the parameter channel for the specific
drive becomes available for use. Immediately calling a USS_RPM or USS_WPM FC for the specified motor drive will
result in a 0x818A error.

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12.4.5

USS_WPM instruction
Note
EEPROM write operations (for the EEPROM inside a USS drive)
Do not overuse the EEPROM permanent write operation. Minimize the number of EEPROM
write operations to extend the EEPROM life.

Table 12- 42 USS_WPM instruction
LAD / FBD

Description
The USS_WPM instruction modifies a parameter in the drive. All USS functions associated with
one USS network and PtP communication port must use the same data block.
USS_WPM must be called from a main program cycle OB.

Table 12- 43 Data types for the parameters
Parameter and type

Data type

Description

REQ

Bool

Send request: When true, REQ indicates that a new write request is
desired. This is ignored if the request for this parameter is already
pending.

DRIVE

USInt

Drive address: DRIVE is the address of the USS drive. The valid range is
drive 1 to drive 16.

PARAM

UInt

INDEX

UInt

Parameter index: INDEX designates which Drive Parameter index is to be
written. A 16-bit value where the least significant byte is the actual index
value with a range of (0 to 255). The most significant byte may also be
used by the drive and is drive-specific. See your drive manual for details.

EEPROM

Bool

Store To Drive EEPROM: When true, a write drive parameter transaction
will be stored in the drive EEPROM. If false, the write is temporary and
will not be retained if the drive is power cycled.

VALUE

Word, Int, UInt,
DWord, DInt,
UDInt, Real

The value of the parameter that is to be written. It must be valid on the
transition of REQ.

USS_DB

INOUT

USS_BASE

The name of the instance DB that is created and initialized when a
USS_DRV instruction is placed in your program.

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Parameter and type

Data type

Description

DONE1

OUT

Bool

When true, DONE indicates that the input VALUE has been written to the
drive. This bit is set when USS_DRV sees the write response data from
the drive. This bit is reset when either you request the response data via
another USS_RPM poll, or on the second of the next two calls to
USS_DRV

ERROR

OUT

Bool

When true, ERROR indicates that an error has occurred and the STATUS
output is valid. All other outputs are set to zero on an error.
Communication errors are only reported on the USS_PORT instruction
ERROR and STATUS outputs.

STATUS

OUT

Word

STATUS indicates the result of the write request. Additional information is
available in the "USS_Extended_Error" variable for some status codes.

12.4.6

USS status codes
USS instruction status codes are returned at the STATUS output of the USS functions.

Table 12- 44 STATUS codes
STATUS
(W#16#....)

Description

0000

No error

8180

The length of the drive response did not match the characters received from the drive. The drive number
where the error occurred is returned in the "USS_Extended_Error" variable. See the extended error
description below this table.

8181

VALUE parameter was not a Word, Real or DWord data type.

8182

The user supplied a Word for a parameter value and received a DWord or Real from the drive in the
response.

8183

The user supplied a DWord or Real for a parameter value and received a Word from the drive in the
response.

8184

The response telegram from drive had a bad checksum. The drive number where the error occurred is
returned in the "USS_Extended_Error" variable. See the extended error description below this table.

8185

Illegal drive address (valid drive address range: 1 to16)

8186

The speed set point is out of the valid range (valid speed SP range: -200% to 200%).

8187

The wrong drive number responded to the request sent. The drive number where the error occurred is
returned in the "USS_Extended_Error" variable. See the extended error description below this table.

8188

Illegal PZD word length specified (valid range = 2, 4, 6 or 8 words)

8189

Illegal Baud Rate was specified.

818A

The parameter request channel is in use by another request for this drive.

818B

The drive has not responded to requests and retries. The drive number where the error occurred is
returned in the "USS_Extended_Error" variable. See the extended error description below this table.

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STATUS
(W#16#....)

Description

818C

The drive returned an extended error on a parameter request operation. See the extended error
description below this table.

818D

The drive returned an illegal access error on a parameter request operation. See your drive manual for
information of why parameter access may be limited.

818E

The drive has not been initialized. This error code is returned to USS_RPM or USS_WPM when
USS_DRV, for that drive, has not been called at least once. This keeps the initialization on first scan of
USS_DRV from overwriting a pending parameter read or write request, since it initializes the drive as a
new entry. To fix this error, call USS_DRV for this drive number.

80Ax-80Fx

Specific errors returned from PtP communication FBs called by the USS Library - These error code
values are not modified by the USS library and are defined in the PtP instruction descriptions.

For several STATUS codes, additional information is provided in the "USS_Extended_Error"
variable of the USS_DRV Instance DB. For STATUS codes hexadecimal 8180, 8184, 8187,
and 818B, USS_Extended_Error contains the drive number where the communication error
occurred. For STATUS code hexadecimal 818C, USS_Extended_Error contains a drive error
code returned from the drive when using a USS_RPM or USS_WPM instruction.
Communication errors (STATUS = 16#818B) are only reported on the USS_PORT
instruction and not on the USS_DRV instruction. For example, if the network is not properly
terminated then it is possible for a drive to go to RUN but the USS_DRV instruction will show
all 0's for the output parameters. In this case, you can only detect the communication error
on the USS_PORT instruction. Since this error is only visible for one scan, you will need to
add some capture logic as illustrated in the following example. In this example, when the
error bit of the USS_PORT instruction is TRUE, then the STATUS and the
USS_Extended_Error values are saved into M memory. The drive number is placed in
USS_Extended_Error variable when the STATUS code value is hexadecimal 8180, 8184,
8187, or 818B.
Network 1 "PortStatus" port status and
"USS_DRV_DB".USS_Extended_Error
extended error code values are only
valid for one program scan. The
values must be captured for later
processing.
Network 2 The "PortError" contact
triggers the storage of the "PortStatus"
value in "LastPortStatus" and the
"USS_DRV_DB".USS_Extended_Error
value in "LastExtError".

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USS drives support read and write access to a drive's internal parameters. This feature
allows remote control and configuration of the drive. Drive parameter access operations can
fail due to errors such as values out of range or illegal requests for a drive's current mode.
The drive generates an error code value that is returned in the "USS_Extended_Error"
variable. This error code value is only valid for the last execution of a USS_RPM or
USS_WPM instruction. The drive error code is put into USS_Extended_Error variable when
the STATUS code value is hexadecimal 818C. The error code value of
"USS_Extended_Error" depends on the drive model. See the drive's manual for a description
of the extended error codes for read and write parameter operations.

12.4.7

General drive setup information

General drive setup requirements
● The drives must be set to use 4 PKW words.
● The drives can be configured for 2, 4, 6, or 8 PZD words.
● The number of PZD word's in the drive must match PZD_LEN input on the USS_DRV
instruction for that drive.
● The baud rate in all the drives must match the BAUD input on the USS_PORT instruction.
● The drive must be set for remote control.
● The drive must be set for frequency set-point to USS on COM Link.
● The drive address must be set to 1 to 16 and match the DRIVE input on the USS_DRV
block for that drive.
● The drive direction control must be set to use the polarity of the drive set-point.
● The RS485 network must be terminated properly.

Connecting a MicroMaster drive
This information about SIEMENS MicroMaster drives is provided as an example. For other
drives, refer to the drive's manual for setup instructions.
To make the connection to a MicroMaster Series 4 (MM4) drive, insert the ends of the RS485 cable into the two caged-clamp, screw-less terminals provided for USS operation.
Standard PROFIBUS cable and connectors can be used to connect the S7-1200.
CAUTION
Interconnecting equipment with different reference potentials can cause unwanted currents
to flow through the interconnecting cable
These unwanted currents can cause communications errors or damage equipment. Be sure
all equipment that you are about to connect with a communications cable either shares a
common circuit reference or is isolated to prevent unwanted current flows. The shield must
be tied to chassis ground or pin 1 on the 9-pin connector. It is recommended that you tie
wiring terminal 2--0V on the MicroMaster drive to chassis ground.

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The two wires at the opposite end of
the RS-485 cable must be inserted into
the MM4 drive terminal blocks. To
make the cable connection on a MM4
drive, remove the drive cover(s) to
access the terminal blocks. See the
MM4 user manual for details about
how to remove the covers(s) of your
specific drive.

A (N)

B (P)

The terminal block connections are labeled numerically. Using a PROFIBUS connector on
the S7-1200 side, connect the A terminal of the cable to the drive terminal 15 (for an MM420)
or terminal 30 (MM440). Connect the B terminal of B (P) A (N) the cable connector to
terminal 14 (MM420) or terminal 29 (MM440).
If the S7-1200 is a terminating node in the network, or if the connection is point-to-point, it is
necessary to use terminals A1 and B1 (not A2 and B2) of the connector since they allow the
termination settings to be set (for example, with DP connector type 6ES7 972--0BA40-0X40).

CAUTION
Make sure the drive covers are replaced properly before supplying power to the unit.

If the drive is configured as the terminating
node in the network, then termination and
P
bias resistors must also be wired to the
N
appropriate terminal connections. This
diagram shows examples of the MM4 drive 0V
connections necessary for termination and
+10 V
bias.

MM420
14
120 ohm
15
470 ohm

1.5K ohm

2
1
MM440

29
120 ohm

N 30
470 ohm
0V

+10 V

1.5K ohm

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Setting up the MM4 drive
Before you connect a drive to the S7-1200, you must ensure that the drive has the following
system parameters. Use the keypad on the drive to set the parameters:
1. Reset the drive to factory settings (optional).

P0010=30
P0970=1

If you skip step 1, then ensure that these parameters are set to the indicated
values.

USS PZD length = P2012 Index 0=(2, 4, 6,
or 8)
USS PKW length = P2013 Index 0=4

2. Enable the read/write access to all parameters (Expert mode).

P0003=3

3. Check the motor settings for your drive. The settings will vary according to
the motor(s) being used.

P0304 = Rated motor voltage (V)
P0305 = Rated motor current (A)
P0307 = Rated motor power (W)
P03010 = Rated motor frequency (Hz)
P0311 = Rated motor speed

To set the parameters P304, P305, P307, P310, and P311, you must first set
parameter P010 to 1 (quick commissioning mode). When you are finished
setting the parameters, set parameter P010 to 0. Parameters P304, P305,
P307, P310, and P311 can only be changed in the quick commissioning
mode.
4. Set the local/remote control mode.

P0700 Index 0=5

5. Set selection of frequency set-point to USS on COM link.

P1000 Index 0=5

6. Ramp up time (optional)
This is the time in seconds that it takes the motor to accelerate to maximum
frequency.

P1120=(0 to 650.00)

7. Ramp down time (optional)
This the time in seconds that it takes the motor to decelerate to a complete
stop.

P1121=(0 to 650.00)

8. Set the serial link reference frequency:

P2000=(1 to 650 Hz)

9. Set the USS normalization:

P2009 Index 0=0

10. Set the baud rate of the RS-485 serial interface:

P2010 Index 0= 4 (2400 baud)
5 (4800 baud)
6 (9600 baud)
7 (19200 baud
8 (38400 baud)
9 (57600 baud)
12 (115200 baud)

11. Enter the Slave address.
Each drive (a maximum of 31) can be operated over the bus.

P2011 Index 0=(0 to 31)

12. Set the serial link timeout.
This is the maximum permissible period between two incoming data
telegrams. This feature is used to turn off the inverter in the event of a
communications failure. Timing starts after a valid data telegram has been
received. If a further data telegram is not received within the specified time
period, the inverter will trip and display fault code F0070. Setting the value to
zero switches off the control.

P2014 Index 0=(0 to 65,535 ms)
0=timeout disabled

13. Transfer the data from RAM to EEPROM:

P0971=1 (Start transfer) Save the changes
to the parameter settings to EEPROM

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12.5

Modbus communication
There are two versions of the Modbus instructions available in STEP 7:
● Version 1 was initially available in STEP 7 Basic V10.5.
● Version 2 is available in STEP 7 Basic/Professional V11. The version 2 design adds REQ
and DONE parameters to MB_COMM_LOAD. Also, the MB_ADDR parameter for
MB_MASTER and MB_SLAVE now allows a UInt value for extended addressing.
For compatibility and ease of migration, you can choose which instruction version to insert
into your user program.
Do not use both 1.x and 2.y instruction versions in the same CPU program. Your program's
Modbus instructions must have the same major version number (1.x, 2.y, or V.z). The
individual instructions within a major version group may have different minor versions (1.x).
Click the icon on the instruction tree task card to enable the headers and columns
of the instruction tree.
To change the version of the Modbus
instructions, select the version from the dropdown list. You can select the group or
individual instructions.
When you use the instruction tree to place a Modbus instruction in your program, a new FB
instance is created in the project tree. You can see new FB instance in the project tree under
PLC_x > Program blocks > System blocks > Program resources.
To verify the version of a Modbus instruction in a program, you must inspect project tree
properties and not the properties of a box displayed in the program editor. Select a project
tree Modbus FB instance, right-click, select "Properties", and select the "Information" page to
see the Modbus instruction version number.

12.5.1

MB_COMM_LOAD

Table 12- 45 MB_COMM_LOAD instruction
LAD / FBD

Description
The MB_COMM_LOAD instruction configures a PtP port for Modbus RTU protocol
communications. Modbus port hardware options: Install up to three CMs (RS485 or RS232), plus
one CB (R4845). An instance data block is assigned automatically when you place the
MB_COMM_LOAD instruction in your program.

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Table 12- 46 Data types for the parameters
Parameter and type

Data type

Description

REQ

Bool

A low to high (positive edge) signal starts the operation.
(Version 2.0 only)

PORT

Port

After you install and configure a CM or CB communication device, the
port identifier appears in the parameter helper drop-list available at the
PORT box connection. The assigned CM or CB port value is the device
configuration property "hardware identifier". The port symbolic name is
assigned in the "System constants" tab of the PLC tag table.

BAUD

UDInt

Baud rate selection:
300, 600, 1200, 2400, 4800, 9600, 19200, 38400, 57600, 76800, 115200,
all other values are invalid

PARITY

FLOW_CTRL

RTS_ON_DLY

RTS_OFF_DLY

RESP_TO

UInt

Parity selection:


0 – None



1 – Odd



2 – Even

Flow control selection:


0 – (default) no flow control



1 – Hardware flow control with RTS always ON (does not apply to
RS485 ports)



2 – Hardware flow control with RTS switched

RTS ON delay selection:


0 – (default) No delay from RTS active until the first character of the
message is transmitted



1 to 65535 – Delay in milliseconds from RTS active until the first
character of the message is transmitted (does not apply to RS485
ports). RTS delays shall be applied independent of the FLOW_CTRL
selection.

RTS OFF delay selection:


0 – (default) No delay from the last character transmitted until RTS
goes inactive



1 to 65535 – Delay in milliseconds from the last character transmitted
until RTS goes inactive (does not apply to RS485 ports). RTS delays
shall be applied independent of the FLOW_CTRL selection.

Response timeout:
Time in milliseconds allowed by MB_MASTER for the slave to respond. If
the slave does not respond in this time period, MB_MASTER will retry the
request or terminate the request with an error when the specified number
of retries has been sent.
5 ms to 65535 ms (default value = 1000 ms).

MB_DB

Variant

A reference to the instance data block used by the MB_MASTER or
MB_SLAVE instructions. After MB_SLAVE or MB_MASTER is placed in
your program, the DB identifier appears in the parameter helper drop-list
available at the MB_DB box connection.

DONE

OUT

Bool

The DONE bit is TRUE for one scan, after the last request was completed
with no error. (Version 2.0 only)

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Parameter and type

Data type

Description

ERROR

OUT

Bool

The ERROR bit is TRUE for one scan, after the last request was
terminated with an error. The error code value at the STATUS parameter
is valid only during the single scan where ERROR = TRUE.

STATUS

OUT

Word

Execution condition code

MB_COMM_LOAD is executed to configure a port for the Modbus RTU protocol. Once a port
is configured for the Modbus RTU protocol, it can only be used by either the MB_MASTER or
MB_SLAVE instructions.
One execution of MB_COMM_LOAD must be used to configure each communication port
that is used for Modbus communication. Assign a unique MB_COMM_LOAD instance DB for
each port that you use. You can install up to three communication modules (RS232 or
RS485) and one communication board (RS485) in the CPU. Call MB_COMM_LOAD from a
startup OB and execute it one time or use the first scan system flag (Page 76) to initiate the
call to execute it one time. Only execute MB_COMM_LOAD again if communication
parameters like baud rate or parity must change.
An instance data block is assigned for MB_MASTER or MB_SLAVE when you place these
instructions in your program. This instance data block is referenced when you specify the
MB_DB parameter for the MB_COMM_LOAD instruction.

MB_COMM_LOAD data block variables
The following table shows the public static variables stored in the instance DB for the
MB_COMM_LOAD that can be used in your program.
Table 12- 47 Static variables in the instance DB
Variable

Data type

Description

ICHAR_GAP

Word

Delay for Inter-character gap between characters. This parameter is specified
in milliseconds and is used to increase the expected amount of time between
received characters. The corresponding number of bit times for this parameter
is added to the Modbus default of 35 bit times (3.5 character times).

RETRIES

Word

Number of retries that the master will attempt before returning the no response
error code 0x80C8.

Table 12- 48 MB_COMM_LOAD execution condition codes
STATUS (W#16#)

Description

0000

No error

8180

Invalid port ID value (wrong port/hardware identifier for communication module)

8181

Invalid baud rate value

8182

Invalid parity value

8183

Invalid flow control value

8184

Invalid response timeout value (response timeout less than the 5 ms minimum)

8185

MB_DB parameter is not an instance data block of a MB_MASTER or MB_SLAVE
instruction.

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12.5.2

MB_MASTER

Table 12- 49 MB_MASTER instruction
LAD / FBD

Description
The MB_MASTER instruction communicates as a Modbus master using a port that was
configured by a previous execution of the MB_COMM_LOAD instruction. An instance data block
is assigned automatically when you place the MB_MASTER instruction in your program. This
MB_MASTER instance data block is used when you specify the MB_DB parameter for the
MB_COMM_LOAD instruction.

Table 12- 50 Data types for the parameters
Parameter and type

Data type

Description

REQ

Bool

A low to high (positive edge) signal starts the operation.

MB_ADDR

V1.0: USInt

Modbus RTU station address:

V2.0: UInt

Standard addressing range (1 to 247)
Extended addressing range (1 to 65535)
The value of 0 is reserved for broadcasting a message to all Modbus
slaves. Modbus function codes 05, 06, 15 and 16 are the only function
codes supported for broadcast.

MODE

USInt

Mode Selection: Specifies the type of request (read, write, or diagnostic).
See the Modbus functions table below for details.

DATA_ADDR

UDInt

Starting Address in the slave: Specifies the starting address of the data to
be accessed in the Modbus slave. See the Modbus functions table below
for valid addresses.

DATA_LEN

UInt

Data Length: Specifies the number of bits or words to be accessed in this
request. See the Modbus functions table below for valid lengths.

DATA_PTR

Variant

Data Pointer: Points to the M or DB address (Standard DB type) for the
data being written or read.

DONE

OUT

Bool

The DONE bit is TRUE for one scan, after the last request was completed
with no error.

BUSY

OUT

Bool



0 – No MB_MASTER operation in progress



1 – MB_MASTER operation in progress

ERROR

OUT

Bool

The ERROR bit is TRUE for one scan, after the last request was
terminated with an error. The error code value at the STATUS parameter
is valid only during the single scan where ERROR = TRUE.

STATUS

OUT

Word

Execution condition code

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Modbus master communication rules
● MB_COMM_LOAD must be executed to configure a port before a MB_MASTER
instruction can communicate with that port.
● If a port is to be used to initiate Modbus master requests, that port should not be used by
MB_SLAVE . One or more instances of MB_MASTER execution can be used with that
port, but all MB_MASTER execution must use the same MB_MASTER instance DB for
that port.
● The Modbus instructions do not use communication interrupt events to control the
communication process. Your program must poll the MB_MASTER instruction for transmit
and receive complete conditions.
● It is recommended that you call all MB_MASTER execution for a given port from a
program cycle OB. Modbus master instructions may execute in only one of the program
cycle or cyclic/time delay execution levels. They must not execute in both execution
priority levels. Pre-emption of a Modbus Master instruction by another Modbus master
instruction in a higher priority execution priority level will result in improper operation.
Modbus master instructions must not execute in the startup, diagnostic or time error
execution priority levels.
● Once a master instruction initiates a transmission, this instance must be continually
executed with the EN input enabled until a DONE=1 state or ERROR=1 state is returned.
A particular MB_MASTER instance is considered active until one of these two events
occurs. While the original instance is active, any call to any other instance with the REQ
input enabled will result in an error. If the continuous execution of the original instance
stops, the request state remains active for a period of time specified by the static variable
Blocked_Proc_Timeout. Once this period of time expires, the next master instruction
called with an enabled REQ input will become the active instance. This prevents a single
Modbus master instance from monopolizing or locking access to a port. If the original
active instance is not enabled within the period of time specified by the static variable
"Blocked_Proc_Timeout", then the next execution by this instance (with REQ not set) will
clear the active state. If (REQ is set), then this execution initiates a new master request
as if no other instance was active.

REQ parameter
REQ value FALSE = No request
REQ value TRUE = Request to transmit data to Modbus Slave(s).
You must supply this input from a positive edge trigger instruction on the first call for
MB_MASTER execution. The edge triggered pulse will invoke the transmission request
once. All inputs are captured and held unchanged for one request and response triggered by
this input. No other MB_MASTER instruction is allowed to issue a request until this request
has been completed.
If the same instance of the call to the MB_MASTER FB is executed again with the REQ input
TRUE before the completion of the request, then no subsequent transmissions will be made.
However, as soon as the current request has been completed, a new request will be issued
if MB_MASTER is executed with the REQ input set to true. The recommended edge
triggered pulse keeps the REQ input FALSE for subsequent executions as you test for
DONE bit = TRUE.

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DATA_ADDR and MODE parameters select the Modbus function type
DATA_ADDR (starting Modbus address in the slave): Specifies the starting address of the
data to be accessed in the Modbus slave.
The MB_MASTER instruction uses a MODE input rather than a Function Code input. The
combination of MODE and Modbus address determine the Function Code that is used in the
actual Modbus message. The following table shows the correspondence between parameter
MODE, Modbus function code, and Modbus address range.
Table 12- 51 Modbus functions
MODE

Modbus
Function

Data length

Operation and data

Modbus
Address

1 to 2000
1 to 1992 1

Read output bits:
1 to (1992 or 2000) bits per request

1 to 9999

1 to 2000
1 to 1992 1

Read input bits:
1 to (1992 or 2000) bits per request

10001 to 19999

1 to 125
1 to 124 1

Read Holding registers:
1 to (124 or 125) words per request

40001 to 49999 or
400001 to 465535

1 to 125
1 to 124 1

Read input words:
1 to (124 or 125) words per request

30001 to 39999

Write one output bit:
One bit per request

1 to 9999

Write one holding register:
1 word per request

40001 to 49999 or
400001 to 465535

2 to 1968
2 to 1960 1

Write multiple output bits:
2 to (1960 or 1968) bits per request

1 to 9999

2 to 123
2 to 122 1

Write multiple holding registers:
2 to (122 or 123) words per request

40001 to 49999 or
400001 to 465535

1 to 1968
2 to 1960 1

Write one or more output bits:
1 to (1960 or 1968) bits per request

1 to 9999

1 to 123
1 to 122 1

Write one or more holding registers:
1 to (122 or 123) words per request

40001 to 49999 or
400001 to 465535

Read the slave communication status word and event
counter. The status word indicates busy (0 – not busy,
0xFFFF - busy). The event counter is incremented for
each successful completion of a message.
Both the DATA_ADDR and DATA_LEN operands of
MB_MASTER are ignored for this function.

Check slave status using data diagnostic code 0x0000
(Loopback test – slave echoes the request)
1 word per request

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MODE

Modbus
Function

Data length

Operation and data

Modbus
Address

Reset slave event counter using data diagnostic code
0x000A
1 word per request

3 to 10,
12 to 79,
82 to 255
1

Reserved

For "Extended Addressing" mode the maximum data lengths are reduced by 1 byte or 1 word depending upon the data
type used by the function.

DATA_PTR parameter
The DATA_PTR parameter points to the DB or M address that is written to or read from. If
you use a data block, then you must create a global data block that provides data storage for
reads and writes to Modbus slaves.
Note
The DATA_PTR data block type must allow direct addressing
The data block must allow both direct (absolute) and symbolic addressing. When you create
the data block the "Standard" access attribute must be selected.

Data block structures for the DATA_PTR parameter
● These data types are valid for word reads of Modbus addresses 30001 to 39999, 40001
to 49999, and 400001 to 465536 and also for word writes to Modbus addresses 40001 to
49999 and 400001 to 465536.
– Standard array of WORD, UINT, or INT data types
– Named WORD, UINT, or INT structure where each element has a unique name and
16 bit data type.
– Named complex structure where each element has a unique name and a 16 or 32 bit
data type.
● For bit reads and writes of Modbus addresses 00001 to 09999 and 10001 to 19999.
– Standard array of Boolean data types.
– Named Boolean structure of uniquely named Boolean variables..
● Although not required, it is recommended that each MB_MASTER instruction have its
own separate memory area. The reason for this recommendation is that there is a greater
possibility of data corruption if multiple MB_MASTER instructions are reading and writing
to the same memory area.
● There is no requirement that the DATA_PTR data areas be in the same global data block.
You can create one data block with multiple areas for Modbus reads, one data block for
Modbus writes, or one data block for each slave station.

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Modbus master data block variables
The following table shows the public static variables stored in the instance DB for
MB_MASTER that can be used in your program.
Table 12- 52 Static variables in the instance DB
Variable

Data type

Description

Blocked_Proc_Timeout

Real

Amount of time (in seconds) to wait for a blocked Modbus Master instance
before removing this instance as being ACTIVE. This can occur, for example,
when a Master request has been issued and then the program stops calling
the Master function before it has completely finished the request. The time
value must be greater than 0 and less than 55 seconds, or an error occurs.
The default value is .5 seconds.

Extended_Addressing

Bool

Configures single or double-byte slave addressing. The default value = 0.
(0=single byte address, 1=double-byte address)

Your program can write values to the Blocked_Proc_Timeout and Extended_Addressing
variables to control Modbus master operations. See the MB_SLAVE topic description of
HR_Start_Offset and Extended_Addressing for an example of how to use these variables in
the program editor and details about Modbus extended addressing (Page 482).

Condition codes
Table 12- 53 MB_MASTER execution condition codes (communication and configuration errors)
STATUS (W#16#)

Description

0000

No error

80C8

Slave timeout. Check baud rate, parity, and wiring of slave.

80D1

The receiver issued a flow control request to suspend an active transmission and never reenabled the transmission during the specified wait time.
This error is also generated during hardware flow control when the receiver does not assert
CTS within the specified wait time.

80D2

The transmit request was aborted because no DSR signal is received from the DCE.

80E0

The message was terminated because the receive buffer is full.

80E1

The message was terminated as a result of a parity error.

80E2

The message was terminated as a result of a framing error.

80E3

The message was terminated as a result of an overrun error.

80E4

The message was terminated as a result of the specified length exceeding the total buffer size.

8180

Invalid port ID value or error with MB_COMM_LOAD instruction

8186

Invalid Modbus station address

8188

Invalid Mode specified for broadcast request

8189

Invalid Data Address value

818A

Invalid Data Length value

818B

Invalid pointer to the local data source/destination: Size not correct

818C

Invalid pointer for DATA_PTR or invalid Blocked_Proc_Timeout: The data area must be a DB
(that allows both symbolic and direct access) or a M memory.

8200

Port is busy processing a transmit request.

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Table 12- 54 MB_MASTER execution condition codes (Modbus protocol errors)
STATUS (W#16#)

Response code from
slave

Modbus protocol errors

8380

CRC error

8381

Function code not supported

8382

Data length error

8383

Data address error or address outside the valid range of the
DATA_PTR area

8384

Greater than 03

Data value error

8385

Data diagnostic code value not supported (function code 08)

8386

Function code in the response does not match the code in the request.

8387

Wrong slave responded

8388

The slave response to a write request is incorrect. The write request
returned by the slave does not match what the master actually sent.

12.5.3

MB_SLAVE

Table 12- 55 MB_SLAVE instruction
LAD / FBD

Description
The MB_SLAVE instruction allows your program to communicate as a Modbus slave through a
PtP port on the CM (RS485 or RS232) and CB (RS485). When a remote Modbus RTU master
issues a request, your user program responds to the request by MB_SLAVE execution. STEP 7
automatically creates an instance DB when you insert the instruction. Use this MB_SLAVE_DB
name when you specify the MB_DB parameter for the MB_COMM_LOAD instruction.

Table 12- 56 Data types for the parameters
Parameter and type

Data type

Description

MB_ADDR

V1.0: USInt
The station address of the Modbus slave:
V2.0: UInt, Byte, Standard addressing range (1 to 247)
Extended addressing range (0 to 65535)
USInt

MB_HOLD_REG

Variant

Pointer to the Modbus Holding Register DB: The Modbus holding
register can be M memory or a data block.

NDR

OUT

Bool

New Data Ready:


0 – No new data



1 – Indicates that new data has been written by the Modbus
master

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Parameter and type
DR

OUT

Data type

Description

Bool

Data Read:


0 – No data read



1 – Indicates that data has been read by the Modbus master

ERROR

OUT

Bool

The ERROR bit is TRUE for one scan, after the last request was
terminated with an error. If execution is terminated with an error,
then the error code value at the STATUS parameter is valid only
during the single scan where ERROR = TRUE.

STATUS

OUT

Word

Execution error code

Modbus communication function codes (1, 2, 4, 5, and 15) can read and write bits and words
directly in the input process image and output process image of the CPU. For these function
codes, the MB_HOLD_REG parameter must be defined as a data type larger than a byte.
The following table shows the example mapping of Modbus addresses to the process image
in the CPU.
Table 12- 57 Mapping of Modbus addresses to the process image
Modbus functions

S7-1200

Codes

Function

Data area

Address range

Data area

CPU address

Read bits

Output

8192

Output Process Image

Q0.0 to Q1023.7

Read bits

Input

10001

Read words Input

30001

18192

Input Process Image

I0.0 to I1023.7

30512

Input Process Image

IW0 to IW1022

Write bit

Output

8192

Output Process Image

Q0.0 to Q1023.7

Write bits

Output

8192

Output Process Image

Q0.0 to Q1023.7

Modbus communication function codes (3, 6, 16) use a Modbus holding register which can
be a M memory address range or a data block. The type of holding register is specified by
the MB_HOLD_REG parameter on the MB_SLAVE instruction.
Note
MB_HOLD_REG data block type
A Modbus holding register data block must allow both direct (absolute) and symbolic
addressing. When you create the data block the "Standard" access attribute must be
selected.
The following table shows examples of Modbus address to holding register mapping that is
used for Modbus function codes 03 (read words), 06 (write word), and 16 (write words). The
actual upper limit of DB addresses is determined by the maximum work memory limit and M
memory limit, for each CPU model.

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Table 12- 58 Mapping of Modbus addresses to CPU memory
Modbus Master
Address

MW100

DB10.DBw0

MW120

DB10.DBW50

"Recipe".ingredient

40001

MW100

DB10.DBW0

MW120

DB10.DBW50

"Recipe".ingredient[1]

40002

MW102

DB10.DBW2

MW122

DB10.DBW52

"Recipe".ingredient[2]

40003

MW104

DB10.DBW4

MW124

DB10.DBW54

"Recipe".ingredient[3]

40004

MW106

DB10.DBW6

MW126

DB10.DBW56

"Recipe".ingredient[4]

40005

MW108

DB10.DBW8

MW128

DB10.DBW58

"Recipe".ingredient[5]

MB_HOLD_REG parameter examples

Table 12- 59 Diagnostic functions
S7-1200 MB_SLAVE Modbus diagnostic functions
Codes

Sub-function

Description

0000H

Return query data echo test: The MB_SLAVE will echo back to a Modbus master a
word of data that is received.

000AH

Clear communication event counter: The MB_SLAVE will clear out the communication
event counter that is used for Modbus function 11.

Get communication event counter: The MB_SLAVE uses an internal communication
event counter for recording the number of successful Modbus read and write requests
that are sent to the Modbus slave. The counter does not increment on any Function 8,
Function 11, or broadcast requests. It is also not incremented on any requests that
result in a communication error (for example, parity or CRC errors).

The MB_SLAVE instruction supports broadcast write requests from any Modbus master as
long as the request is for accessing valid addresses. MB_SLAVE will produce error code
0x8188 for function codes not supported in broadcast.

Modbus slave communication rules
● MB_COMM_LOAD must be executed to configure a port, before a MB_SLAVE instruction
can communicate through that port.
● If a port is to respond as a slave to a Modbus master, then do not program that port with
the MB_MASTER instruction.
● Only one instance of MB_SLAVE can be used with a given port, otherwise erratic
behavior may occur.
● The Modbus instructions do not use communication interrupt events to control the
communication process. Your program must control the communication process by
polling the MB_SLAVE instruction for transmit and receive complete conditions.
● The MB_SLAVE instruction must execute periodically at a rate that allows it to make a
timely response to incoming requests from a Modbus master. It is recommended that you
execute MB_SLAVE every scan from a program cycle OB. Executing MB_SLAVE from a
cyclic interrupt OB is possible, but is not recommended because of the potential for
excessive time delays in the interrupt routine to temporarily block the execution of other
interrupt routines.

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Modbus signal timing
MB_SLAVE must be executed periodically to receive each request from the Modbus master
and then respond as required. The frequency of execution for MB_SLAVE is dependent
upon the response timeout period of the Modbus master. This is illustrated in the following
diagram.

$'5

'DWD

5HVSRQVH
WLPHRXWSHULRG

&5&

0DVWHUVHQGV
6WDUW
&5& LQWHUYDO FKDUDFWHUWLPHV

$'5

6ODYHVHQGV
5HVSRQVH
GHOD\WLPH

$'5

'DWD

6WDUW
&5& LQWHUYDO

The response timeout period RESP_TO is the amount of time a Modbus master waits for the
start of a response from a Modbus slave. This time period is not defined by the Modbus
protocol, but is a parameter of each Modbus master. The frequency of execution (the time
between one execution and the next execution) of MB_SLAVE must be based on the
particular parameters of your Modbus master. At a minimum, you should execute
MB_SLAVE twice within the response timeout period of the Modbus master.

Modbus slave variables
This table shows the public static variables stored in the MB_SLAVE instance data block that
can be used in your program
Table 12- 60 Modbus slave variables
Variable

Data type

Description

HR_Start_Offset

Word

Specifies the starting address of the Modbus Holding register (default = 0)

Extended_Addressing

Bool

Configures single or double-byte slave addressing
(0=single byte address, 1=double-byte address, default = 0)

Request_Count

Word

The number of all requests received by this slave

Slave_Message_Count

Word

The number of requests received for this specific slave

Bad_CRC_Count

Word

The number of requests received that have a CRC error

Broadcast_Count

Word

The number of broadcast requests received

Exception_Count

Word

Modbus specific errors that require a returned exception

Success_Count

Word

The number of requests received for this specific slave that have no protocol
errors

Your program can write values to the HR_Start_Offset and Extended_Addressing variables
and control Modbus slave operations. The other variables can be read to monitor Modbus
status.

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HR_Start_Offset
Modbus holding register addresses begin at 40001 or 400001. These addresses correspond
to the beginning PLC memory address of the holding register. However, you can configure
the "HR_Start_Offset" variable to start the beginning Modbus holding register address at
another value instead of 40001 or 400001.
For example, if the holding register is configured to start at MW100 and is 100 words long.
An offset of 20 specifies a beginning holding register address of 40021 instead of 40001.
Any address below 40021 and above 400119 will result in an addressing error.
Table 12- 61 Example of Modbus holding register addressing
HR_Start_Offset
0
20

Address

Minimum

Maximum

Modbus address (Word)

40001

40099

S7-1200 address

MW100

MW298

Modbus address (Word)

40021

40119

S7-1200 address

MW100

MW298

HR_Start_Offset is a word value that specifies the starting address of the Modbus holding
register and is stored in the MB_SLAVE instance data block. You can set this public static
variable value by using the parameter helper drop-list, after MB_SLAVE is placed in your
program.
For example, after MB_SLAVE is placed in a LAD network, you can go to a previous network
and assign the HR_Start_Offset value. The value must be assigned prior to execution of
MB_SLAVE.
Entering a Modbus slave variable using the
default DB name:
1. Set the cursor in the parameter field and
type an m character.
2. Select "MB_SLAVE_DB" from the drop-list.
3. Set the cursor at the right side of the DB
name (after the quote character) and enter
a period character.
4. Select "MB_SLAVE_DB.HR_Start_Offset"
from the drop list.

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Extended_Addressing
The Extended_Addressing variable is accessed in a similar way as the HR_Start_Offset
reference discussed above except that the Extended_Addressing variable is a boolean
value. The boolean value must be written by an output coil and not a move box.
Modbus slave addressing can be configured to be either a single byte (which is the Modbus
standard) or double byte. Extended addressing is used to address more than 247 devices
within a single network. Selecting extended addressing allows you to address a maximum of
64000 addresses. A Modbus function 1 frame is shown below as an example.
Table 12- 62 Single-byte slave address (byte 0)
Function 1

Byte 0

Request

Slave addr.

Byte 1
F code

Byte 2

Byte 3

Valid Response

Slave addr.

F code

Length

Error response

Slave addr.

0x81

E code

Byte 4

Start address

Byte 5
Length of coils

Coil data

Table 12- 63 Double-byte slave address (byte 0 and byte 1)
Byte 0

Byte 1

Byte 2

Byte 3

Byte 4

Request

Slave address

F code

Valid Response

Slave address

F code

Length

Error response

Slave address

0x81

E code

Byte 5

Start address

Byte 6
Length of coils

Coil data

Condition codes
Table 12- 64 MB_SLAVE execution condition codes (communication and configuration errors)
STATUS (W#16#)

Description

80D1

80D2

The transmit request was aborted because no DSR signal is received from the DCE.

80E0

The message was terminated because the receive buffer is full.

80E1

The message was terminated as a result of a parity error.

80E2

The message was terminated as a result of a framing error.

80E3

The message was terminated as a result of an overrun error.

80E4

The message was terminated as a result of the specified length exceeding the total buffer
size.

8180

Invalid port ID value or error with MB_COMM_LOAD instruction

8186

Invalid Modbus station address

8187

Invalid pointer to MB_HOLD_REG DB: Area is too small

818C

Invalid MB_HOLD_REG pointer to M memory or DB (DB area must allow both symbolic and
direct address)

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Table 12- 65 MB_SLAVE execution condition codes (Modbus protocol errors)
STATUS (W#16#)

Response code from
slave

Modbus protocol errors

8380

No response

CRC error

8381

Function code not supported or not supported within broadcasts

8382

Data length error

8383

Data address error or address outside the valid range of the
DATA_PTR area

8384

Data value error

8385

Data diagnostic code value not supported (function code 08)

12.5.4

Modbus master sample program
Network 1 Initialize the RS-485 module parameters only once during the first scan.

Network 2 Read 100 words from the slave holding register.

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Network 3 This is an optional network that just shows the values of the first 3 words once the
read operation is done.

Network 4 Write 64 bits to the output image register starting at slave address Q2.0.

12.5.5

Modbus slave sample program
Initialize the RS-485 module parameters only once during the first scan.

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Check for Modbus Master requests during each scan. The Modbus holding register is
configured for 100 words starting at MW1000.

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Web server

The Web server for the S7-1200 provides Web page access to data about your CPU and
process data within the CPU.

Standard Web pages
The S7-1200 includes standard Web pages that you can access from your PC from a Web
browser (Page 492):
● Introduction (Page 495) - entry point to the standard Web pages
● Start Page (Page 496) - general information about the CPU
● Identification (Page 497) - detailed information about the CPU including serial, order, and
version numbers
● Module Information (Page 498) - information about the modules in the local rack
● Communication (Page 500) - information about the network addresses, physical
properties of the communication interfaces, and communication statistics
● Diagnostic Buffer (Page 497) - the diagnostic buffer
● Variable Status (Page 501) - CPU variables and I/O, accessible by address or PLC tag
name
● Data Logs (Page 503) - data log files stored internally in the CPU or on a memory card
These pages are built in to the S7-1200. For details about the standard Web pages, and how
to access them, refer to the Standard web pages (Page 492) section.

User-defined Web pages
The S7-1200 also provides support for you to create user-defined Web pages that can
access CPU data. You can develop these pages with the HTML authoring software of your
choice, and include pre-defined "AWP" (Automation Web Programming) commands in your
HTML code to access CPU data. Refer to the User-defined web pages (Page 508) chapter
for specific information on the development of user-defined Web pages, and the associated
configuration and programming in STEP 7.

Web browser requirement
The following Web browsers support the Web server:
● Internet Explorer 8.0 or greater
● Mozilla Firefox 3.0 or greater
● Opera 11.0 or greater
For browser-related restrictions that can interfere with the display of standard or user-defined
Web pages, see the Constraints (Page 504) section.

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13.1 Enabling the Web server

13.1

Enabling the Web server
You enable the Web server in STEP 7 from Device Configuration for the CPU to which you
intend to connect.
To enable the Web server, follow these steps:
1. Select the CPU in the Device Configuration view.
2. In the inspector window, select "Web server" from the CPU properties.
3. Select the check box for "Enable Web server on this module".
4. If you require secure access to the standard web pages, select the "Permit access only
with HTTPS" check box.
After you download the device configuration, you can use the standard Web pages to access
the CPU. If you select "Enable" for "Automatic update", the pages refresh every ten seconds.
If you created user-defined Web pages, you can access them from the standard Web page
menu.

13.2

Standard web pages

13.2.1

Accessing the standard Web pages from the PC
To access the S7-1200 standard Web pages from a PC, follow these steps:
1. Ensure that the S7-1200 and the PC are on a common Ethernet network or are
connected directly to each other with a standard Ethernet cable.
2. Open a Web browser and enter the URL "http://ww.xx.yy.zz", where "ww.xx.yy.zz"
corresponds to the IP address of the S7-1200 CPU.
The Web browser opens the Introduction page.
Note
If your Internet access prevents direct connection to an IP address, see your IT
administrator. Your Web environment or operating system might also impose other
constraints (Page 504).
Alternatively, you can address your Web browser to a specific standard Web page. To do so,
enter the URL in the form "http://ww.xx.yy.zz/.html", where corresponds to
one of the standard Web pages:
● start (Page 496) - general information about the CPU
● identification (Page 497) - detailed information about the CPU including serial, order, and
version numbers
● module (Page 498) - information about the modules in the local rack

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● communication (Page 500) - information about the network addresses, physical
properties of the communication interfaces, and communication statistics
● diagnostic (Page 497) - the diagnostic buffer
● variable (Page 501) - CPU variables and I/O, accessible by address or PLC tag name
● datalog (Page 503) - data log files stored internally in the CPU or on a memory card
● index (Page 495) - introduction page to enter the standard Web pages
For example, if you enter "http://ww.xx.yy.zz/communication.html", the browser will display
the communication page.

Secure access
You can use https:// instead of http:// for secure access to the standard Web pages. You will
typically get a security warning that you can confirm with "Yes" to proceed to the standard
Web pages. To avoid the security warning with each secure access, you can import the
Siemens software certificate to your Web browser (Page 506).

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13.2.2

Layout of the standard Web pages
Each of the standard Web pages has a common layout with navigational links and page
controls as shown below:

①
②
③
④
⑤
⑥
⑦

4 5

Web server header
Log in or log out
Standard Web page header with name of the page that you are viewing. This example is the
CPU Identification page. Some of the standard Web pages, such as module information, also
display a navigation path here if multiple screens of that type can be accessed.
Refresh icon: for pages with automatic refresh, enables or disables the automatic refresh
function; for pages without automatic refresh, causes the page to update with current data
Print icon: prepares and displays a printable version of the information available from the
displayed page
Navigation area to switch to another page
Content area for specific standard Web page that you are viewing. This example is the CPU
Identification page.

Note
Printing standard Web pages
When printing standard Web page content, note that the printed contents can sometimes
differ from the displayed page. For example, a print copy of the Diagnostic buffer page might
contain new diagnostic entries that are not shown on the Diagnostic buffer page display. If
automatic refresh is not enabled, the page display shows the diagnostic events at the time
the page was initially displayed and the print copy contains the diagnostic events at the time
the print function was executed.

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Logging in
No log in is required to view the data in the standard Web pages. To perform certain actions
such as changing the operating mode of the controller, or writing values to memory, you
must log in as the "admin" user.
The log in frame is near the upper left corner on each page.

To log in as the "admin" user, follow these steps:
1. Enter "admin" for the Name field.
2. Enter the CPU password if one is configured in the Password field; otherwise, press the
Enter key.
You are now logged in as the "admin" user.
If you encounter any errors logging in, return to the Introduction page (Page 495) and
download the Siemens security certificate (Page 506). You can then log in with no errors.

Logging out
To log out the "admin" user, simply click the "Log out" link from any
page.

You can continue to access and view standard Web pages when not logged in, but you
cannot perform the actions that are restricted to the "admin" user. Each of the standard Web
page descriptions defines the actions, if any, that require the "admin" log in.

13.2.3

Introduction
The Introduction page is the welcome screen for entry into the S7-1200 standard Web
pages.

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13.2 Standard web pages

From this page, you click "Enter" to access the S7-1200 standard Web pages. At the top of
the screen are links to useful Siemens Web sites, as well as a link to download the Siemens
security certificate (Page 506).

13.2.4

Start
The Start page displays a representation of the CPU to which you are connected and lists
general information about the CPU. If you log in as the "admin" user, you can also change
the operating mode of the CPU and flash the LEDs.

① and ②

Buttons for flashing LEDs, and changing operating mode only appear on the Start page
when you log in as the "admin" user.

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13.2.5

Identification
The Identification page displays identifying characteristics of the CPU:
● Serial number
● Order numbers
● Version information

The Identification page does not vary with the "admin" login.

13.2.6

Diagnostic Buffer
The diagnostic buffer page displays diagnostic events. From the selector, you can choose
what range of diagnostic buffer entries to display, either 1 to 25 or 26 to 50. The top part of
the page displays those entries with the CPU time and date of when the event occurred. The
times are CPU times, which correspond to the Time of day and Time zone setting in the
device configuration for the CPU. The CPU time is not necessarily the same as the local
time.
From the top part of the page, you can select any individual entry to show detailed
information about that entry in the bottom part of the page.

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The Diagnostic buffer page does not vary with the "admin" login.

13.2.7

Module Information
The module information page provides information about all the modules in the local rack.
The top section of the screen shows a summary of the modules, and the bottom section
shows status and identification of the selected module.

Status display

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Identification display

Drilling down
You can select a link in the top section to drill down to the module information for that
particular module. Modules with submodules have links for each submodule. The type of
information that is displayed varies with the module selected. For example, the module
information dialog initially displays the name of the SIMATIC 1200 station, a status indicator,
and a comment. If you drill down to the CPU, the module information displays the name of
the digital and analog inputs and outputs that the CPU model provides (for example,
"DI14/DO10", "AI2"), addressing information for the I/O, status indicators, slot numbers, and
comments.

As you drill down, the module information page shows the path you have followed. You can
click any link in this path to return to a higher level.

Sorting fields
When the list displays multiple modules, you can click the column header
of a field to sort it either up or down by that field.

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Filtering the module information
You can filter any field in the module information list. From the drop-down list, select the field
name for which you want to filter the data. Enter text in the associated text box and click the
Filter link. The list updates to show you modules that correspond to your filtering criteria.

Status information
The status tab in the bottom section of the module information page displays a description of
the current status of the module that is selected in the top section.

Identification
The identification tab displays the serial number and revision numbers of the selected
module.
The module information page does not vary with the "admin" login.

13.2.8

Communication
The communication page displays the parameters of the connected CPU, and
communications statistics. The Parameter tab shows the MAC address of the CPU, the IP
address and IP settings of the CPU, and physical properties. The Statistics tab shows send
and receive communication statistics.

Communication: Parameter display

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Communication: Statistics display

The communication page does not vary with the "admin" login.

13.2.9

Variable Status
The Variable Status page allows you to view any of the I/O or memory data in your CPU.
You can enter a direct address (such as I0.0), a PLC tag name, or a tag from a specific data
block. For data block tags, you enclose the data block name in double quotation marks. For
each monitor value you can select a display format for the data. You can continue entering
and specifying values until you have as many as you want within the limitations for the page.
The monitor values show up automatically and refresh by default, unless you click the "Off"
icon in the upper right area of the page. When refresh is disabled, you can click "On" to reenable automatic refresh.
With the "admin" log in, you can also modify data values. Enter any values that you wish to
set in the appropriate "Modify Value" field. Click the "Go" button beside a value to write that
value to the CPU. To modify a variable of data type STRING, you must enclose the string in
single quotation marks. You can also enter multiple values and click "Modify All Values" to
write all of the values to the CPU.

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①

The "Modify Value" functionality is only visible and accessible when you are logged in as the
"admin" user.

If you leave the Variable Status page and return, the Variable Status page does not retain
your entries. You can bookmark the page and return to the bookmark to see the same
entries. If you do not bookmark the page, you must re-enter the variables.

Limitations on the Variable Status page
● The maximum number of variable entries per page is 50.
● The maximum number of characters for the URL corresponding to the Variable Status
page is 2083. You can see the URL that represents your current variable page in the
address bar of your browser.
● For the character display format, the page displays hexadecimal values if the actual CPU
values are not valid ASCII characters as interpreted by the browser.
Note
If a tag name displays special characters such that it is rejected as an entry on the
Variable Status page, you can enclose the tag name in double quotation marks. In most
cases, the Variable Status page will then recognize the tag name.

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13.2.10

Data Logs
The Data Logs page allows you to view or download a specified number of data log entries.
With the "admin" log in, you can also clear these entries after downloading them, or you can
delete them. The Web server downloads data logs to your PC in comma-separated values
(CSV) file format.

①
②

The "Download & Clear" option is not available if you are not logged in as the "admin" user.
The "Delete" option is not available if you are not logged in as the "admin" user.

Note
The data log file is in USA/UK comma-separated values format (CSV). To open it in
Microsoft Excel on non-USA/UK systems, you must import it into Microsoft Excel with
specific settings (Page 507).

Recent entries: Downloading a specified number of recent data records
Set the maximum number of recent records to download and then click the Data log name to
initiate a download of the specified number of records. In the output .csv file, the data
records are sorted in decreasing record number order. You will be prompted by Microsoft
Windows to open or save the log file.
By default, the Data Logs page shows the most recent 25 entries of a log file, regardless of
how many entries are actually in the log. You can change this value in the "Maximum most
recent entries to read" field by entering a number or by using the + or - button to increment
or decrement the value. The maximum number of entries per file that you can display or
save is 50.

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Downloading a log file that contains all data records
To download an entire log file, click the Download icon corresponding to a specific log file.
You will be prompted by Microsoft Windows to open or save the log file.
In the output .csv file, all data records are included and sorted in increasing record number
order unless the data log is full and older records (lower record number) are being
overwritten by later records (higher record number).

Downloading and clearing a log file
To download a log file and then clear all the data records, you must be logged in as the
"admin" user. Then click the "Download & Clear" icon corresponding to a specific log file.
You will be prompted by Microsoft Windows to open or save the log file.
After the download is complete, a new "//END" line is inserted after the header record of the
Data log file stored in the PLC. This effectively clears the Data log for future internal PLC
processing, but subsequent downloads of this file will have new data records inserted above
the first "//END" line.
Note
Data log .csv file "//END" marker
The "//END" .csv file end marker is only used for the first ((max records) -1) records to mark
the logical end of the file. Behind the logical end, the file may contain data which may be
interpreted by Excel as additional data records. You should search for the first "//END" then
delete it and all records below it. If the logical end marker is not present, you can sort the
data rows using the record number.

Deleting a log file
To delete a log file, you must be logged in as the "admin" user. Then click the Delete icon
that corresponds to a specific log file. The Web server then deletes the selected log file.

Additional information
For information on programming with the Data log instructions, see the Data logging
(Page 269) chapter.

13.2.11

Constraints
The following IT considerations can affect your use of the Web server:
● Typically, you must use the IP address of the CPU to access the standard Web pages or
user-defined Web pages. If your Web browser does not allow connecting directly to an IP
address, see your IT administrator. If your local policies support DNS, you can connect to
the IP address through a DNS entry to that address.
● Firewalls, proxy settings, and other site-specific restrictions can also restrict access to the
CPU. See your IT administrator to resolve these issues.

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● The standard Web pages use JavaScripts and cookies. If JavaScripts or cookies are
disabled in your Web browser, enable them. If you cannot enable them, some features
will be restricted (Page 505). Use of JavaScripts and cookies in user-defined Web pages
is optional. If used, they must be enabled in your browser.
● Secure Sockets Layer (SSL) is supported by the Web server. You can access the
standard Web pages and user-defined Web pages with an URL of either
http://ww.xx.yy.zz or https://ww.xx.yy.zz, where "ww.xx.yy.zz" represents the IP address
of the CPU.
● Siemens provides a security certificate for secure access to the Web server. From the
Introduction standard Web page (Page 495), you can download and import the certificate
into the Internet options of your Web browser (Page 506). If you choose to not import the
certificate, you will get a security verification prompt every time you access the Web
server with https://.

13.2.11.1

Features restricted when JavaScript is disabled
The standard Web pages are implemented using HTML, JavaScripts, and cookies. If your
site restricts the use of JavaScripts and cookies, then enable them for the pages to function
properly. If you cannot enable JavaScripts for your Web browser, the features controlled by
JavaScripts cannot run.

General
The pages do not update dynamically. You must manually refresh the page with the Refresh
icon (Page 494) to view fresh data.

Diagnostic Buffer page
● Displaying the event details: With JavaScript, you select a row in the diagnostic buffer to
see the details in the bottom section. Without JavaScript, you must click the event field
hyperlink of a diagnostic buffer entry to see the event data in the bottom section.
● Changing the range of diagnostic buffer entries to view: With JavaScript, you use the
drop-down list at the top to select the range of diagnostic buffer entries to view, and the
page automatically updates. Without JavaScript, you use the drop-down list at the top to
select the range of diagnostic buffer entries to view, but you must then click the "Go" link
to update the diagnostic buffer page with the range you selected from the drop-down list.
Note that the "Go" and the event field hyperlinks are only visible when JavaScript is not
enabled. They are not necessary and therefore are not present when JavaScript is enabled.
Note
The Opera V11.0 browser does not support the "Go" button or hyperlinked diagnostic
entries. With Opera V11.0, you cannot access event details or change the range if you have
disabled JavaScript.

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Module Information page
● You cannot filter the data.
● You cannot sort fields.

Variable Status page
● After you enter each variable, you must manually set the focus to the "New variable" row
to enter a new variable.
● Selecting a display format does not automatically change the data value display to the
selected format. You must click the "Monitor value" button to refresh the display with the
new format.

Data Logs page
● You cannot click a file name under "Recent entries" to open or save a log file. You can,
however, use the Download icon for the same functionality.
● The Data Logs page does not refresh.
● The "+" and "-" buttons to increment and decrement the number of recent entries have no
effect.
● Entering a value directly in the number of recent entries does not set the number of
entries. If you attempt to enter a value in this field from Mozilla Firefox, the display goes
blank. You must reselect "Data Logs" from the navigation pane to restore the Data Logs
display. The number of recent entries field remains unchanged.
Note that you can leave the Data Logs page and re-enter to get the most recent 25 entries.

13.2.11.2

Features restricted when cookies are not allowed
If your Web browser does not allow cookies you cannot log in with the "admin" user name.

13.2.11.3

Importing the Siemens security certificate
You can import the Siemens security certificate into your Internet options so that you won't
be prompted for security verification when you enter https://ww.xx.yy.zz in your Web
browser, where "ww.xx.yy.zz" is the IP address of the CPU. If you use an http:// URL and not
an https:// URL, then you do not need to download and install the certificate.

Downloading the certificate
You use the "download certificate" link from the Introduction page (Page 495) to download
the Siemens security certificate to your PC. The procedure varies according to which Web
browser you use:

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Importing the certificate to Internet Explorer
1. Click the "download certificate" link from the Introduction page. A "File Download Security Warning" dialog pops up.
2. From the "File Download - Security Warning" dialog, click "Open" to open the file. A
"Certificate" dialog appears.
3. From the "Certificate" dialog, click the "Install Certificate" button to launch the Certificate
Import Wizard.
4. Follow the dialogs of the "Certificate Import Wizard" to import the certificate, letting the
operating system automatically select the certificate store.

Importing the certificate to Mozilla Firefox
1. Click the "download certificate" link from the Intro page. An "Opening
MiniWebCA_Cer.crt" dialog pops up.
2. Click "Save file" from the "Opening MiniWebCA_Cer.crt" dialog. A "Downloads" dialog
appears.
3. From the "Downloads" dialog, double-click "MiniWebCA_Cer.crt". If you have attempted
the download more than once, multiple copies show up. Just double-click any one of the
"MiniWebCA_Cer.crt". entries.
4. Click "OK" if prompted to open an executable file.
5. Click "Open" on the "Open File - Security Warning" dialog if it appears. A "Certificate"
dialog appears.
6. On the "Certificate" dialog, click the "Install Certificate" button.
7. Follow the dialogs of the "Certificate Import Wizard" to import the certificate, letting the
operating system automatically select the certificate store.
8. If the "Security Warning" dialog appears, click "Yes" to confirm installation of the
certificate.

Other browsers
Follow the conventions of your Web browser to import and install the Siemens certificate.
After you have installed the Siemens security certificate "SIMATIC CONTROLLER" in the
Internet options for your Web browser content, you will not be required to verify a security
prompt when you access the Web server with https:// ww.xx.yy.zz.

13.2.11.4

Importing CSV format data logs to non-USA/UK versions of Microsoft Excel
Data log files are in the comma-separated values (CSV) file format. You can open these files
directly in Microsoft Excel from the Data Logs page when your system is running the USA or
UK version of Microsoft Excel. In other countries, however, this format is not widely used
because commas occur frequently in numerical notation.
To open a data log file that you have saved, follow these steps for non USA/UK versions of
Microsoft Excel:

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1. Open Excel and create an empty workbook.
2. From the "Data > Import External Data" menu, select the "Import Data" command.
3. Navigate to and select the data log file you want to open. The Text Import Wizard starts.
4. From the Text Import Wizard, change the default option for "Original data type" from
"Fixed width" to "Delimited".
5. Click the Next button.
6. From the Step 2 dialog, select the "Comma" check box to change the delimiter type from
"Tab" to "Comma".
7. Click the Next button.
8. From the Step 3 dialog, you can optionally change the Date format from MDY
(month/day/year) to another format.
9. Complete the remaining steps of the Text Import Wizard to import the file.

13.3

User-defined web pages
The S7-1200 Web server also provides the means for you to create your own applicationspecific HTML pages that incorporate data from the PLC. You create these pages using the
HTML editor of your choice and download them to the CPU where they are accessible from
the standard Web page menu. This process involves several tasks:
● Creating HTML pages with an HTML editor, such as Microsoft Frontpage (Page 509)
● Including AWP commands in HTML comments in the HTML code (Page 510):The AWP
commands are a fixed set of commands that Siemens provides for accessing CPU
information.
● Configuring STEP 7 to read and process the HTML pages (Page 522)
● Generating blocks from the HTML pages (Page 522)
● Programming STEP 7 to control the use of the HTML pages (Page 524)
● Compiling and downloading the blocks to the CPU (Page 525)
● Accessing the user-defined Web pages from your PC (Page 526)
This process is illustrated below:

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①

13.3.1

HTML files with embedded AWP commands

Creating HTML pages
You can use the software package of your choice to create your own HTML pages for use
with the Web server. Be sure that your HTML code is compliant to the HTML standards of
the W3C (World Wide Web Consortium). STEP 7 does not perform any verification of your
HTML syntax.
You can use a software package that lets you design in WYSIWYG or design layout mode,
but you need to be able to edit your HTML code in pure HTML form. Most Web authoring
tools provide this type of editing; otherwise, you can always use a simple text editor to edit
the HTML code. Include the following line in your HTML page to set the charset for the page
to UTF-8:

Also be sure to also save the file from the editor in UTF-8 character encoding:
You use STEP 7 to compile everything in your HTML pages into STEP 7 data blocks. These
data blocks consist of one control data block that directs the display of the Web pages and
one or more fragment data blocks that contain the compiled Web pages. Be aware that
extensive sets of HTML pages, particularly those with lots of images, require a significant
amount of load memory space (Page 526) for the fragment DBs. If the internal load memory
of your CPU is not sufficient for your user-defined Web pages, use a memory card (Page 95)
to provide external load memory.
To program your HTML code to use data from the S7-1200, you include AWP commands
(Page 510) as HTML comments. When finished, save your HTML pages to your PC and
note the folder path where you save them.

Refreshing user-defined Web pages
User-defined Web pages do not automatically refresh. It is your choice whether to program
the HTML to refresh the page or not. For pages that display PLC data, refreshing periodically
keeps the data current. For HTML pages that serve as forms for data entry, refreshing can
interfere with the user entering data. If you want your entire page to automatically refresh,
you can add this line to your HTML header, where "10" is the number of seconds between
refreshes:

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You can also use JavaScripts or other HTML techniques to control page or data refreshing.
For this, refer to documentation on HTML and JavaScript.

13.3.2

AWP commands supported by the S7-1200 Web server
The S7-1200 Web server provides AWP commands that you embed in your user-defined
Web pages as HTML comments for the following purposes:
● Reading variables (Page 511)
● Writing variables (Page 512)
● Reading special variables (Page 513)
● Writing special variables (Page 514)
● Defining enum types (Page 516)
● Assigning variables to enum types (Page 517)
● Creating fragment data blocks (Page 519)

General syntax
Except for the command to read a variable, the AWP commands are of the following syntax:

You use the AWP commands in conjunction with typical HTML form commands to write to
variables in the CPU.
The descriptions of the AWP commands in the following pages use the following
conventions:
● Items enclosed in brackets [ ] are optional.
● Items enclosed in angle brackets < > are parameter values to be specified.
● Quotation marks are a literal part of the command. They must be present as indicated.
● Special characters in tag or data block names, depending on usage, must be escaped or
enclosed in quotation marks (Page 521).
Use a text editor or HTML editing mode to insert AWP commands into your pages.

AWP command summary
The details for using each AWP command are in the topics to follow, but here is a brief
summary of the commands:
Reading variables
:=:
Writing variables

This AWP command merely declares the variable in the Name clause to be writable. Your
HTML code performs writes to the variable by name from ,

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Braking: %

Note
Only an admin user can write data to the CPU. The commands are ignored if the user has
not logged in as the admin user.
If a tag name or data block name includes special characters, you must use additional
quotation marks or escape characters as described in the topic "Handling tag names that
contain special characters (Page 521)".

13.3.2.3

Reading special variables
The Web server provides the ability to read values from the PLC to store in special variables
in the HTTP response header. You might, for example, want to read a pathname from a PLC
tag to redirect the URL to another location using the HEADER:Location special variable.

Syntax

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Parameters

The type of special variable and is one of the following:
HEADER
COOKIE_VALUE
COOKIE_EXPIRES

Refer to HTTP documentation for a list of all the names of HEADER variables. A
few examples are listed below:
Status: response code
Location: path for redirection
Retry-After: how long service is expected to be unavailable to the requesting client
For types COOKIE_VALUE and COOKIE_EXPIRES, is the name of a
specific cookie.
COOKIE_VALUE:name: value of the named cookie
COOKIE_EXPIRES:name: expiration time in seconds of named cookie
The Name clause must be enclosed in single or double quotation marks.
If no Use clause is specified, the special variable name corresponds to a PLC tag
name. Enclose the complete Name clause within single quotation marks and the
PLC tag in double quotation marks. The special variable name and PLC tag name
must match exactly.

Name of the PLC tag or data block tag for the variable to be read into
The Varname must be enclosed in single quotation marks. Within the single
quotes, use double quotation marks around a PLC tag or data block name. The
data block name is within the double quotes but not the data block tag name. Note
that for data block tags, you use the name of the block and not a data block
number.

Examples

In this example, the HTTP special variable "HEADER:Status" receives the value of the PLC
tag "HEADER:Status". The name in the PLC tag table must match the name of the special
variable exactly if no Use clause is specified.

In this example, the HTTP special variable "HEADER:Status" receives the value of the PLC
tag "Status".
If a tag name or data block name includes special characters, you must use additional
quotation marks or escape characters as described in the topic Handling tag names that
contain special characters (Page 521).

13.3.2.4

Writing special variables
The Web server provides the ability to write values to the CPU from special variables in the
HTTP request header. For example, you can to store information in STEP 7 about the cookie
associated with a user-defined Web page, the user that is accessing a page, or header
information. The Web server provides access to specific special variables that you can write
to the CPU when logged in as the admin user.

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Syntax

Parameters

The type of special variable and is one of the following:
HEADER
SERVER
COOKIE_VALUE

Specific variable within the types defined above, as shown in these examples:
HEADER:Accept: content types that are acceptable
HEADER:User-Agent: information about the user agent originating the request.
SERVER:current_user_id: id of the current user; 0 if no user logged in
SERVER:current_user_name: name of the current user
COOKIE_VALUE:: value of the named cookie
Enclose the Name clause in single quotation marks.
If no Use clause is specified, the special variable name corresponds to a PLC
variable name. Enclose the complete Name clause within single quotation marks
and the PLC tag in double quotation marks. The special variable name must match
the PLC tag name exactly.
Refer to HTTP documentation for a list of all the names of HEADER variables.

The variable name in your STEP 7 program into which you want to write the special
variable, which can be a PLC tag name, or a data block tag.
The Varname must be enclosed in single quotation marks. Within the single
quotes, use double quotation marks around a PLC tag or data block name. The
data block name is within the double quotes but not the data block tag name. Note
that for data block tags, you use the name of the block and not a data block
number.

Examples

In this example, the Web page writes the value of the HTTP special variable
"SERVER:current_user_id" to the PLC tag named "SERVER:current_user_id ".

In this example, the Web page writes the value of the HTTP special variable
"SERVER:current_user_id" to the PLC tag named "my_userid".

Note
Only an admin user can write data to the CPU. The commands are ignored if the user has
not logged in as the admin user.

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If a tag name or data block name includes special characters, you must use additional
quotation marks or escape characters as described in the topic "Handling tag names that
contain special characters (Page 521)".

13.3.2.5

Using an alias for a variable reference
You can use an alias in your user-defined Web page for an In_Variable or an Out_Variable.
For example, you can use a different symbolic name in your HTML page than the one used
in the CPU, or you can equate a variable in the CPU with a special variable. The AWP Use
clause provides this capability.

Syntax

<-- AWP_In_Variable Name='' Use='' -->
<-- AWP_Out_Variable Name='' Use='' -->

Parameters

Examples

The alias name or special variable name
Varname1 must be enclosed in single or double quotation marks.

Name of the PLC variable for which you want to assign an alias name. The variable
can be a PLC tag, a data block tag, or a special variable. Varname2 must be
enclosed in single quotation marks. Within the single quotes, use double quotation
marks around a PLC tag, special variable, or data block name. The data block
name is within the double quotes but not the data block tag name. Note that for
data block tags, you use the name of the block and not a data block number.

<-- AWP_In_Variable Name='SERVER:current_user_id'
Use='"Data_Block_10".server_user' -->
In this example, the special variable SERVER:current_user_id is written to the tag
"server_user" in data block "Data_Block_10".
<-- AWP_Out_Variable Name='Weight'
Use='"Data_Block_10".Tank_data.Weight' -->
In this example, the value in data block structure member Data_Block_10.Tank_data.Weight
can be referenced simply by "Weight" throughout the rest of the user-defined Web page.
<-- AWP_Out_Variable Name='Weight' Use='"Raw_Milk_Tank_Weight"' -->
In this example, the value in the PLC tag "Raw_Milk_Tank_Weight" can be referenced simply
by "Weight" throughout the rest of the user-defined Web page.
If a tag name or data block name includes special characters, you must use additional
quotation marks or escape characters as described in the topic Handling tag names that
contain special characters (Page 521).

13.3.2.6

Defining enum types
You can define enum types in your user-defined pages and assign the elements in an AWP
command.
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Syntax

Parameters

Name of the enumerated type, enclosed in single or double quotation marks.
:
The constant indicates the numerical value for the enum type assignment. The total
number is unbounded.
The name is the value assigned to the enum element.

Note that the entire string of enum value assignments is enclosed in single quotation marks,
and each individual enum type element assignment is enclosed in double quotation marks.
The scope of an enum type definition is global for the user-defined Web pages. If you have
set up your user-defined Web pages in language folders (Page 538), the enum type
definition is global for all pages in the language folder.

Example

13.3.2.7

Referencing CPU variables with an enum type
You can assign a variable in the CPU to an enum type. This variable can be used elsewhere
in your user-defined Web page in a read operation (Page 511) or a write operation
(Page 512). On a read operation, the Web server will replace the numerical value that is
read from the CPU with the corresponding enum text value. On a write operation, the Web
server will replace the text value with the integer value of the enumeration that corresponds
to the text before writing the value to the CPU.

Syntax

Parameters

Name of PLC tag or data block tag to associate with the enum type, or the name of
the alias name for a PLC tag (Page 516) if declared.
Varname must be enclosed in single quotation marks. Within the single quotes, use
double quotation marks around a PLC tag or data block name. Note that for data
block tags, you use the name of the block and not a data block number. The data
block name is within the double quotes but not the data block tag name.

Name of the enumerated type, which must be enclosed in single or double
quotation marks

The scope of an enum type reference is the current fragment.

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Example declaration

Example usage in a variable read

...
The current value of "Alarm" is :="Alarm":
If the value of "Alarm" in the CPU is 2, the HTML page displays 'The current value of "Alarm"
is Tank is empty' because the enum type definion (Page 516) assigns the text string "Tank is
empty" to the numerical value 2.

Example usage in a variable write

...

Because the enum type defintion (Page 516) assigns "Tank is full" to the numerical value 1,
the value 1 is written to the PLC tag named "Alarm" in the CPU.
Note that the Name clause in the AWP_In_Variable declaration must correspond exactly to
the Name clause in the AWP_Enum_Ref declaration.

Example usage in a variable write with use of an alias

...

Because the enum type defintion (Page 516) assigns "Tank is full" to the numerical value 1,
the value 1 is written to the alias "Alarm" which corresponds to the PLC tag named
"Motor1.Alarm" in data block "Data_Block_4" in the CPU.
If a tag name or data block name includes special characters, you must use additional
quotation marks or escape characters as described in the topic Handling tag names that
contain special characters (Page 521).

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13.3.2.8

Creating fragments
STEP 7 converts and stores user-defined Web pages as a control DB and fragment DBs
when you click "Generate blocks" in the CPU Properties for the Web server. You can set up
specific fragments for specific pages or for sections of specific pages. You can identify these
fragments by a name and number with the "Start_Fragment" AWP command. Everything in
the page following the AWP_Start_Fragment command belongs to that fragment until
another AWP_Start_Command is issued or until end of file is reached.

Syntax

Parameters

Text string: name of fragment DB
Fragment names must begin with a letter or underscore and be comprised of
letters, numeric digits, and underscores. The fragment name is a regular
expression of the form:
[a-zA-Z_][a-zA-Z_0-9]*

"manual" or "automatic"
manual: The STEP 7 program must request this fragment and can respond
accordingly. Operation of the fragment must be controlled with STEP 7 and the
control DB variables.
automatic: The Web server processes the fragment automatically.
If you do not specify the type parameter, the default is "automatic".

Integer identification number. If you do not specify the ID parameter, the Web
server assigns a number by default. For manual fragments, set the ID to a low
number. The ID is the means by which the STEP 7 program controls a manual
fragment.

Manual fragments
If you create a manual fragment for a user-defined Web page or portion of a page, then your
STEP 7 program must control when the fragment is sent. The STEP 7 program must set
appropriate parameters in the control DB for a user-defined page under manual control and
then call the WWW instruction with the control DB as modified. For understanding the
structure of the control DB and how to manipulate individual pages and fragments, see the
topic Advanced user-defined Web page control (Page 541).

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13.3.2.9

Importing fragments
You can create a named fragment from a portion of your HTML code and then import that
fragment elsewhere in your set of user-defined Web pages. For example, consider a set of
user-defined Web pages that has a start page and then several other HTML pages
accessible from links on the start page. Suppose each of the separate pages is to display the
company logo on the page. You could implement this by creating a fragment (Page 519) that
loads the image of the company logo. Each individual HTML page could then import this
fragment to display the company logo. You use the AWP Import_Fragment command for this
purpose. The HTML code for the fragment only exists in one fragment, but you can import
this fragment DB as many times as necessary in as many Web pages as you choose.

Syntax

Parameters

Text string: name of the fragment DB to be imported

Example
Excerpt from HTML code that creates a fragment to display an image:

Excerpt from HTML code in another .html file that imports the fragment that displays the logo
image:

Both .html files (the one that creates the fragment and the one that imports it) are in the
folder structure that you define when you configure the user-defined pages in STEP 7
(Page 522).

13.3.2.10

Combining definitions
When declaring variables for use in your user-defined Web pages, you can combine a
variable declaration and an alias for the variable (Page 516). You can also declare multiple
In_Variables in one statement and multiple Out_Variables in one statement.

Examples

<--! AWP_Out_Variable Name='HEADER:Status', Use='"Status"',
Name='HEADER:Location', Use="Location",
Name='COOKIE_VALUE:name', Use="my_cookie" -->

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13.3.2.11

Handling tag names that contain special characters
When specifying variable names in user-defined Web pages, you must take special care if
tag names contain characters that have special meanings.

Reading variables
You use the following syntax to read a variable (Page 511):
:=:
The following rules apply to reading variables:
● For variable names from the PLC tag table, enclose the tag name in double quotation
marks.
● For variable names that are data block tags, enclose the data block name in double
quotation marks. The tag is outside of the quotation marks.
● For variable names that are direct I/O addresses, memory addresses, or alias names, do
not use quotation marks around the read variable.
● For tag names or data block tag names that contain a backslash, precede the backslash
with another backslash.
● If a tag name or data block tag name contains a colon, less than sign, greater than sign,
or ampersand define an alias that has no special characters for the read variable, and
read the variable using the alias. Precede colons in tag names in a Use clause with a
backslash.
Table 13- 1

Examples of Read variables

Data block name

Tag name

n/a

ABC:DEF

n/a

A \B 'C :D

n/a

a
:=special_tag:
:="T\\":

:=another_special_tag:

:=a_less_than_b:
:="Data_block_1".Tag_1:

:=special_tag:
:="DB A' B C D$ E".Tag:

:=my_tag:

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Name and Use clauses
The AWP commands AWP_In_Variable, AWP_Out_Variable, AWP_Enum_Def,
AWP_Enum_Ref, AWP_Start_Fragment and AWP_Import_Fragment have Name clauses.
HTML form commands such as and

The select list is included within a form on the HTML page. When the user clicks the submit
button, the page posts the form, which writes a value of "1" to the Boolean
ManualOverrideEnable in Data_block_1 if the user had selected "Yes", or "0" if the user had
selected "No".

13.3.8.4

Writing user input to the controller
The "Remote Wind Turbine Monitor" HTML page includes several AWP commands for
writing data to the controller (Page 512). The HTML page declares AWP_In_Variables for
Boolean variables so that an admin user can put the wind turbine under manual control and
enable manual override for the turbine speed, yaw override, and/or blade pitch override. The
page also uses AWP_In_Variables to allow an admin user to subsequently set floating-point
values for the turbine speed, yaw, pitch, and braking percentage. The page uses an HTTP
form post command to write the AWP_In_Variables to the controller.
For example, consider the HTML code for manually setting the braking value:

Sample HTML code
The following excerpt from the "Remote Wind Turbine Monitor" HTML page first declares an
AWP_In_Variable for "Data_block_1" that enables the HTML page to write to any tags in the
data block "Data_block_1". The page displays the text "Braking:" in the left cell of a table
row. In the right cell of the table row is the field that accepts user input for the "Braking" tag
of "Data_block_1". This user input value is within an HTML form that uses the HTTP method
"POST" to post the entered text data to the CPU. The page then reads the actual braking
value from the controller and displays it in the data entry field.
An admin user can subsequently use this page to write a braking value to the data block in
the CPU that controls braking.

...

Braking:

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Note
Note that if a user-defined page has a data entry field for a writable data block tag that is a
string data type, the user must enclose the string in single quotation marks when entering
the string value in the field.
Note
Note that if you declare an entire data block in an AWP_In_Variable declaration such as , then every tag within that data block can be
written from the user-defined Web page. Use this when you intend for all of the tags in a data
block to be writable. Otherwise, if you only want specific data block tags to be writable from
the user-defined Web page, declare it specifically with a declaration such as

13.3.8.5

Writing a special variable
The "Remote Wind Turbine Monitor" Web page writes the special variable
SERVER:current_user_id to a PLC tag in the CPU. In this case, the PLC tag value contains
the user ID of whoever is accessing the "Remote Wind Turbine Monitor" Web page.
Currently the admin user has a user ID of 1, so the PLC tag value is set to 1.
The special variable is written to the PLC by the Web page and requires no user interface.

Sample HTML code

13.3.8.6

Reference: HTML listing of remote wind turbine monitor Web page

Wind_turbine.html

Remote Wind Turbine Monitor

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Remote Wind Turbine Monitor: Turbine
#:="Data_block_1".TurbineNumber: :="Data_block_1".Location:

Wind speed:

:="Data_block_1".WindSpeed: km/h

Wind direction:

:="Data_block_1".WindDirection: deg.

Temperature:

:="Data_block_1".Temperature: deg. C

Power output:

:="Data_block_1".PowerOutput: KW

Manual override: :="Data_block_1".ManualOverrideEnable:

Set:

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Turbine speed:

RPM

Yaw override: :="Data_block_1".YawOverride:

Set:

Turbine yaw:

deg.

Pitch override: :="Data_block_1".PitchOverride:

Set:

Blade pitch:

deg.

Braking:

Wind_turbine.css

H2 {
font-family: Arial;
font-weight: bold;
font-size: 14.0pt;
color: #FFFFFF;
margin-top:0pt;
margin-bottom:10pt;
}
P {
font-family: Arial;

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font-weight: bold;
color: #FFFFFF;
font-size: 12.0pt;
margin-top:0pt;
margin-bottom:0pt;
}
TD.Text {
font-family: Arial;
font-weight: bold;
color: #FFFFFF;
font-size: 12.0pt;
margin-top:0pt;
margin-bottom:0pt;
}

13.3.8.7

Configuration in STEP 7 of the example Web page
To include the "Remote Wind Turbine Monitor" HTML page as a user-defined Web page for
the S7-1200, you configure the data about the HTML page in STEP 7 and create data blocks
from the HTML page.
Access the CPU Properties for the S7-1200 that controls the wind turbine, and enter the
configuration information in the User-defined web pages properties of the Web Server:

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Configuration fields
● HTML directory: This field specifies the fully-qualified pathname to the folder where the
default page (home page or start page) is located on the computer. The "..." button allows
you to browse to the folder that you need.
● Default HTML page: This field specifies the filename of the default page or home page of
the HTML application. The "..." button allows you to select the file that you need. For this
example, WindTurbine.html is the default HTML page. The Remote Wind Turbine Monitor
example only consists of a single page, but in other user-defined applications the default
page can call up additional pages from links on the default page. Within the HTML code,
the default page must reference other pages relative to the HTML source folder.
● Application name: This optional field contains the name that the Web browser includes in
the address field when displaying the page. For this example, it is "Remote Wind Turbine
Monitor", but it can be any name.
No other fields require configuration.

Final steps
To use the Remote Wind Turbine Monitor as configured, generate the blocks, program the
WWW instruction (Page 524) with the number of the generated control DB as an input
parameter, download the program blocks, and put the CPU in run mode.
When an operator subsequently accesses the standard Web pages for the S7-1200 that
controls the wind turbine, the "Remote Wind Turbine Monitor" Web page is accessible from
the "User Pages" link on the navigation bar. This page now provides the means to monitor
and control the wind turbine.

13.3.9

Setting up user-defined Web pages in multiple languages
The Web server provides the means for you to provide user-defined Web pages in the
following languages:
● German (de)
● English (en)
● Spanish (es)
● French (fr)
● Italian (it)
● Chinese (zh)
You do this by setting up your HTML pages in a folder structure (Page 538) that corresponds
to the languages and by setting a specific cookie named "siemens_automation_language"
from your pages (Page 538). The Web server responds to this cookie, and switches to the
default page in the corresponding language folder.

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13.3.9.1

Creating the folder structure
To provide user-defined Web pages in multiple languages, you set up a folder structure
under your HTML directory. The two-letter folder names are specific and must be named as
shown below:

de: German
en: English
es: Spanish
fr: French
it: Italian
zh: Chinese
At the same level, you can also include any other folders that your pages need, for example,
folders for images or scripts.
You can include any subset of the language folders. You do not have to include all six
languages. Within the language folders, you create and program your HTML pages in the
appropriate language.

13.3.9.2

Programming the language switch
The Web server performs switching between languages through the use of a cookie named
"siemens_automation_language". This is a cookie defined and set in the HTML pages, and
interpreted by the Web server to display a page in the appropriate language from the
language folder of the same name. The HTML page must include a JavaScript to set this
cookie to one of the pre-defined language identifiers: "de", "en", "es", "fr", "it', or "zh".
For example, if the HTML page sets the cookie to "de", the Web server switches to the "de"
folder and displays the page with the default HTML page name as defined in the STEP 7
configuration (Page 540).

Example
The following example uses a default HTML page named "langswitch.html" in each of the
language folders. Also in the HTML directory is a folder named "script". The script folder
includes a JavaScript file named "lang.js". Each langswitch.html page uses this JavaScript to
set the language cookie, "siemens_automation_language".

HTML for "langswitch.html" in "en" folder
The header of the HTML page sets the language to English, sets the character set to UTF-8,
and sets the path to the JavaScript file lang.js.

Language switching english page

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The body of the file uses a select list for the user to select between German and English.
English ("en") is pre-selected for the language. When the user changes the language, the
page calls the DoLocalLanguageChange() JavaScript function with the value of the selected
option.

HTML for "langswitch.html" in "de" folder
The header for the German langswitch.html page is the same as English, except the
language is set to German.

Sprachumschaltung Deutsche Seite

The HTML in the German page is identical to that of the English page, except that the default
value of the selected language is German ("de").

JavaScript "lang.js" in "script" folder
The function "DoLocalLanguageChange()" is in the lang.js file. This function calls the
"SetLangCookie()" function and then reloads the window that is displaying the HTML page.
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The function "SetLangCookie()" constructs an assignment that assigns the value from the
select list to the "siemens_automation_language" cookie of the document. It also sets the
path to the application so that the switched page, and not the requesting page, receives the
value of the cookie.
Optionally, in the commented section, the page could set an expiration value for the cookie.
function DoLocalLanguageChange(oSelect) {
SetLangCookie(oSelect.value);
top.window.location.reload();
}
function SetLangCookie(value) {
var strval = "siemens_automation_language=";
// This is the cookie by which the Web server
// detects the desired language
// This name is required by the Web server.
strval = strval + value;
strval = strval + "; path=/ ;";
// Set path to the application, since otherwise
// path would be set to the requesting page
// and this page would not get the cookie.
/* OPTIONAL
use expiration if this cookie should live longer
than the current browser session:
var now = new Date();
var endttime = new Date(now.getTime() + expiration);
strval = strval + "; expires=" +
endttime.toGMTString() + ";";
*/
document.cookie = strval;
}

13.3.9.3

Configuring STEP 7 to use a multi-language page structure
The procedure for configuring multi-language user-defined Web pages is similar to the
general process for configuring user-defined Web pages (Page 522). When you have folders
set up for languages, however, you set your HTML directory setting to the folder that
contains the individual language folders. You do not set the HTML directory to be one of the
language folders.
When you select the default HTML page, you navigate into the language folder and select
the HTML page that is to be the start page. When you subsequently generate blocks and
download the blocks to the CPU, the Web server displays the start page in the language
folder that you configured.
For example, if the folder structure shown here was at C:\, the
setting for HTML directory would be C:\html, and if English were to
be the initial page display, you would navigate to en\langswitch.html
for the default HTML page setting.

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13.3.10

Advanced user-defined Web page control
When you generate data blocks for your user-defined Web pages, STEP 7 creates a control
DB that it uses to control display of and interaction with the user-defined pages. STEP 7 also
creates a set of fragment DBs that represent the individual pages. Under normal
circumstances, you do not need to know the structure of the control DB or how to manipulate
it.
If you want to turn a web application on and off, for example, or manipulate individual manual
fragments, you use the control DB tags and the WWW instruction to do so.

Structure of the control DB
The control DB is an extensive data structure, and is accessible when programming your
STEP 7 user program. Only some of the control data block tags are described here.

Commandstate structure
"Commandstate" is a structure that contains global commands and global states for the Web
server.
Global commands in the "Commandstate" structure
The global commands apply to the Web server in general. You can deactivate the Web
server or restart it from the control DB parameters.
Block tag

Data type

Description

init

BOOL

Evaluate the control DB and initialize the
Web application

deactivate

BOOL

Deactivate the Web application

Global states in the Commandstate structure
The global states apply to the Web server in general and contain status information about
the Web application.
Block tag

Data type

Description

initializing

BOOL

Web application is reading control DB

error

BOOL

Web application could not be initialized

deactivating

BOOL

Web application is terminating

deactivated

BOOL

Web application is terminated

initialized

BOOL

Web application is initialized

Request table
The request table is an array of structures containing commands and states that apply to
individual fragment DBs. If you created fragments with the AWP_Start_Fragment (Page 519)
command of type "manual", the STEP 7 user program must control these pages through the
control DB. The request states are read-only and provide information about the current
fragment. You use the request commands to control the current fragment.

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Block tag

Data type

Description

requesttab

ARRAY [ 1 .. 4 ] OF STRUCT

Array of structures for individual
fragment DB control.
The Web server can process up to four
fragments at a time. The array index for
a particular fragment is arbitrary when
the Web server is processing multiple
fragments or fragments from multiple
browser sessions.

Block tag

Data type

Description

page_index

UINT

Number of the current web page

fragment_index

UINT

Number of the current fragment - can be
set to a different fragment

continue

BOOL

Enables current page/fragment for
sending and continues with the next
fragment

repeat

BOOL

Enables current page/fragment for
resending and continues with the same
fragment

abort

BOOL

Close http connection without sending

finish

BOOL

Send this fragment; page is complete do not process any additional fragments

Struct members of requesttab struct

// Request Commands

// Request states

The request states are read-only

idle

BOOL

Nothing to do, but active

waiting

BOOL

Fragment is waiting to be enabled

sending

BOOL

Fragment is sending

aborting

BOOL

User has aborted current request

Operation
Whenever your program makes changes to the control DB, it must call the WWW instruction
with the number of the modified control DB as its parameter. The global commands and
request commands take effect when the STEP 7 user program executes the WWW
instruction (Page 524).
The STEP 7 user program can set the fragment_index explicitly, thus causing the Web
server to process the specified fragment with a request command. Otherwise, the Web
server processes the current fragment for the current page when the WWW instruction
executes.
Possible techniques for using the fragment_index include:

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● Processing the current fragment: Leave fragment_index unchanged and set the continue
command.
● Skip the current fragment: Set fragment_index to 0 and set the continue command.
● Replace current fragment with a different fragment: Set the fragment_index to the new
fragment ID and set the continue command.
To check global states or request states that might be changing, the STEP 7 user program
must call the WWW instruction to evaluate the current values of these states. A typical usage
might be to call the WWW instruction periodically until a specific state occurs.
Note
If the STEP 7 user program sets more than one request command, the WWW instructions
processes only one in this of precedence: abort, finish, repeat, continue. The WWW
instruction clears all of the request commands after processing.

Examples
The following example shows a STEP 7 user program that is checking for a fragment with an
ID of 1 to be in the waiting state, following a prior call to the WWW instruction. It might also
wait for other application-specific conditions to occur. Then it performs whatever processing
is necessary for the fragment, such as setting data block tags, performing calculations, or
other application-specific tasks. Afterwards, it sets the continue flag so that the Web server
will execute this fragment.

When the program calls the WWW instruction with this modified control DB, the user-defined
Web page with this fragment can be displayed from the Web browser.

Note that this is a simplified example; the fragment to check could be in any one of the four
requesttab structs in the array.

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14.1

Status LEDs
The CPU and the I/O modules use LEDs to provide information about either the operational
status of the module or the I/O.

Status LEDs on a CPU
The CPU provides the following status indicators:
● STOP/RUN
– Solid yellow indicates STOP mode
– Solid green indicates RUN mode
– Flashing (alternating green and yellow) indicates that the CPU is in STARTUP mode
● ERROR
– Flashing red indicates an error, such as an internal error in the CPU, a error with the
memory card, or a configuration error (mismatched modules)
– Solid red indicates defective hardware
● MAINT (Maintenance) flashes whenever you insert a memory card. The CPU then
changes to STOP mode. After the CPU has changed to STOP mode, perform one of the
following functions to initiate the evaluation of the memory card:
– Change the CPU to RUN mode
– Perform a memory reset (MRES)
– Power-cycle the CPU
You can also use the LED instruction (Page 256) to determine the status of the LEDs.
Table 14- 1

Status LEDs for a CPU

Description

STOP/RUN
Yellow / Green

ERROR
Red

MAINT
Yellow

Off

Power is off

Off

Startup, self-test, or firmware update

Flashing
(alternating yellow and green)

Off

Stop mode

On (yellow)

Run mode

On (green)

Remove the memory card

On (yellow)

Flashing

Error

On (either yellow or green)

Flashing

Maintenance requested

On (either yellow or green)

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14.1 Status LEDs

Description

STOP/RUN
Yellow / Green

Defective hardware

On (yellow)

LED test or defective CPU firmware

Flashing
(alternating yellow and green)

ERROR
Red

MAINT
Yellow

Off

Flashing

The CPU also provides two LEDs that indicate the status of the PROFINET communications.
Open the bottom terminal block cover to view the PROFINET LEDs.
● Link (green) turns on to indicate a successful connection
● Rx/Tx (yellow) turns on to indicate transmission activity
The CPU and each digital signal module (SM) provide an I/O Channel LED for each of the
digital inputs and outputs. The I/O Channel (green) turns on or off to indicate the state of the
individual input or output.

Status LEDs on an SM
In addition, each digital SM provides a DIAG LED that indicates the status of the module:
● Green indicates that the module is operational
● Red indicates that the module is defective or non-operational
Each analog SM provides an I/O Channel LED for each of the analog inputs and outputs.
● Green indicates that the channel has been configured and is active
● Red indicates an error condition of the individual analog input or output
In addition, each analog SM provides a DIAG LED that indicates the status of the module:
● Green indicates that the module is operational
● Red indicates that the module is defective or non-operational
The SM detects the presence or absence of power to the module (field-side power, if
required).
Table 14- 2

Status LEDs for a signal module (SM)

Description
Field-side power is off
Not configured or update in progress
Module configured with no errors

DIAG

I/O Channel

(Red / Green)

Flashing red

Flashing green

Off

On (green)

Flashing red

I/O error (with diagnostics enabled)

Flashing red

I/O error (with diagnostics disabled)

On (green)

Error condition

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14.2 Going online and connecting to a CPU

14.2

Going online and connecting to a CPU
An online connection between the programming device and CPU is required for loading
programs and project engineering data as well as for activities such as the following:
● Testing user programs
● Displaying and changing the operating mode of the CPU (Page 550)
● Displaying and setting the date and time of day of the CPU (Page 549)
● Displaying the module information
● Comparing and synchronizing (Page 551) offline to online program blocks
● Uploading and downloading program blocks
● Displaying diagnostics and the diagnostics buffer (Page 551)
● Using a watch table (Page 555) to test the user program by monitoring and modifying
values
● Using a force table to force values in the CPU (Page 558)
To establish an online connection to a configured CPU, click
the CPU from the Project Navigation tree and click the "Go
online" button from the Project View:
If this is the first time to go
online with this CPU, you
must select the type of PG/PC
interface and the specific
PG/PC interface from the Go
Online dialog before
establishing an online
connection to a CPU found on
that interface.

Your programming device is now connected to the CPU. The orange color frames indicate
an online connection. You can now use the Online & diagnostics tools from the Project tree
and the Online tools task card.

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14.3 Assigning a name to a PROFINET IO device online

14.3

Assigning a name to a PROFINET IO device online
The devices on your PROFINET network must have an assigned name before you can
connect with the CPU. Use the "Devices & networks" editor to assign names to your
PROFINET devices if the devices have not already been assigned a name or if the name of
the device is to be changed.
For each PROFINET IO device, you must assign the same name to that device in both the
STEP 7 project and, using the "Online & diagnostics" tool, to the PROFINET IO device
configuration memory (for example, an ET200 S interface module configuration memory). If
a name is missing or does not match in either location, the PROFINET IO data exchange
mode will not run.
1. In the "Devices & networks"
editor, right-click on the
required PROFINET IO
device, and select "Online &
diagnostics".

2. In the "Online &
diagnostics" dialog, make the
following menu selections:
 "Functions"
 "Assign name"
Click the "Accessible devices
in the network" icon to display
all of the PROFINET IO
devices on the network.

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14.4 Setting the IP address and time of day
3. In the list that is displayed,
click the required PROFINET
IO device, and click the
"Assign name" button to write
the name to the PROFINET IO
device configuration memory.

14.4

Setting the IP address and time of day
You can set the IP address and time of day in the online CPU. After accessing "Online &
diagnostics" from the Project tree for an online CPU, you can display or change the IP
address. You can also display or set the time and date parameters of the online CPU.
Refer to the section on the IP address for more information.

Note
This feature is available only for a CPU that either has only a MAC address (has not yet
been assigned an IP address) or has been reset to factory settings.

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14.5 CPU operator panel for the online CPU

14.5

CPU operator panel for the online CPU
The "CPU operator panel" displays the operating mode (STOP or
RUN) of the online CPU. The panel also shows whether the CPU has
an error or if values are being forced.

Use the CPU operating panel of the Online Tools task card to change the operating mode of
an online CPU. The Online Tools task card is accessible whenever the CPU is online.

14.6

Monitoring the cycle time and memory usage
You can monitor the cycle
time and memory usage of
an online CPU.
After connecting to the
online CPU, open the Online
tools task card to view the
following measurements:
 Cycle time
 Memory usage

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14.7 Displaying diagnostic events in the CPU

14.7

Displaying diagnostic events in the CPU
Use the diagnostics buffer to review the recent activity in the CPU. The diagnostics buffer is
accessible from "Online & Diagnostics" for an online CPU in the Project tree. It contains the
following entries:
● Diagnostic events
● Changes in the CPU operating mode (transitions to STOP or RUN mode)
The first entry contains the latest event.
Each entry in the diagnostic buffer
contains the date and time the event
was logged, and a description.
The maximum number of entries is
dependent on the CPU. A maximum of
50 entries is supported.
Only the 10 most recent events in the
diagnostic buffer are stored
permanently. Resetting the CPU to the
factory settings resets the diagnostic
buffer by deleting the entries.

You can also use the GET_DIAG instruction (Page 259) to collect the diagnostic information.

14.8

Comparing and synchronizing offline and online CPUs
You can compare the code blocks in an online CPU with the code blocks in your project. If
the code blocks of your project do not match the code blocks of the online CPU, the
"Compare" editor allows you to synchronize your project with the online CPU by either
downloading the code blocks of your project or uploading from the online CPU.
Synchronization is another way to upload a project from an online CPU.
Select the CPU in your project.
Use the "Compare Offline/online" command to open the
"Compare" editor. (Access the command either from the "Tools"
menu or by right-clicking the CPU in your project.)

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Click the "Action" icon to select whether
to upload, download or take no action.
Click the "Synchronize" button to load
the code blocks.
Click the "detailed comparison" button to show
the code blocks side-by-side.
The detailed comparison highlights the
differences between the code blocks of online
CPU and the code blocks of the CPU in your
project.

14.9

Monitoring and modifying values in the CPU
STEP 7 provides online tools for monitoring the CPU:
● You can display or monitor the current values of the tags. The monitoring function does
not change the program sequence. It presents you with information about the program
sequence and the data of the program in the CPU.
● You can also use other functions to control the sequence and the data of the user
program:
– You can modify the value for the tags in the online CPU to see how the user program
responds.
– You can force a peripheral output (such as Q0.1:P or "Start":P) to a specific value.
– You can enable outputs in STOP mode.
Note
Always exercise caution when using control functions. These functions can seriously
influence the execution of the user/system program.

Table 14- 3

Online capabilities of the STEP 7 editors

Editor

Monitor

Modify

Force

Watch table

Yes

Force table

Yes

Program editor

Yes

Tag table

Yes

DB editor

Yes

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14.9 Monitoring and modifying values in the CPU

14.9.1

Going online to monitor the values in the CPU
To monitor the tags, you must have an online connection to the CPU. Simply click the "Go
online" button in the toolbar.

When you have connected to the CPU, STEP 7 turns the headers of
the work areas orange.
The project tree displays a comparison of the offline project and the
online CPU. A green circle means that the CPU and the project are
synchronized, meaning that both have the same configuration and
user program.
Tag tables show the tags. Watch tables can also show the tags, as
well as direct addresses.

To monitor the execution of the user program and to display the values of the tags,
click the "Monitor all" button in the toolbar.

The "Monitor value" field shows the value for each tag.

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14.9.2

Displaying status in the program editor
You can monitor the status of the tags in the LAD and FBD program editors. Use the editor
bar to display the LAD editor. The editor bar allows you to change the view between the
open editors without having to open or close the editors.
In the toolbar of the program editor, click the "Monitoring on/off" button to display the status
of your user program.

The network in the program editor displays power flow in green.
You can also right-click on the instruction or parameter to modify the value for the instruction.

14.9.3

Capturing the online values of a DB to reset the start values
You can capture the current values being monitored in an online CPU to become the start
values for a global DB.
● You must have an online connection to the CPU.
● The CPU must be in RUN mode.
● You must have opened the DB in STEP 7.
Use the "Show a snapshot of the monitored values" button to capture the current
values of the selected tags in the DB. You can then copy these values into the "Start
value" column of the DB.
1. In the DB editor, click the "Monitor all tags" button. The "Monitor value" column displays
the current data values.
2. Click the "Show a snapshot of the monitored values" button to display the current values
in the "Snapshot" column.
3. Click the "Monitor all" button to stop monitoring the data in the CPU.
4. Copy a value in the "Snapshot" column for a tag.
– Select a value to be copied.
– Right-click the selected value to display the context menu.
– Select the "Copy" command.
5. Paste the copied value into the corresponding "Start value" column for the tag. (Rightclick the cell and select "Paste" from the context menu.)

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6. Save the project to configure the copied values as the new start values for the DB.
7. Compile and download the DB to the CPU. The DB uses the new start values after the
CPU goes to RUN mode.
Note
The values that are shown in the "Monitor value" column are always copied from the
CPU. STEP 7 does not check whether all values come from the same scan cycle of the
CPU.

14.9.4

Using a watch table to monitor and modify values in the CPU
A watch table allows you to perform monitoring and control functions on data points as the
CPU executes your program. These data points can be process image (I or Q), M, DB or
physical inputs (I_:P), depending on the monitor or control function. You cannot accurately
monitor the physical outputs (Q_:P) because the monitor function can only display the last
value written from Q memory and does not read the actual value from the physical outputs.
The monitoring function does not change the program sequence. It presents you with
information about the program sequence and the data of the program in the CPU.
Control functions enable the user to control the sequence and the data of the program.
Caution must be exercised when using control functions. These functions can seriously
influence the execution of the user/system program. The three control functions are Modify,
Force and Enable Outputs in STOP.
With the watch table, you can perform the following online functions:
● Monitoring the status of the tags
● Modifying values for the individual tags
You select when to monitor or modify the tag:
● Beginning of scan cycle: Reads or writes the value at the beginning of the scan cycle
● End of scan cycle: Reads or writes the value at the end of the scan cycle
● Switch to stop
To create a watch table:
1. Double-click "Add new watch table" to open a new
watch table.
2. Enter the tag name to add a tag to the watch table.
The following options are available for monitoring tags:
 Monitor all: This command starts the monitoring of
the visible tags in the active watch table.
 Monitor now: This command starts the monitoring
of the visible tags in the active watch table. The
watch table monitors the tags immediately and
once only.

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14.9 Monitoring and modifying values in the CPU
The following options are available for modifying tags:
● "Modify to 0" sets the value of a selected address to "0".
● "Modify to 1" sets the value of a selected address to "1".
● "Modify now" immediately changes the value for the selected addresses for one scan
cycle.
● "Modify with trigger" changes the values for the selected addresses.
This function does not provide feedback to indicate that the selected addresses were
actually modified. If feedback of the change is required, use the "Modify now" function.
● "Enable peripheral outputs" disables the command output disable and is available only
when the CPU is in STOP mode.
To monitor the tags, you must have an online connection to the CPU.

The various functions can be selected using the buttons at the top of the watch table.
Enter the tag name to monitor and select a display format from the dropdown selection. With
an online connection to the CPU, clicking the "Monitor" button displays the actual value of
the data point in the "Monitor value" field.

14.9.4.1

Using a trigger when monitoring or modifying PLC tags
Triggering determines at what point in the scan cycle the selected address will be monitored
or modified.
Table 14- 4

Types of triggers

Trigger

Description

Permanent

Continuously collects the data

At scan cycle start

Permanent: Continuously collects the data at the start of the scan cycle, after
the CPU reads the inputs
Once: Collects the data at the start of the scan cycle, after the CPU reads the
inputs

At scan cycle end

Permanent: Continuously collects the data at the end of the scan cycle, before
the CPU writes the outputs
Once: Collects the data once at the end of the scan cycle, before the CPU
writes the outputs

At transition to
STOP

Permanent: Continuously collects data when the CPU transitions to STOP
Once: Collects the data once after the CPU transitions to STOP

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14.9 Monitoring and modifying values in the CPU
For modifying a PLC tag at a given trigger, select either the start or the end of cycle.
● Modifying an output: The best trigger event for modifying an output is at the end of the
scan cycle, immediately before the CPU writes the outputs.
Monitor the value of the outputs at the beginning of the scan cycle to determine what
value is written to the physical outputs. Also, monitor the outputs before the CPU writes
the values to the physical outputs in order to check program logic and to compare to the
actual I/O behavior.
● Modifying an input: The best trigger event for modifying an input is at the start of the
cycle, immediately after the CPU reads the inputs and before the user program uses the
input values.
If you are modifying inputs the start of the scan cycle, you should also monitor the value
of the inputs at the end of the scan cycle to ensure that the value of the input at the end
the scan cycle has not changed from the start of the scan cycle. If there is a difference in
the values, your user program may be writing to an input in error.
To diagnose why the CPU might have gone to STOP, use the "Transition to STOP" trigger to
capture the last process values.

14.9.4.2

Enabling outputs in STOP mode
The watch table allows you to write to the outputs when the CPU is in STOP mode. This
functionality allows you to check the wiring of the outputs and verify that the wire connected
to an output pin initiates a high or low signal to the terminal of the process device to which it
is connected.
WARNING
Even though the CPU is in STOP mode, enabling a physical output can activate the
process point to which it is connected.
You can change the state of the outputs in STOP mode when the outputs are enabled. If the
outputs are disabled, you cannot modify the outputs in STOP mode.
● To enable the modification of the outputs in STOP, select the "Enable peripheral outputs"
option of the "Modify" command of the "Online" menu, or by right-clicking the row of the
Watch table.
You cannot enable outputs in STOP mode if you have configured distributed I/O,. An
error is returned when you try to do this.
● Setting the CPU to RUN mode disables "Enable peripheral outputs" option.
● If any inputs or outputs are forced, the CPU is not allowed to enable outputs while in
STOP mode. The force function must first be cancelled.

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14.9 Monitoring and modifying values in the CPU

14.9.5

Forcing values in the CPU

14.9.5.1

Using the force table
A force table provides a "force" function that overwrites the value for an input or output point
to a specified value for the peripheral input or peripheral output address. The CPU applies
this forced value to the input process image prior to the execution of the user program and to
the output process image before the outputs are written to the modules.

Note
The force values are stored in the CPU and not in the force table.
You cannot force an input (or "I" address) or an output (or "Q" address). However, you can
force a peripheral input or peripheral output. The force table automatically appends a ":P" to
the address (for example: "On":P or "Run":P).

In the "Force value" cell, enter the value for the input or output to be forced. You can then
use the check box in the "Force" column to enable forcing of the input or output.
Use the "Start or replace forcing" button to force the value of the tags in the force
table. Click the "Stop forcing" button to reset the value of the tags.
In the force table, you can monitor the status of the forced value for an input. However, you
cannot monitor the forced value of an output.
You can also view the status of the forced value in the program editor.

NOTICE
When an input or output is forced in a force table, the force actions become part of the
project configuration. If you close STEP 7, the forced elements remain active in the CPU
program until they are cleared. To clear these forced elements, you must use STEP 7 to
connect with the online CPU and then use the force table to turn off or stop the force
function for those elements.

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14.9 Monitoring and modifying values in the CPU

14.9.5.2

Operation of the Force function
The CPU allows you to force input and output point(s) by specifying the physical input or
output address (I_:P or Q_:P) in the watch table and then starting the force function.
In the program, reads of physical inputs are overwritten by the forced value. The program
uses the forced value in processing. When the program writes a physical output, the output
value is overwritten by the force value. The forced value appears at the physical output and
is used by the process.
When an input or output is forced in the force table, the force actions become part of the
user program. Even though the programming software has been closed, the force selections
remain active in the operating CPU program until they are cleared by going online with the
programming software and stopping the force function. Programs with forced points loaded
on another CPU from a memory card will continue to force the points selected in the
program.
If the CPU is executing the user program from a write-protected memory card, you cannot
initiate or change the forcing of I/O from a watch table because you cannot override the
values in the write-protected user program. Any attempt to force the write-protected values
generates an error. If you use a memory card to transfer a user program, any forced
elements on that memory card will be transferred to the CPU.
Note
Digital I/O points assigned to HSC, PWM, and PTO cannot be forced
The digital I/O points used by the high-speed counter (HSC), pulse-width modulation (PWM),
and pulse-train output (PTO) devices are assigned during device configuration. When digital
I/O point addresses are assigned to these devices, the values of the assigned I/O point
addresses cannot be modified by the force function of the watch table.

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ུ

(

཰

)

Startup

ཱ

ི

ཱི

RUN

The clearing of the I memory area is not
affected by the Force function.

①

The initialization of the outputs values is
not affected by the Force function.

②

During the execution of the startup OBs,
the CPU applies the force value when
the user program accesses the physical
input.

③

The storing of interrupt events into the
queue is not affected.

④

The enabling of the writing to the
outputs is not affected.

⑤

While writing Q memory to the physical
outputs, the CPU applies the force value as
the outputs are updated.
When reading the physical inputs, the CPU
applies the force values just prior to copying
the inputs into I memory.
During the execution of the user program
(program cycle OBs), the CPU applies the
force value when the user program accesses
the physical input or writes the physical
output.
Handling of communication requests and selftest diagnostics are not affected by the Force
function.
The processing of interrupts during any part of
the scan cycle is not affected.

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A.1

General Technical Specifications

Standards compliance
The S7-1200 automation system complies with the following standards and test
specifications. The test criteria for the S7-1200 automation system are based on these
standards and test specifications.

CE approval
The S7-1200 Automation System satisfies requirements and safety related objectives
according to the EC directives listed below, and conforms to the harmonized European
standards (EN) for the programmable controllers listed in the Official Journals of the
European Community.
● EC Directive 2006/95/EC (Low Voltage Directive) "Electrical Equipment Designed for Use
within Certain Voltage Limits"
– EN 61131-2:2007 Programmable controllers - Equipment requirements and tests
● EC Directive 2004/108/EC (EMC Directive) "Electromagnetic Compatibility"
– Emission standard
EN 61000-6-4:2007: Industrial Environment
– Immunity standard
EN 61000-6-2:2005: Industrial Environment
● EC Directive 94/9/EC (ATEX) "Equipment and Protective Systems Intended for Use in
Potentially Explosive Atmosphere"
– EN 60079-15:2005: Type of Protection 'n'
The CE Declaration of Conformity is held on file available to competent authorities at:
Siemens AG
IA AS RD ST PLC Amberg
Werner-von-Siemens-Str. 50
D92224 Amberg
Germany

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A.1 General Technical Specifications

cULus approval
Underwriters Laboratories Inc. complying with:
● Underwriters Laboratories, Inc.: UL 508 Listed (Industrial Control Equipment)
● Canadian Standards Association: CSA C22.2 Number 142 (Process Control Equipment)
NOTICE
The SIMATIC S7-1200 series meets the CSA standard.
The cULus logo indicates that the S7-1200 has been examined and certified by
Underwriters Laboratories (UL) to standards UL 508 and CSA 22.2 No. 142.

FM approval
Factory Mutual Research (FM)
Approval Standard Class Number 3600 and 3611
Approved for use in:
Class I, Division 2, Gas Group A, B, C, D, Temperature Class T4A Ta = 40° C
Class I, Zone 2, IIC, Temperature Class T4 Ta = 40° C
Canadian Class I, Zone 2 Installation per CEC 18-150
Note
The SM 1223 DI 8 x 120/230 VAC, DQ 8 x Relay (6ES7 223-1QH30-0XB0) signal module is
approved for use in Class 1, Division 2, Gas Group A, B, C, D, Temperature
Class T4 Ta = 40° C.

ATEX approval
EN 60079-0:2006: Explosive Atmospheres - General Requirements
EN 60079-15:2005: Electrical Apparatus for potentially explosive atmospheres;
Type of protection 'n'
II 3 G Ex nA II T4
The following special conditions for safe use of the S7-1200 must be followed:
● Install modules in a suitable enclosure providing a minimum degree of protection of IP54
according to EN 60529 and take into account the environmental conditions under which
the equipment will be used.
● When the temperature under rated conditions exceeds 70° C at the cable entry point, or
80° C at the branching point of the conductors, the temperature specification of the
selected cable should be in compliance with the actual measured temperature.
● Provisions should be made to prevent the rated voltage from being exceeded by transient
disturbances of more than 40%.

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C-Tick approval
The S7-1200 automation system satisfies requirements of standards to AS/NZS 2064
(Class A).

Maritime approval
The S7-1200 products are periodically submitted for special agency approvals related to
specific markets and applications. Consult your local Siemens representative if you need
additional information related to the latest listing of exact approvals by part number.
Classification societies:
● ABS (American Bureau of Shipping)
● BV (Bureau Veritas)
● DNV (Det Norske Veritas)
● GL (Germanischer Lloyd)
● LRS (Lloyds Register of Shipping)
● Class NK (Nippon Kaiji Kyokai)
Note
The CM 1242-5 (PROFIBUS Slave module), the CM 1243-5 (PROFIBUS Master
module), and the CP 1242-7 (GPRS module) do not have Maritime approval.

Industrial environments
The S7-1200 automation system is designed for use in industrial environments.
Table A- 1

Industrial environments

Application field

Noise emission requirements

Noise immunity requirements

Industrial

EN 61000-6-4:2007

EN 61000-6-2:2005

Electromagnetic compatibility
Electromagnetic Compatibility (EMC) is the ability of an electrical device to operate as
intended in an electromagnetic environment and to operate without emitting levels of
electromagnetic interference (EMI) that may disturb other electrical devices in the vicinity.
Table A- 2

Immunity per EN 61000-6-2

Electromagnetic compatibility - Immunity per EN 61000-6-2
EN 61000-4-2
Electrostatic discharge

8 kV air discharge to all surfaces
6 kV contact discharge to exposed conductive surfaces

EN 61000-4-3
Radiated, radio-frequency,
electromagnetic field immunity test

80 to 1000 MHz, 10 V/m, 80% AM at 1 kHz
1.4 to 2.0 GHz, 3 V/m, 80% AM a 1 kHz
2.0 to 2.7 GHz, 1 V/m, 80% AM at 1 kHz

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Electromagnetic compatibility - Immunity per EN 61000-6-2
EN 61000-4-4
Fast transient bursts

2 kV, 5 kHz with coupling network to AC and DC system power
2 kV, 5 kHz with coupling clamp to I/O

EN 6100-4-5
Surge immunity

AC systems - 2 kV common mode, 1kV differential mode
DC systems - 2 kV common mode, 1kV differential mode
For DC systems (I/O signals, DC power systems) external protection is
required.

EN 61000-4-6
Conducted disturbances

150 kHz to 80 MHz, 10 V RMS, 80% AM at 1kHz

EN 61000-4-11
Voltage dips

AC systems
0% for 1 cycle, 40% for 12 cycles and 70% for 30 cycles at 60 Hz

Table A- 3

Conducted and radiated emissions per EN 61000-6-4

Electromagnetic compatibility - Conducted and radiated emissions per EN 61000-6-4
Conducted Emissions

0.15 MHz to 0.5 MHz

<79dB (μV) quasi-peak; <66 dB (μV) average

EN 55011, Class A, Group 1

0.5 MHz to 5 MHz

<73dB (μV) quasi-peak; <60 dB (μV) average

5 MHz to 30 MHz

<73dB (μV) quasi-peak; <60 dB (μV) average

Radiated Emissions

30 MHz to 230 MHz

<40dB (μV/m) quasi-peak; measured at 10m

EN 55011, Class A, Group 1

230 MHz to 1 GHz

<47dB (μV/m) quasi-peak; measured at 10m

Environmental conditions
Table A- 4

Transport and storage

Environmental conditions - Transport and storage
EN 60068-2-2, Test Bb, Dry heat and
EN 60068-2-1, Test Ab, Cold

-40° C to +70° C

EN 60068-2-30, Test Db, Damp heat

25° C to 55° C, 95% humidity

EN 60068-2-14, Test Na, temperature shock

-40° C to +70° C, dwell time 3 hours, 5 cycles

EN 60068-2-32, Free fall

0.3 m, 5 times, product packaging

Atmospheric pressure

1080 to 660h Pa (corresponding to an altitude of -1000 to 3500m)

Table A- 5

Operating conditions

Environmental conditions - Operating
Ambient temperature range
(Inlet Air 25 mm below unit)

0° C to 55° C horizontal mounting
0° C to 45° C vertical mounting
95% non-condensing humidity

Atmospheric pressure

1080 to 795 hPa (corresponding to an altitude of -1000 to 2000m)

Concentration of contaminants

S02: < 0.5 ppm; H2S: < 0.1 ppm; RH < 60% non-condensing

EN 60068-2-14, Test Nb, temperature change

5° C to 55° C, 3° C/minute

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Environmental conditions - Operating
EN 60068-2-27 Mechanical shock

15 G, 11 ms pulse, 6 shocks in each of 3 axis

EN 60068-2-6 Sinusoidal vibration

DIN rail mount: 3.5 mm from 5-9 Hz, 1G from 9 - 150 Hz
Panel Mount: 7.0 mm from 5-9 Hz, 2G from 9 to 150 Hz
10 sweeps each axis, 1 octave per minute

Table A- 6

High potential isolation test

High potential isolation test
24 V/5 V nominal circuits
115/230 V circuits to ground
115/230 V circuits to 115/230 V circuits
115 V/230V circuits to 24 V/5 V circuits

520 VDC (type test of optical isolation boundaries)
1,500 VAC routine test/1950 VDC type test
1,500 VAC routine test/1950 VDC type test
1,500 VAC routine test/3250 VDC type test

Protection class
● Protection Class II according to EN 61131-2 (Protective conductor not required)

Degree of protection
● IP20 Mechanical Protection, EN 60529
● Protects against finger contact with high voltage as tested by standard probe. External
protection required for dust, dirt, water and foreign objects of < 12.5mm in diameter.

Rated voltages
Table A- 7

Rated voltages

Rated voltage

Tolerance

24 VDC

20.4 VDC to 28.8 VDC

120/230 VAC

85 VAC to 264 VAC, 47 to 63 Hz

NOTICE
When a mechanical contact turns on output power to the S7-1200 CPU, or any digital
signal module, it sends a "1" signal to the digital outputs for approximately 50
microseconds. This could cause unexpected machine or process operation which could
result in death or serious injury to personnel and/or damage to equipment. You must plan
for this, especially if you are using devices which respond to short duration pulses.

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A.2 CPU 1211C

Relay electrical service life
The typical performance data supplied by relay vendors is shown below. Actual performance
may vary depending upon your specific application. An external protection circuit that is
adapted to the load will enhance the service life of the contacts.

① Service life (x 103 operations)
② 250 VAC resistive load

30 VDC resistive load

③ 250 VAC inductive load (p.f=0.4)

30 VDC inductive load (L/R=7ms)

④ Rated Operating Current (A)

A.2

CPU 1211C

A.2.1

General specifications and features

Table A- 8

General specifications

Technical data

CPU 1211C
AC/DC/Relay

CPU 1211C
DC/DC/Relay

CPU 1211C
DC/DC/DC

Order number

6ES7 211-1BD30-0XB0

6ES7 211-1HD30-0XB0

6ES7 211-1AD30-0XB0

Dimensions W x H x D (mm)

90 x 100 x 75

Weight

420 grams

380 grams

370 grams

Power dissipation

10 W

Current available (CM bus)

750 mA max. (5 VDC)

Current available (24 VDC)

300 mA max. (sensor
power)

4 mA/input used

Digital input current consumption 4 mA/input used
(24VDC)

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A.2 CPU 1211C
Table A- 9

CPU features

Technical data
User

memory1

Description
Work

25 Kbytes

Load

1 Mbytes

Retentive

2 Kbytes

On-board digital I/O

6 inputs/4 outputs

On-board analog I/O

2 inputs

Process image size

1024 bytes of inputs (I) /1024 bytes of outputs (Q)

Bit memory (M)

4096 bytes

Signal modules expansion

none

Signal board expansion

1 SB max.

Communication module expansion

3 CMs max.

High-speed counters

3 total


Single phase: 3 at 100 kHz



Quadrature phase: 3 at 80 kHz

Pulse outputs 2

Pulse catch inputs

Time delay / cyclic interrupts

4 total with 1 ms resolution

Edge interrupts

6 rising and 6 falling (10 and 10 with optional signal board)

Memory card

SIMATIC Memory Card (optional)

Real time clock accuracy

+/- 60 seconds/month

Real time clock retention time

10 days typ./6 days min. at 40°C (maintenance-free Super Capacitor)

The size of the user program, data, and configuration is limited by the available load memory and work memory in the
CPU. There is no specific limit to the number of OB, FC, FB and DB blocks supported or to the size of a particular block;
the only limit is due to overall memory size.

For CPU models with relay outputs, you must install a digital signal board (SB) to use the pulse outputs.

Table A- 10

Performance

Type of instruction

Execution speed

Boolean

0.1 μs/instruction

Move Word

12 μs/instruction

Real math

18 μs/instruction

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A.2 CPU 1211C
Table A- 11

Blocks, timers and counters supported by S7-1200

Element

Description

Blocks

Type

OB, FB, FC, DB

Size

25 Kbytes (CPU 1211C and CPU 1212C)
50 Kbytes (CPU 1214C)

OBs

Timers

Counters

Quantity

Up to 1024 blocks total (OBs + FBs + FCs + DBs)

Address range for FBs, FCs,
and DBs

1 to 65535 (such as FB 1 to FB 65535)

Nesting depth

16 from the program cycle or start up OB; 4 from the time delay
interrupt, time-of-day interrupt, cyclic interrupt, hardware interrupt,
time error interrupt, or diagnostic error interrupt OB

Monitoring

Status of 2 code blocks can be monitored simultaneously

Program cycle

Multiple: OB 1, OB 200 to OB 65535

Startup

Multiple: OB 100, OB 200 to OB 65535

Time-delay interrupts and
cyclic interrupts

41 (1 per event): OB 200 to OB 65535

Hardware interrupts (edges
and HSC)

50 (1 per event): OB 200 to OB 65535

Time error interrupts

1: OB 80

Diagnostic error interrupts

1: OB 82

Type

IEC

Quantity

Limited only by memory size

Storage

Structure in DB, 16 bytes per timer

Type

IEC

Quantity

Limited only by memory size

Storage

Structure in DB, size dependent upon count type


SInt, USInt: 3 bytes



Int, UInt: 6 bytes



DInt, UDInt: 12 bytes

Table A- 12

Communication

Technical data

Description

Number of ports

Type

Ethernet

Connections



4 for HMI



3 for programming device



8 for Ethernet instructions in the user program



8 for CPU-to-CPU

Data rates

10/100 Mb/s

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A.2 CPU 1211C

Technical data

Description

Isolation (external signal to PLC logic)

Transformer isolated, 1500 VDC

Cable type

CAT5e shielded

Table A- 13

Power supply

Technical data

CPU 1211C
AC/DC/Relay

CPU 1211C
DC/DC/Relay

CPU 1211C
DC/DC/DC

Voltage range

85 to 264 VAC

20.4 to 28.8 VDC

Line frequency

47 to 63 Hz

Input
current

CPU only at max. load

60 mA at 120 VAC
30 mA at 240 VAC

300 mA at 24 VDC

CPU with all expansion
accessories at max. load

180 mA at 120 VAC
90 mA at 240 VAC

900 mA at 24 VDC

Inrush current (max.)

20 A at 264 VAC

12 A at 28.8 VDC

Isolation (input power to logic)

1500 VAC

Not isolated

Ground leakage, AC line to functional
earth

0.5 mA max.

Hold up time (loss of power)

20 ms at 120 VAC
80 ms at 240 VAC

10 ms at 24 VDC

Internal fuse, not user replaceable

3 A, 250 V, slow blow

Technical data

CPU 1211C
AC/DC/Relay

CPU 1211C
DC/DC/Relay

CPU 1211C
DC/DC/DC

Voltage range

20.4 to 28.8 VDC

L+ minus 4 VDC min.

Output current rating (max.)

300 mA (short circuit
protected)

Maximum ripple noise (<10 MHz)

< 1 V peak to peak

Same as input line

Isolation (CPU logic to sensor power)

Not isolated

Table A- 14

Sensor power

A.2.2
Table A- 15

Digital inputs and outputs
Digital inputs

Technical data

CPU 1211C AC/DC/Relay, DC/DC/Relay, and DC/DC/DC

Number of inputs

Type

Sink/Source (IEC Type 1 sink)

Rated voltage

24 VDC at 4 mA, nominal

Continuous permissible voltage

30 VDC, max.

Surge voltage

35 VDC for 0.5 sec.

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A.2 CPU 1211C

Technical data

CPU 1211C AC/DC/Relay, DC/DC/Relay, and DC/DC/DC

Logic 1 signal (min.)

15 VDC at 2.5 mA

Logic 0 signal (max.)

5 VDC at 1 mA

Isolation (field side to logic)

500 VAC for 1 minute

Isolation groups

Filter times

0.2, 0.4, 0.8, 1.6, 3.2, 6.4, and 12.8 ms (selectable in groups of 4)

HSC clock input rates (max.)
(Logic 1 Level = 15 to 26 VDC)

Single phase: 100 KHz

Number of inputs on simultaneously

Cable length (meters)

500 m shielded, 300 m unshielded, 50 m shielded for HSC inputs

Table A- 16

Quadrature phase: 80 KHz

Digital outputs

Technical data

CPU 1211C AC/DC/Relay and
DC/DC/Relay

CPU 1211C
DC/DC/DC

Number of outputs

Type

Relay, dry contact

Solid state - MOSFET (sourcing)

Voltage range

5 to 30 VDC or 5 to 250 VAC

20.4 to 28.8 VDC

Logic 1 signal at max. current

20 VDC min.

Logic 0 signal with 10 KΩ load

0.1 VDC max.

Current (max.)

2.0 A

0.5 A

Lamp load

30 W DC / 200 W AC

ON state resistance

0.2 Ω max. when new

0.6 Ω max.

Leakage current per point

10 μA max.

Surge current

7 A with contacts closed

8 A for 100 ms max.

Overload protection

Isolation (field side to logic)

1500 VAC for 1 minute
(coil to contact)

500 VAC for 1 minute

None (coil to logic)
Isolation resistance

100 MΩ min. when new

Isolation between open contacts

750 VAC for 1 minute

Isolation groups

Inductive clamp voltage

L+ minus 48 VDC, 1 W dissipation

Maximum relay switching frequency

1 Hz

Switching delay (Qa.0 to Qa.3)

10 ms max.

1.0 μs max., off to on
3.0 μs max., on to off

Pulse Train Output rate
(Qa.0 and Qa.2)

Not recommended 1

100 KHz max.,
2 Hz min.2

Lifetime mechanical (no load)

10,000,000 open/close cycles

Lifetime contacts at rated load

100,000 open/close cycles

Behavior on RUN to STOP

Last value or substitute value
(default value 0)

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A.2 CPU 1211C

Technical data

CPU 1211C AC/DC/Relay and
DC/DC/Relay

CPU 1211C
DC/DC/DC

Number of outputs on simultaneously

Cable length (meters)

500 m shielded,
150 m unshielded

For CPU models with relay outputs, you must install a digital signal board (SB) to use the pulse outputs.

Depending on your pulse receiver and cable, an additional load resistor (at least 10% of rated current) may improve
pulse signal quality and noise immunity.

A.2.3
Table A- 17

Analog inputs
Analog inputs

Technical data

Description

Number of inputs

Type

Voltage (single-ended)

Range

0 to 10 V

Full-scale range (data word)

0 to 27648

Overshoot range (data word)

27,649 to 32,511
See the table for measurement ranges of the analog inputs for voltage
(Page 572).

Overflow (data word)

32,512 to 32,767

Resolution

10 bits

Maximum withstand voltage

35 VDC

Smoothing

None, Weak, Medium, or Strong
See the table for step response (ms) for the analog inputs of the CPU
(Page 572).

Noise rejection

10, 50, or 60 Hz

Impedance

≥100 KΩ

Isolation (field side to logic)

None

Accuracy (25°C / 0 to 55°C)

3.0% / 3.5% of full-scale

Common mode rejection

40 dB, DC to 60 Hz

Operational signal range

Signal plus common mode voltage must be less than +12 V and greater
than -12 V

Cable length (meters)

100 m, shielded twisted pair

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Technical specifications
A.2 CPU 1211C

A.2.3.1

Step response of the built-in analog inputs of the CPU

Table A- 18

Step Response (ms), 0V to 10V measured at 95%

Smoothing selection (sample averaging)

Rejection frequency (Integration time)
60 Hz

50 Hz

10 Hz

None (1 cycle): No averaging

63 ms

65 ms

130 ms

Weak (4 cycles): 4 samples

84 ms

93 ms

340 ms

Medium (16 cycles): 16 samples

221 ms

258 ms

1210 ms

Strong (32 cycles): 32 samples

424 ms

499 ms

2410 ms

Sample time

4.17 ms

5 ms

25 ms

A.2.3.2

Sample time for the built-in analog ports of the CPU

Table A- 19

Sample time for built-in analog inputs of the CPU

Rejection frequency(Integration time selection)

Sample time

60 Hz(16.6 ms)

4.17 ms

50 Hz (20 ms)

5 ms

10 Hz (100 ms)

25 ms

A.2.3.3

Measurement ranges of the analog inputs for voltage

Table A- 20

Analog input representation for voltage

System
Decimal

Voltage Measuring Range

Hexadecimal

±10 V

±5 V

±2.5 V

32767

7FFF

11.851 V

5.926 V

2.963 V

Overflow

11.851 V

Overflow

32512

7F00
11.759 V

5.879 V

2.940 V

Overshoot range

11.759 V

Overshoot
range

10 V

2.5 V

Rated range

10 V

Rated range

32511

7EFF

27649

6C01

27648

6C00

0 to 10 V

20736

5100

7.5 V

3.75 V

1.875 V

7.5 V

361.7 μV

180.8 μV

90.4 μV

361.7 μV

-1

FFFF

-20736

AF00

-7.5 V

-3.75 V

-1.875 V

-27648

9400

-10 V

-5 V

-2.5 V

Negative
values are not
supported

-27649

93FF

-32512

8100

-32513

80FF

-32768

8000

Undershoot range
-11.759 V

-5.879 V

-2.940 V

-11.851 V

-5.926 V

-2.963 V

Underflow

S7-1200 Programmable controller

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Technical specifications
A.2 CPU 1211C

A.2.4

Wiring diagrams
Table A- 21

CPU 1211C AC/DC/Relay (6ES7 211-1BD30-0XB0)

① 24 VDC Sensor Power

Out
For additional noise
immunity, connect "M"
to chassis ground even
if not using sensor
supply.

② For sinking inputs,
connect "-" to "M"
(shown).

For sourcing inputs,
connect "+" to "M".

Table A- 22

CPU 1211C DC/DC/Relay (6ES7 211-1HD30-0XB0)

① 24 VDC Sensor Power
Out

For additional noise
immunity, connect "M"
to chassis ground even
if not using sensor
supply.

② For sinking inputs,
connect "-" to "M"
(shown).

For sourcing inputs,
connect "+" to "M".

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Technical specifications
A.3 CPU 1212C
Table A- 23

CPU 1211C DC/DC/DC (6ES7 211-1AD30-0XB0)

① 24 VDC Sensor Power

Out

For additional noise
immunity, connect "M"
to chassis ground even
if not using sensor
supply.

② For sinking inputs,
connect "-" to "M"
(shown).

For sourcing inputs,
connect "+" to "M".

Note
Unused analog inputs should be shorted.

A.3

CPU 1212C

A.3.1

General specifications and features

Table A- 24

General

Technical data

CPU 1212C
AC/DC/Relay

CPU 1212C
DC/DC/Relay

CPU 1212C
DC/DC/DC

Order number

6ES7 212-1BD30-0XB0

6ES7 212-1HD30-0XB0

6ES7 212-1AD30-0XB0

Dimensions W x H x D (mm)

90 x 100 x 75

Weight

425 grams

385 grams

370 grams

Power dissipation

11 W

Current available
(SM and CM bus)

1000 mA max.
(5 VDC)

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Technical specifications
A.3 CPU 1212C

Technical data

CPU 1212C
AC/DC/Relay

CPU 1212C
DC/DC/Relay

CPU 1212C
DC/DC/DC

Current available (24 VDC)

300 mA max.
(sensor power)

Digital input current consumption (24
VDC)

4 mA/input used

Table A- 25

CPU features

Technical data
User

memory1

Description
Work

25 Kbytes

Load

1 Mbytes

Retentive

2 Kbytes

On-board digital I/O

8 inputs/6 outputs

On-board analog I/O

2 inputs

Process image size

1024 bytes of inputs (I)/1024 bytes of outputs (Q)

Bit memory (M)

4096 bytes

Signal modules expansion

2 SMs max.

Signal board expansion

1 SB max.

Communication module expansion

3 CMs max.

High-speed counters

4 total


Single phase: 3 at 100 kHz and 1 at 30 kHz clock rate



Quadrature phase: 3 at 80 kHz and 1 at 20 kHz clock rate

Pulse outputs 2

Pulse catch inputs

Time delay / cyclic interrupts

4 total with 1 ms resolution

Edge interrupts

8 rising and 8 falling (12 and 12 with optional signal board)

Memory card

SIMATIC Memory Card (optional)

Real time clock accuracy

+/- 60 seconds/month

Real time clock retention time

10 days typ./6 days min. at 40°C (maintenance-free Super Capacitor)

For CPU models with relay outputs, you must install a digital signal board (SB) to use the pulse outputs.

Table A- 26

Performance

Type of instruction

Execution speed

Boolean

0.1 μs/instruction

Move Word

12 μs/instruction

Real math

18 μs/instruction

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Technical specifications
A.3 CPU 1212C
Table A- 27

Blocks, timers and counters supported by S7-1200

Element

Description

Blocks

Type

OB, FB, FC, DB

Size

25 Kbytes (CPU 1211C and CPU 1212C)
50 Kbytes (CPU 1214C)

OBs

Timers

Counters

Quantity

Up to 1024 blocks total (OBs + FBs + FCs + DBs)

Address range for FBs, FCs,
and DBs

1 to 65535 (such as FB 1 to FB 65535)

Nesting depth

16 from the program cycle or start up OB; 4 from the time delay
interrupt, time-of-day interrupt, cyclic interrupt, hardware interrupt,
time error interrupt, or diagnostic error interrupt OB

Monitoring

Status of 2 code blocks can be monitored simultaneously

Program cycle

Multiple: OB 1, OB 200 to OB 65535

Startup

Multiple: OB 100, OB 200 to OB 65535

Time-delay interrupts and
cyclic interrupts

41 (1 per event): OB 200 to OB 65535

Hardware interrupts (edges
and HSC)

50 (1 per event): OB 200 to OB 65535

Time error interrupts

1: OB 80

Diagnostic error interrupts

1: OB 82

Type

IEC

Quantity

Limited only by memory size

Storage

Structure in DB, 16 bytes per timer

Type

IEC

Quantity

Limited only by memory size

Storage

Structure in DB, size dependent upon count type


SInt, USInt: 3 bytes



Int, UInt: 6 bytes



DInt, UDInt: 12 bytes

Table A- 28

Communication

Technical data

Description

Number of ports

Type

Ethernet

Connections



4 for HMI



3 for programming device



8 for Ethernet instructions in the user program



8 for CPU-to-CPU

Data rates

10/100 Mb/s

S7-1200 Programmable controller

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Technical specifications
A.3 CPU 1212C

Technical data

Description

Isolation (external signal to PLC logic)

Transformer isolated, 1500 VDC

Cable type

CAT5e shielded

Table A- 29

Power supply

Technical data

CPU 1212C
AC/DC/Relay

CPU 1212C
DC/DC/Relay

CPU 1212C
DC/DC/DC

Voltage range

85 to 264 VAC

20.4 to 28.8 VDC

Line frequency

47 to 63 Hz

CPU only

80 mA at 120 VAC
40 mA at 240 VAC

400 mA at 24 VDC

CPU with all expansion
accessories

240 mA at 120 VAC
120 mA at 240 VAC

1200 mA at 24 VDC

Inrush current (max.)

20 A at 264 VAC

12 A at 28.8 VDC

Isolation (input power to logic)

1500 VAC

Not isolated

Ground leakage, AC line to functional earth

0.5 mA max.

Hold up time (loss of power)

20 ms at 120 VAC
80 ms at 240 VAC

10 ms at 24 VDC

Internal fuse, not user replaceable

3 A, 250 V, slow blow

CPU 1212C
AC/DC/Relay

CPU 1212C
DC/DC/Relay

CPU 1212C
DC/DC/DC

Input current
(max. load)

Table A- 30

Sensor power

Technical data
Voltage range

20.4 to 28.8 VDC

L+ minus 4 VDC min.

Output current rating (max.)

300 mA (short circuit
protected)

Maximum ripple noise (<10 MHz)

< 1 V peak to peak

Same as input line

Isolation (CPU logic to sensor power)

Not isolated

A.3.2
Table A- 31

Digital inputs and outputs
Digital inputs

Technical data

CPU 1212C AC/DC/Relay, DC/DC/Relay, and DC/DC/DC

Number of inputs

Type

Sink/Source (IEC Type 1 sink)

Rated voltage

24 VDC at 4 mA, nominal

Continuous permissible voltage

30 VDC, max.

Surge voltage

35 VDC for 0.5 sec.

Logic 1 signal (min.)

15 VDC at 2.5 mA

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Technical specifications
A.3 CPU 1212C

Technical data

CPU 1212C AC/DC/Relay, DC/DC/Relay, and DC/DC/DC

Logic 0 signal (max.)

5 VDC at 1 mA

Isolation (field side to logic)

500 VAC for 1 minute

Isolation groups

Filter times

0.2, 0.4, 0.8, 1.6, 3.2, 6.4, and 12.8 ms (selectable in groups of 4)

HSC clock input rates (max.)
(Logic 1 Level = 15 to 26 VDC)

Single phase: 100 KHz (Ia.0 to Ia.5) and 30 KHz (Ia.6 to Ia.7)
Quadrature phase: 80 KHz (Ia.0 to Ia.5) and 20 KHz (Ia.6 to Ia.7)

Number of inputs on simultaneously

Cable length (meters)

500 m shielded, 300 m unshielded, 50 m shielded for HSC inputs

Table A- 32

Digital outputs

Technical data

CPU 1212C AC/DC/Relay
and DC/DC/Relay

CPU 1212C
DC/DC/DC

Number of outputs

Type

Relay, dry contact

Solid state - MOSFET (sourcing)

Voltage range

5 to 30 VDC or 5 to 250 VAC

20.4 to 28.8 VDC

Logic 1 signal at max. current

20 VDC min.

Logic 0 signal with 10 KΩ load

0.1 VDC max.

Current (max.)

2.0 A

0.5 A

Lamp load

30 W DC / 200 W AC

ON state resistance

0.2 Ω max. when new

0.6 Ω max.

Leakage current per point

10 μA max.

Surge current

7 A with contacts closed

8 A for 100 ms max.

Overload protection

Isolation (field side to logic)

1500 VAC for 1 minute (coil to contact)

500 VAC for 1 minute

None (coil to logic)
Isolation resistance

100 MΩ min. when new

Isolation between open contacts

750 VAC for 1 minute

Isolation groups

Inductive clamp voltage

L+ minus 48 VDC, 1 W dissipation

Switching delay (Qa.0 to Qa.3)

10 ms max.

1.0 μs max., off to on
3.0 μs max., on to off

Switching delay (Qa.4 to Qa.5)

10 ms max.

50 μs max., off to on
200 μs max., on to off

Maximum relay switching frequency

1 Hz

Pulse Train Output rate
(Qa.0 and Qa.2)

Not recommended

Lifetime mechanical (no load)

10,000,000 open/close cycles

Lifetime contacts at rated load

100,000 open/close cycles

Behavior on RUN to STOP

Last value or substitute value
(default value 0)

Last value or substitute value (default
value 0)

-1

100 KHz max.,
2 Hz min.2

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Technical specifications
A.3 CPU 1212C

Technical data

CPU 1212C AC/DC/Relay
and DC/DC/Relay

CPU 1212C
DC/DC/DC

Number of Outputs On
simultaneously

Cable length (meters)

500 m shielded,
150 m unshielded

For CPU models with relay outputs, you must install a digital signal board (SB) to use the pulse outputs.

Depending on your pulse receiver and cable, an additional load resistor (at least 10% of rated current) may improve
pulse signal quality and noise immunity.

A.3.3
Table A- 33

Analog inputs
Analog inputs

Technical data

Description

Number of inputs

Type

Voltage (single-ended)

Range

0 to 10 V

Full-scale range (data word)

0 to 27648

Overshoot range (data word)

27,649 to 32,511
See the table for measurement ranges of the analog inputs for voltage
(Page 580).

Overflow (data word)

32,512 to 32,767

Resolution

10 bits

Maximum withstand voltage

35 VDC

Smoothing

None, Weak, Medium, or Strong
See the table for step response (ms) for the analog inputs of the CPU
(Page 580).

Noise rejection

10, 50, or 60 Hz

Impedance

≥100 KΩ

Isolation (field side to logic)

None

Accuracy (25°C / 0 to 55°C)

3.0% / 3.5% of full-scale

Common mode rejection

40 dB, DC to 60 Hz

Operational signal range

Signal plus common mode voltage must be less than +12 V and greater
than -12 V

Cable length (meters)

100 m, shielded twisted pair

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Technical specifications
A.3 CPU 1212C

A.3.3.1

Step response of the built-in analog inputs of the CPU

Table A- 34

Step Response (ms), 0V to 10V measured at 95%

Smoothing selection (sample averaging)

Rejection frequency (Integration time)
60 Hz

50 Hz

10 Hz

None (1 cycle): No averaging

63 ms

65 ms

130 ms

Weak (4 cycles): 4 samples

84 ms

93 ms

340 ms

Medium (16 cycles): 16 samples

221 ms

258 ms

1210 ms

Strong (32 cycles): 32 samples

424 ms

499 ms

2410 ms

Sample time

4.17 ms

5 ms

25 ms

A.3.3.2

Sample time for the built-in analog ports of the CPU

Table A- 35

Sample time for built-in analog inputs of the CPU

Rejection frequency(Integration time selection)

Sample time

60 Hz(16.6 ms)

4.17 ms

50 Hz (20 ms)

5 ms

10 Hz (100 ms)

25 ms

A.3.3.3

Measurement ranges of the analog inputs for voltage

Table A- 36

Analog input representation for voltage

System
Decimal

Voltage Measuring Range

Hexadecimal

±10 V

±5 V

±2.5 V

32767

7FFF

11.851 V

5.926 V

2.963 V

Overflow

11.851 V

Overflow

32512

7F00
11.759 V

5.879 V

2.940 V

Overshoot range

11.759 V

Overshoot
range

10 V

2.5 V

Rated range

10 V

Rated range

32511

7EFF

27649

6C01

27648

6C00

0 to 10 V

20736

5100

7.5 V

3.75 V

1.875 V

7.5 V

361.7 μV

180.8 μV

90.4 μV

361.7 μV

-1

FFFF

-20736

AF00

-7.5 V

-3.75 V

-1.875 V

-27648

9400

-10 V

-5 V

-2.5 V

Negative
values are not
supported

-27649

93FF

-32512

8100

-32513

80FF

-32768

8000

Undershoot range
-11.759 V

-5.879 V

-2.940 V

-11.851 V

-5.926 V

-2.963 V

Underflow

S7-1200 Programmable controller

580

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Technical specifications
A.3 CPU 1212C

A.3.4

Wiring diagrams
Table A- 37

CPU 1212C AC/DC/Relay (6ES7 212-1BD30-0XB0)

① 24 VDC Sensor Power
Out

For additional noise
immunity, connect "M"
to chassis ground even
if not using sensor
supply.

② For sinking inputs,
connect "-" to "M"
(shown).

For sourcing inputs,
connect "+" to "M".

Table A- 38

CPU 1212C DC/DC/Relay (6ES7 212-1HD30-0XB0)

① 24 VDC Sensor Power
Out

For additional noise
immunity, connect "M"
to chassis ground even
if not using sensor
supply.

② For sinking inputs,
connect "-" to "M"
(shown).

For sourcing inputs,
connect "+" to "M".

S7-1200 Programmable controller
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Technical specifications
A.4 CPU 1214C
Table A- 39

CPU 1212C DC/DC/DC (6ES7-212-1AD30-0XB0)

① 24 VDC Sensor Power

Out

For additional noise
immunity, connect "M"
to chassis ground even
if not using sensor
supply.

② For sinking inputs,
connect "-" to "M"
(shown).

For sourcing inputs,
connect "+" to "M".

Note
Unused analog inputs should be shorted.

A.4

CPU 1214C

A.4.1

General specifications and features

Table A- 40

General

Technical data

CPU 1214C
AC/DC/Relay

CPU 1214C
DC/DC/Relay

CPU 1214C
DC/DC/DC

Order number

6ES7 214-1BE30-0XB0

6ES7 214-1HE30-0XB0

6ES7 214-1AE30-0XB0

Dimensions W x H x D (mm)

110 x 100 x 75

Weight

475 grams

435 grams

415 grams

Power dissipation

14 W

12 W

Current available (SM and CM bus)

1600 mA max.
(5 VDC)

S7-1200 Programmable controller

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Technical specifications
A.4 CPU 1214C

Technical data

CPU 1214C
AC/DC/Relay

CPU 1214C
DC/DC/Relay

CPU 1214C
DC/DC/DC

Current available (24 VDC)

400 mA max.
(sensor power)

Digital input current consumption
(24VDC)

4 mA/input used

Table A- 41

CPU features

Technical data
User

memory1

Description
Work

50 Kbytes

Load

2 Mbytes

Retentive

2 Kbytes

On-board digital I/O

14 inputs/10 outputs

On-board analog I/O

2 inputs

Process image size

1024 bytes of inputs (I)/1024 bytes of outputs (Q)

Bit memory (M)

8192 bytes

Signal modules expansion

8 SMs max.

Signal board expansion

1 SB max.

Communication module expansion

3 CMs max.

High-speed counters

6 total


Single phase: 3 at 100 kHz and 3 at 30 kHz clock rate



Quadrature phase: 3 at 80 kHz and 3 at 20 kHz clock rate

Pulse outputs 2

Pulse catch inputs

Time delay / cyclic interrupts

4 total with 1 ms resolution

Edge interrupts

12 rising and 12 falling (14 and 14 with optional signal board)

Memory card

SIMATIC Memory Card (optional)

Real time clock accuracy

+/- 60 seconds/month

Real time clock retention time

10 days typ./6 days min. at 40°C (maintenance-free Super Capacitor)

For CPU models with relay outputs, you must install a digital signal board (SB) to use the pulse outputs.

Table A- 42

Performance

Type of instruction

Execution speed

Boolean

0.1 μs/instruction

Move Word

12 μs/instruction

Real math

18 μs/instruction

S7-1200 Programmable controller
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Technical specifications
A.4 CPU 1214C
Table A- 43

Blocks, timers and counters supported by S7-1200

Element

Description

Blocks

Type

OB, FB, FC, DB

Size

25 Kbytes (CPU 1211C and CPU 1212C)
50 Kbytes (CPU 1214C)

OBs

Timers

Counters

Quantity

Up to 1024 blocks total (OBs + FBs + FCs + DBs)

Address range for FBs, FCs,
and DBs

1 to 65535 (such as FB 1 to FB 65535)

Nesting depth

16 from the program cycle or start up OB; 4 from the time delay
interrupt, time-of-day interrupt, cyclic interrupt, hardware interrupt,
time error interrupt, or diagnostic error interrupt OB

Monitoring

Status of 2 code blocks can be monitored simultaneously

Program cycle

Multiple: OB 1, OB 200 to OB 65535

Startup

Multiple: OB 100, OB 200 to OB 65535

Time-delay interrupts and
cyclic interrupts

41 (1 per event): OB 200 to OB 65535

Hardware interrupts (edges
and HSC)

50 (1 per event): OB 200 to OB 65535

Time error interrupts

1: OB 80

Diagnostic error interrupts

1: OB 82

Type

IEC

Quantity

Limited only by memory size

Storage

Structure in DB, 16 bytes per timer

Type

IEC

Quantity

Limited only by memory size

Storage

Structure in DB, size dependent upon count type


SInt, USInt: 3 bytes



Int, UInt: 6 bytes



DInt, UDInt: 12 bytes

Table A- 44

Communication

Technical data

Description

Number of ports

Type

Ethernet

Connections



4 for HMI



3 for programming device



8 for Ethernet instructions in the user program



8 for CPU-to-CPU

Data rates

10/100 Mb/s

S7-1200 Programmable controller

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Technical specifications
A.4 CPU 1214C

Technical data

Description

Isolation (external signal to PLC logic)

Transformer isolated, 1500 VDC

Cable type

CAT5e shielded

Table A- 45

Power supply

Technical data

CPU 1214C
AC/DC/Relay

CPU 1214C
DC/DC/Relay

Voltage range

85 to 264 VAC

20.4 to 28.8 VDC

Line frequency

47 to 63 Hz

CPU only

100 mA at 120 VAC
50 mA at 240 VAC

500 mA at 24 VDC

CPU with all expansion
accessories

300 mA at 120 VAC
150 mA at 240 VAC

1500 mA at 24 VDC

Inrush current (max.)

20 A at 264 VAC

12 A at 28.8 VDC

Isolation (input power to logic)

1500 VAC

Not isolated

Ground leakage, AC line to functional
earth

0.5 mA max.

Hold up time (loss of power)

20 ms at 120 VAC
80 ms at 240 VAC

10 ms at 24 VDC

Internal fuse, not user replaceable

3 A, 250 V, slow blow

Input current
(max. load)

Table A- 46

CPU 1214C
DC/DC/DC

Sensor power

Technical data

CPU 1214C
AC/DC/Relay

CPU 1214C
DC/DC/Relay

Voltage range

20.4 to 28.8 VDC

L+ minus 4 VDC min.

Output current rating (max.)

400 mA (short circuit protected)

Maximum ripple noise (<10 MHz)

< 1 V peak to peak

Isolation (CPU logic to sensor power)

Not isolated

A.4.2
Table A- 47

CPU 1214C
DC/DC/DC

Same as input line

Digital inputs and outputs
Digital inputs

Technical data

CPU 1214C
AC/DC/Relay

CPU 1214C
DC/DC/Relay

Number of inputs

Type

Sink/Source (IEC Type 1 sink)

Rated voltage

24 VDC at 4 mA, nominal

Continuous permissible voltage

30 VDC, max.

Surge voltage

35 VDC for 0.5 sec.

CPU 1214C
DC/DC/DC

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Technical specifications
A.4 CPU 1214C

Technical data

CPU 1214C
AC/DC/Relay

Logic 1 signal (min.)

15 VDC at 2.5 mA

Logic 0 signal (max.)

5 VDC at 1 mA

Isolation (field side to logic)

500 VAC for 1 minute

Isolation groups

Filter times

0.2, 0.4, 0.8, 1.6, 3.2, 6.4, and 12.8 ms (selectable in groups of 4)

HSC clock input rates (max.)
(Logic 1 Level = 15 to 26 VDC)

Single phase: 100 KHz (Ia.0 to Ia.5) and 30 KHz (Ia.6 to Ib.5)
Quadrature phase: 80 KHz (Ia.0 to Ia.5) and 20 KHz (Ia.6 to Ib.5)

Number of inputs on simultaneously

Cable length (meters)

500 m shielded, 300 m unshielded, 50 m shielded for HSC inputs

Table A- 48

CPU 1214C
DC/DC/Relay

CPU 1214C
DC/DC/DC

Digital outputs

Technical data

CPU 1214C AC/DC/Relay
and DC/DC/Relay

CPU 1214C
DC/DC/DC

Number of outputs

Type

Relay, dry contact

Solid state - MOSFET (sourcing)

Voltage range

5 to 30 VDC or 5 to 250 VAC

20.4 to 28.8 VDC

Logic 1 signal at max. current

20 VDC min.

Logic 0 signal with 10 KΩ load

0.1 VDC max.

Current (max.)

2.0 A

0.5 A

Lamp load

30 W DC / 200 W AC

ON state resistance

0.2 Ω max. when new

0.6 Ω max.

Leakage current per point

10 μA max.

Surge current

7 A with contacts closed

8 A for 100 ms max.

Overload protection

Isolation (field side to logic)

1500 VAC for 1 minute (coil to contact)

500 VAC for 1 minute

None (coil to logic)
Isolation resistance

100 MΩ min. when new

Isolation between open contacts

750 VAC for 1 minute

Isolation groups

Inductive clamp voltage

L+ minus 48 VDC,
1 W dissipation

Switching delay (Qa.0 to Qa.3)

10 ms max.

1.0 μs max., off to on
3.0 μs max., on to off

Switching delay (Qa.4 to Qb.1)

10 ms max.

50 μs max., off to on
200 μs max., on to off

Maximum relay switching frequency

1 Hz

Pulse Train Output rate
(Qa.0 and Qa.2)

Not recommended 1

100 KHz max.,
2 Hz min. 2

Lifetime mechanical (no load)

10,000,000 open/close cycles

Lifetime contacts at rated load

100,000 open/close cycles

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Technical specifications
A.4 CPU 1214C

Technical data

CPU 1214C AC/DC/Relay
and DC/DC/Relay

Behavior on RUN to STOP

Last value or substitute value (default value 0)

Number of Outputs On
simultaneously

Cable length (meters)

500 m shielded, 150 m unshielded

CPU 1214C
DC/DC/DC

For CPU models with relay outputs, you must install a digital signal board (SB) to use the pulse outputs.

Depending on your pulse receiver and cable, an additional load resistor (at least 10% of rated current) may improve
pulse signal quality and noise immunity.

A.4.3
Table A- 49

Analog inputs
Analog inputs

Technical data

Description

Number of inputs

Type

Voltage (single-ended)

Range

0 to 10 V

Full-scale range (data word)

0 to 27648

Overshoot range (data word)

27,649 to 32,511
See the table for measurement ranges of the analog inputs for voltage
(Page 588).

Overflow (data word)

32,512 to 32,767

Resolution

10 bits

Maximum withstand voltage

35 VDC

Smoothing

None, Weak, Medium, or Strong
See the table for step response (ms) for the analog inputs of the CPU
(Page 588).

Noise rejection

10, 50, or 60 Hz

Impedance

≥100 KΩ

Isolation (field side to logic)

None

Accuracy (25°C / 0 to 55°C)

3.0% / 3.5% of full-scale

Common mode rejection

40 dB, DC to 60 Hz

Operational signal range

Signal plus common mode voltage must be less than +12 V and greater
than -12 V

Cable length (meters)

100 m, shielded twisted pair

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Technical specifications
A.4 CPU 1214C

A.4.3.1

Step response of the built-in analog inputs of the CPU

Table A- 50

Step Response (ms), 0V to 10V measured at 95%

Smoothing selection (sample averaging)

Rejection frequency (Integration time)
60 Hz

50 Hz

10 Hz

None (1 cycle): No averaging

63 ms

65 ms

130 ms

Weak (4 cycles): 4 samples

84 ms

93 ms

340 ms

Medium (16 cycles): 16 samples

221 ms

258 ms

1210 ms

Strong (32 cycles): 32 samples

424 ms

499 ms

2410 ms

Sample time

4.17 ms

5 ms

25 ms

A.4.3.2

Sample time for the built-in analog ports of the CPU

Table A- 51

Sample time for built-in analog inputs of the CPU

Rejection frequency(Integration time selection)

Sample time

60 Hz(16.6 ms)

4.17 ms

50 Hz (20 ms)

5 ms

10 Hz (100 ms)

25 ms

A.4.3.3

Measurement ranges of the analog inputs for voltage

Table A- 52

Analog input representation for voltage

System
Decimal

Voltage Measuring Range

Hexadecimal

±10 V

±5 V

±2.5 V

32767

7FFF

11.851 V

5.926 V

2.963 V

Overflow

11.851 V

Overflow

32512

7F00
11.759 V

5.879 V

2.940 V

Overshoot range

11.759 V

Overshoot
range

10 V

2.5 V

Rated range

10 V

Rated range

32511

7EFF

27649

6C01

27648

6C00

0 to 10 V

20736

5100

7.5 V

3.75 V

1.875 V

7.5 V

361.7 μV

180.8 μV

90.4 μV

361.7 μV

-1

FFFF

-20736

AF00

-7.5 V

-3.75 V

-1.875 V

-27648

9400

-10 V

-5 V

-2.5 V

Negative
values are not
supported

-27649

93FF

-32512

8100

-32513

80FF

-32768

8000

Undershoot range
-11.759 V

-5.879 V

-2.940 V

-11.851 V

-5.926 V

-2.963 V

Underflow

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Technical specifications
A.4 CPU 1214C

A.4.4

CPU 1214C Wiring Diagrams
Table A- 53

CPU 1214C AC/DC/Relay (6ES7 214-1BE30-0XB0)

① 24 VDC Sensor Power
Out

For additional noise
immunity, connect "M"
to chassis ground even
if not using sensor
supply.

② For sinking inputs,
connect "-" to "M"
(shown).

For sourcing inputs,
connect "+" to "M".

Table A- 54

CPU 1214C DC/DC/Relay (6ES7 214-1HE30-0XB0)

① 24 VDC Sensor Power
Out

For additional noise
immunity, connect "M"
to chassis ground even
if not using sensor
supply.

② For sinking inputs,
connect "-" to "M"
(shown).

For sourcing inputs,
connect "+" to "M".

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Technical specifications
A.5 Digital signal modules (SMs)
Table A- 55

CPU 1214C DC/DC/DC (6ES7 214-1AE30-0XB0)

① 24 VDC Sensor Power

Out

For additional noise
immunity, connect "M"
to chassis ground even
if not using sensor
supply.

② For sinking inputs,
connect "-" to "M"
(shown).

For sourcing inputs,
connect "+" to "M".

Note
Unused analog inputs should be shorted.

A.5

Digital signal modules (SMs)

A.5.1

SM 1221 Digital Input Specifications

Table A- 56

General specifications

Model

SM 1221 DI 8 x 24 VDC

SM 1221 DI 16 x 24 VDC

Order number

6ES7 221-1BF30-0XB0

6ES7 221-1BH30-0XB0

Dimensions W x H x D (mm)

45 x 100 x 75

Weight

170 grams

210 grams

Power dissipation

1.5 W

2.5 W

Current consumption (SM Bus)

105 mA

130 mA

Current consumption (24 VDC)

4 mA / input used

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Technical specifications
A.5 Digital signal modules (SMs)
Table A- 57

Digital inputs

Model

SM 1221 DI 8 x 24 VDC

SM 1221 DI 16 x 24 VDC

Number of inputs

Type

Sink/Source (IEC Type 1 sink)

Rated voltage

24 VDC at 4 mA, nominal

Continuous permissible voltage

30 VDC, max.

Surge voltage

35 VDC for 0.5 sec.

Logic 1 signal (min.)

15 VDC at 2.5 mA

Logic 0 signal (max.)

5 VDC at 1 mA

Isolation (field side to logic)

500 VAC for 1 minute

Isolation groups

Filter times

0.2, 0.4, 0.8, 1.6, 3.2, 6.4, and 12.8 ms
(selectable in groups of 4)

Number of inputs on simultaneously

Cable length (meters)

500 m shielded, 300 unshielded

Table A- 58

Wiring diagrams for the digital input SMs

SM 1221 DI 8 x 24 VDC (6ES7 221-1BF30-0XB0)

SM 1221 DI 16 x 24 VDC (6ES7 221-1BH30-0XB0)

① For sinking inputs, connect "-" to "M" (shown). For sourcing inputs, connect "+" to "M".

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Technical specifications
A.5 Digital signal modules (SMs)

A.5.2
Table A- 59

SM 1222 Digital Output Specifications
General specifications

Model

SM 1222
DQ 8 x Relay

SM1222
DQ 16 x Relay

Order number

6ES7 222-1HF300XB0

6ES7 222-1HH30- 6ES7 222-1BF300XB0
0XB0

6ES7 222-1BH300XB0

Dimensions W x H x D (mm)

45 x 100 x 75

Weight

190 grams

260 grams

180 grams

220 grams

Power dissipation

4.5 W

8.5 W

1.5 W

2.5 W

Current consumption (SM Bus)

120 mA

135 mA

120 mA

140 mA

Current consumption (24 VDC)

11 mA / Relay coil used

Model

SM 1222
DQ 8 x Relay

SM1222
DQ 16 x Relay

SM1222
DQ 8 x 24 VDC

SM1222
DQ 16 x 24 VDC

Number of outputs

Type

Relay, dry contact

Solid state - MOSFET (sourcing)

Voltage range

5 to 30 VDC or 5 to 250 VAC

20.4 to 28.8 VDC

Logic 1 signal at max. current

20 VDC min.

Logic 0 signal with 10K Ω load

0.1 VDC max.

Current (max.)

2.0 A

0.5 A

Lamp load

30 W DC/200 W AC

ON state contact resistance

0.2 Ω max. when new

0.6 Ω max.

Leakage current per point

10 μA max.

Surge current

7 A with contacts closed

8 A for 100 ms max.

Overload protection

Isolation (field side to logic)

1500 VAC for 1 minute (coil to contact)
None (coil to logic)

500 VAC for 1 minute

Isolation resistance

100 MΩ min. when new

Isolation between open contacts

750 VAC for 1 minute

Isolation groups

Current per common (max.)

10 A

Inductive clamp voltage

L+ minus 48 V, 1 W dissipation

Switching delay

10 ms max.

50 μs max. off to on

Table A- 60

SM1222
DQ 8 x 24 VDC

SM1222
DQ 16 x 24 VDC

Digital outputs

200 μs max. on to off
Maximum relay switching frequency

1 Hz

Lifetime mechanical (no load)

10,000,000 open/close cycles

Lifetime contacts at rated load

100,000 open/close cycles

Behavior on RUN to STOP

Last value or substitute value (default value 0)

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Technical specifications
A.5 Digital signal modules (SMs)

Model

SM 1222
DQ 8 x Relay

SM1222
DQ 16 x Relay

SM1222
DQ 8 x 24 VDC

SM1222
DQ 16 x 24 VDC

Number of outputs on simultaneously

Cable length (meters)

500 m shielded, 150 m unshielded

Table A- 61

Wiring diagrams for the 8-point digital output SMs

SM 1222 DQ 8 x Relay (6ES7 222-1HF30-0XB0)

SM 1222 DQ 8 x 24 VDC (6ES7 222-1BF30-0XB0

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Technical specifications
A.5 Digital signal modules (SMs)
Table A- 62

Wiring diagrams for the 16-point digital output SMs

SM 1222 DQ 16 x Relay (6ES7 222-1HH30-0XB0)

A.5.3
Table A- 63

SM 1222 DQ 16 x 24 VDC (6ES7 222-1BH30-0XB0)

SM 1223 Digital Input/Output VDC Specifications
General specifications

Model

SM 1223
SM 1223
DI 8 x 24 VDC, DQ DI 16 x 24 VDC,
DQ 16 x Relay
8 x Relay

SM 1223
SM 1223
DI 8 x 24 VDC, DQ DI 16 x 24 VDC,
DQ 16 x 24 VDC
8 x 24 VDC

Order number

6ES7 223-1PH300XB0

6ES7 223-1PL300XB0

6ES7 223-1BH300XB0

6ES7 223-1BL300XB0

Dimensions W x H x D (mm)

45 x 100 x 75

70 x 100 x 75

45 x 100 x 75

70 x 100 x 75

Weight

230 grams

350 grams

210 grams

310 grams

Power dissipation

5.5 W

10 W

2.5 W

4.5 W

Current consumption (SM Bus)

145 mA

180 mA

145 mA

185 mA

Current consumption (24 VDC)

4 mA / Input used
11 mA / Relay coil used

4 mA / Input used

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Technical specifications
A.5 Digital signal modules (SMs)
Table A- 64

Digital inputs

Model

SM 1223
SM 1223
DI 8 x 24 VDC, DQ DI 16 x 24 VDC,
DQ 16 x Relay
8 x Relay

SM 1223
SM 1223
DI 8 x 24 VDC, DQ DI 16 x 24 VDC,
DQ 16 x 24 VDC
8 x 24 VDC

Number of inputs

Type

Sink/Source (IEC Type 1 sink)

Rated voltage

24 VDC at 4 mA, nominal

Continuous permissible voltage

30 VDC max.

Surge voltage

35 VDC for 0.5 sec.

Logic 1 signal (min.)

15 VDC at 2.5 mA

Logic 0 signal (max.)

5 VDC at 1 mA

Isolation (field side to logic)

500 VAC for 1 minute

Isolation groups

Filter times

0.2, 0.4, 0.8, 1.6, 3.2, 6.4, and 12.8 ms, selectable in groups of 4

Number of inputs on simultaneously

Cable length (meters)

500 m shielded, 300 m unshielded

Table A- 65

Digital outputs

Model

SM 1223
SM 1223
DI 8 x 24 VDC, DQ DI 16 x 24 VDC,
DQ 16 x Relay
8 x Relay

SM 1223
SM 1223
DI 8 x 24 VDC, DQ DI 16 x 24 VDC, DQ
16 x 24 VDC
8 x 24 VDC

Number of outputs

Type

Relay, dry contact

Solid state - MOSFET (sourcing)

Voltage range

5 to 30 VDC or 5 to 250 VAC

20.4 to 28.8 VDC

Logic 1 signal at max. current

20 VDC, min.

Logic 0 signal with 10 KΩ load

0.1 VDC, max.

Current (max.)

2.0 A

0.5 A

Lamp load

30 W DC / 200 W AC

ON state contact resistance

0.2 Ω max. when new

0.6 Ω max.

Leakage current per point

10 μA max.

Surge current

7 A with contacts closed

8 A for 100 ms max.

Overload protection

Isolation (field side to logic)

1500 VAC for 1 minute (coil to contact)
None (coil to logic)

500 VAC for 1 minute

Isolation resistance

100 MΩ min. when new

Isolation between open contacts

750 VAC for 1 minute

Isolation groups

Current per common

10A

Inductive clamp voltage

L+ minus 48 V, 1 W dissipation

Switching delay

10 ms max.

50 μs max. off to on
200 μs max. on to off

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Technical specifications
A.5 Digital signal modules (SMs)

Model

SM 1223
SM 1223
DI 8 x 24 VDC, DQ DI 16 x 24 VDC,
DQ 16 x Relay
8 x Relay

SM 1223
SM 1223
DI 8 x 24 VDC, DQ DI 16 x 24 VDC, DQ
16 x 24 VDC
8 x 24 VDC

Maximum relay switching frequency

1 Hz

Lifetime mechanical (no load)

10,000,000 open/close cycles

Lifetime contacts at rated load

100,000 open/close cycles

Behavior on RUN to STOP

Last value or substitute value (default value 0)

Number of outputs on simultaneously 8
Cable length (meters)

Table A- 66

500 m shielded, 150 m unshielded

Wiring diagrams for the digital input VDC/output relay SMs

SM 1223 DI 8 x 24 VDC, DQ 8 x Relay
(6ES7 223-1PH30-0XB0)

SM 1223 DI 16 x 24 VDC, DQ 16 x Relay
(6ES7 223-1PL30-0XB0)

Notes

① For sinking

inputs, connect "-"
to "M" (shown).
For sourcing inputs,
connect "+" to "M".

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Technical specifications
A.5 Digital signal modules (SMs)
Table A- 67

Wiring diagrams for the digital input VDC/output SMs

SM 1223 DI 8 x 24 VDC, DQ 8 x 24 VDC
(6ES7 223-1BH30-0XB0)

SM 1223 DI 16 x 24 VDC, DQ 16 x 24 VDC
(6ES7 223-1BL30-0XB0)

Notes

① For sinking

inputs, connect "-"
to "M" (shown).
For sourcing inputs,
connect "+" to "M".

A.5.4

SM 1223 Digital Input/Output AC Specifications
Note
To use this SM, your CPU firmware must be V2.0 or higher.

Table A- 68

General specifications

Model

SM 1223 DI 8 x120/230 VAC / DQ 8 x Relay

Order number

6ES7 223-1QH30-0XB0

Dimensions W x H x D (mm)

45 x 100 x 75 mm

Weight

190 grams

Power dissipation

7.5 W

Current consumption (SM Bus)

120 mA

Current consumption (24 VDC)

11 mA per output when on

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Technical specifications
A.5 Digital signal modules (SMs)
Table A- 69
Model

SM 1223 DI 8 x 120/230 VAC / DQ 8 x Relay

Number of inputs

Type

IEC Type 1

Rated voltage

120 VAC at 6 mA, 230 VAC at 9 mA

Continuous permissible voltage

264 VAC

Surge voltage

Logic 1 signal (min.)

79 VAC at 2.5 mA

Logic 0 signal (max.)

20 VAC at 1 mA

Leakage current (max.)

1 mA

Isolation (field side to logic)

1500 VAC for 1 minute

Isolation

Digital inputs

groups1

Input delay times

Typical: 0.2 to 12.8 ms, user selectable
Maximum: -

Connection of 2 wire proximity sensor (Bero)
(max.)

1 mA

Cable length

Unshielded: 300 meters
Shielded: 500 meters

Number of inputs on simultaneously

Channels within a group must be of the same phase.

Table A- 70

Digital outputs

Model

SM 1223 DI 8 x 120/230 VAC / DQ 8 x Relay

Number of outputs

Type

Relay, dry contact

Voltage range

5 to 30 VDC or 5 to 250 VAC

Logic 1 signal at max. current

Logic 0 signal with 10K Ω load

Current (max.)

2.0 A

Lamp load

30 W DC / 200 W AC

ON state contact resistance

0.2 Ω max. when new

Leakage current per point

Surge current

7 A with contacts closed

Overload protection

Isolation (field side to logic)

1500 VAC for 1 minute (coil to contact)
None (coil to logic)

Isolation resistance

100 MΩ min. when new

Isolation between open contacts

750 VAC for 1 minute

Isolation groups

Current per common (max.)

10 A

Inductive clamp voltage

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Technical specifications
A.5 Digital signal modules (SMs)

Model

SM 1223 DI 8 x 120/230 VAC / DQ 8 x Relay

Switching delay (max.)

10 ms

Maximum relay switching frequency

1 Hz

Lifetime mechanical (no load)

10,000,000 open/close cycles

Lifetime contacts at rated load

1000,000 open/close cycles

Behavior on RUN to STOP

Last value or substitute value (default value 0)

Number of outputs on simultaneously

Cable length (meters)

500 m shielded, 150 m unshielded

Note
The SM 1223 DI 8 x 120/230 VAC, DQ 8 x Relay (6ES7 223-1QH30-0XB0) signal module is
approved for use in Class 1, Division 2, Gas Group A, B, C, D, Temperature
Class T4 Ta = 40° C.

Table A- 71

SM 1223 DI 8 x 120/230 VAC, DQ 8 x Relay (6ES7 223-1QH30-0XB0)

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Technical specifications
A.6 Analog signal modules (SMs)

A.6

Analog signal modules (SMs)

A.6.1

SM 1231 analog input module specifications

Table A- 72

General specifications

Model

SM 1231 AI 4 x 13 bit

SM 1231 AI 8 x 13 bit

Order number

6ES7 231-4HD30-0XB0

6ES7 231-4HF30-0XB0

Dimensions W x H x D (mm)

45 x 100 x 75

Weight

180 grams

Power dissipation

1.5 W

Current consumption (SM Bus)

80 mA

90 mA

Current consumption (24 VDC)

45 mA

Table A- 73

Analog inputs

Model

SM 1231 AI 4 x 13 bit

SM 1231 AI 8 x 13 bit

Number of inputs

Type

Voltage or current (differential): Selectable in groups of 2

Range

±10 V, ±5 V, ±2.5 V, or 0 to 20 mA

Full scale range (data word)

-27,648 to 27,648

Overshoot/undershoot range
(data word)

Voltage: 32,511 to 27,649 / -27,649 to -32,512
Current: 32,511 to 27,649 / 0 to -4864
Refer to the section on analog input ranges for voltage and current
(Page 607).

Overflow/underflow (data word)

Voltage: 32,767 to 32,512 / -32,513 to -32,768
Current: 32,767 to 32,512 / -4865 to -32,768
Refer to the section on input ranges for voltage and current (Page 607).

Resolution

12 bits + sign bit

Maximum withstand voltage/current

±35 V / ±40 mA

Smoothing

None, weak, medium, or strong
Refer to the section on step response times (Page 606).

Noise rejection

400, 60, 50, or 10 Hz
Refer to the section on sample rates (Page 606).

Impedance

≥ 9 MΩ (voltage) / 250 Ω (current)

Isolation (field side to logic)

None

Accuracy (25°C / 0 to 55°C)

±0.1% / ±0.2% of full scale

Measuring principle

Actual value conversion

Common mode rejection

40 dB, DC to 60 Hz

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Technical specifications
A.6 Analog signal modules (SMs)

Model

SM 1231 AI 4 x 13 bit

Operational signal range

Signal plus common mode voltage must be less than +12 V and greater
than -12 V

Cable length (meters)

100 m, twisted and shielded

Table A- 74

SM 1231 AI 8 x 13 bit

Diagnostics

Model

SM 1231 AI 4 x 13 bit

SM 1231 AI 8 x 13 bit

Overflow/underflow

Yes 1

Yes

24 VDC low voltage

Yes

For SM 1231 AI 4 x 13 bit: If a voltage greater than +30 VDC or less than -15 VDC is applied to the input, the resulting
value will be unknown and the corresponding overflow or underflow may not be active.

Table A- 75

Wiring diagrams for the analog input SMs

SM 1231 AI 4 x 13 bit (6ES7 231-4HD30-0XB0)

SM 1231 AI 8 x 13 bit (6ES7 231-4HF30-0XB0)

Note
Unused analog inputs should be shorted.

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Technical specifications
A.6 Analog signal modules (SMs)

A.6.2
Table A- 76

SM 1232 analog output module specifications
General specifications

Technical data

SM 1232 AQ 2 x 14 bit

SM 1232 AQ 4 x 14 bit

Order number

6ES7 232-4HB30-0XB0

6ES7 232-4HD30-0XB0

Dimensions W x H x D (mm)

45 x 100 x 75

Weight

180 grams

Power dissipation

1.5 W

Current consumption (SM Bus)

80 mA

Current consumption (24 VDC)

45 mA (no load)

Technical data

SM 1232 AQ 2 x 14 bit

SM 1232 AQ 4 x 14 bit

Number of outputs

Type

Voltage or current

Range

±10 V or 0 to 20 mA

Resolution

Voltage: 14 bits

Current: 13 bits

Full scale range (data word)

Voltage: -27,648 to 27,648 ; Current: 0 to 27,648

Table A- 77

Analog outputs

Refer to the output ranges for voltage and current (Page 607).
Accuracy (25°C / 0 to 55°C)

±0.3% / ±0.6% of full scale

Settling time (95% of new value)

Voltage: 300 μS (R), 750 μS (1 uF)

Load impedance

Voltage: ≥ 1000 Ω

Current: 600 μS (1 mH), 2 ms (10 mH)
Current: ≤ 600 Ω
Behavior on RUN to STOP

Last value or substitute value (default value 0)

Isolation (field side to logic)

none

Cable length (meters)

100 m twisted and shielded

Table A- 78

Diagnostics

Technical data

SM 1232 AQ 2 x 14 bit

SM 1232 AQ 4 x 14 bit

Overflow/underflow

Yes

Short to ground (voltage mode only)

Yes

Wire break (current mode only)

Yes

24 VDC low voltage

Yes

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Technical specifications
A.6 Analog signal modules (SMs)
Table A- 79

Wiring diagrams for the analog output SMs

SM 1232 AQ 2 x 14 bit (6ES7 232-4HB30-0XB0)

A.6.3
Table A- 80

SM 1232 AQ 4 x 14 bit (6ES7 232-4HD30-0XB0)

SM 1234 analog input/output module specifications
General specifications

Technical data

SM 1234 AI 4 x 13 bit / AQ 2 x 14 bit

Order number

6ES7 234-4HE30-0XB0

Dimensions W x H x D (mm)

45 x 100 x 75

Weight

220 grams

Power dissipation

2.0 W

Current consumption (SM Bus)

80 mA

Current consumption (24 VDC)

60 mA (no load)

Table A- 81

Analog inputs

Model

SM 1234 AI 4 x 13 bit / AQ 2 x 14 bit

Number of inputs

Type

Voltage or Current (differential): Selectable in groups of 2

Range

±10 V, ±5 V, ±2.5 V, or 0 to 20 mA

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Technical specifications
A.6 Analog signal modules (SMs)

Model

SM 1234 AI 4 x 13 bit / AQ 2 x 14 bit

Full scale range (data word)

-27,648 to 27,648

Overshoot/undershoot range
(data word)

Voltage: 32,511 to 27,649 / -27,649 to -32,512
Current: 32,511 to 27,649 / 0 to -4864
Refer to the section on input ranges for voltage and current (Page 607).

Overflow/underflow (data word)

Voltage: 32,767 to 32,512 / -32,513 to -32,768
Current: 32,767 to 32,512 / -4865 to -32,768
Refer to the section on input ranges for voltage and current (Page 607).

Resolution

12 bits + sign bit

Maximum withstand voltage/current

±35 V / ±40 mA

Smoothing

None, weak, medium, or strong
Refer to the section on step response times (Page 606).

Noise rejection

400, 60, 50, or 10 Hz
Refer to the section on sample rates (Page 606).

Impedance

≥ 9 MΩ (voltage) / 250 Ω (current)

Isolation (field side to logic)

None

Accuracy (25°C / 0 to 55°C)

±0.1% / ±0.2% of full scale

Analog to digital conversion time

625 μs (400 Hz rejection)

Common mode rejection

40 dB, DC to 60 Hz

Operational signal range

Signal plus common mode voltage must be less than +12 V and greater
than -12 V

Cable length (meters)

100 m, twisted and shielded

Table A- 82

Analog outputs

Technical data

SM 1234 AI 4 x 13 bit / AQ 2 x 14 bit

Number of outputs

Type

Voltage or current

Range

±10 V or 0 to 20 mA

Resolution

Voltage: 14 bits ; Current: 13 bits

Full scale range (data word)

Voltage: -27,648 to 27,648 ; Current: 0 to 27,648
Refer to to the section on output ranges for voltage and current
(Page 607).

Accuracy (25°C / 0 to 55°C)

±0.3% / ±0.6% of full scale

Settling time (95% of new value)

Voltage: 300 μS (R), 750 μS (1 uF)
Current: 600 μS (1 mH), 2 ms (10 mH)

Load impedance

Voltage: ≥ 1000 Ω

Behavior on RUN to STOP

Last value or substitute value (default value 0)

Isolation (field side to logic)

none

Cable length (meters)

100 m twisted and shielded

Current: ≤ 600 Ω

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A.6 Analog signal modules (SMs)
Table A- 83

Diagnostics

Model

SM 1234 AI 4 x 13 bit / AQ 2 x 14 bit

Overflow/underflow

Yes 1

Short to ground (voltage mode only)

Yes on outputs

Wire break (current mode only)

Yes on outputs

24 VDC low voltage

Yes

If a voltage greater than +30 VDC or less than -15 VDC is applied to the input, the resulting value will be unknown and
the corresponding overflow or underflow may not be active.
Table A- 84

Wiring diagrams for the analog input/output SM

SM 1234 AI 4 x 13 Bit / AQ 2 x 14 bit (6ES7 234-4HE30-0XB0)

Note
Unused analog inputs should be shorted.

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A.6 Analog signal modules (SMs)

A.6.4
Table A- 85

Step response of the analog inputs
Step response (ms), 0 to full-scale measured at 95%

Smoothing selection (sample averaging)

Noise reduction/rejection frequency (Integration time selection)

None (1 cycle): No averaging

400 Hz (2.5 ms)

60 Hz (16.6 ms)

50 Hz (20 ms)

10 Hz (100 ms)

4 ms

18 ms

22 ms

100 ms

Weak (4 cycles): 4 samples

9 ms

52 ms

63 ms

320 ms

Medium (16 cycles): 16 samples

32 ms

203 ms

241 ms

1200 ms

Strong (32 cycles): 32 samples

61 ms

400 ms

483 ms

2410 ms

Sample time


4 channels



0.625 ms



4.17 ms



5 ms



25 ms



8 channels



1.25 ms



4.17 ms



5 ms



25 ms

A.6.5
Table A- 86

Sample time and update times for the analog inputs
Sample time and update time

Rejection frequency
(Integration time)
400 Hz (2.5 ms)

Sample time


4-channel SM: 0.625 ms



8-channel SM: 1.250 ms

Update time for all channels
4-channel SM

8-channel SM

2.5 ms

10 ms

60 Hz (16.6 ms)

4.170 ms

4.17 ms

50 Hz (20 ms)

5.000 ms

5 ms

10 Hz (100 ms)

25.000 ms

25 ms

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A.6 Analog signal modules (SMs)

A.6.6

Measurement ranges of the analog inputs for voltage

Table A- 87

Analog input representation for voltage

System
Decimal

Voltage Measuring Range

Hexadecimal

±10 V

±5 V

±2.5 V

32767

7FFF

11.851 V

5.926 V

2.963 V

Overflow

11.851 V

Overflow

32512

7F00

32511

7EFF

11.759 V

5.879 V

2.940 V

Overshoot range

11.759 V

27649

6C01

Overshoot
range

27648

6C00

10 V

2.5 V

Rated range

10 V

Rated range

20736

5100

7.5 V

3.75 V

1.875 V

7.5 V

361.7 μV

180.8 μV

90.4 μV

361.7 μV

-1

FFFF

-20736

AF00

-7.5 V

-3.75 V

-1.875 V

-27648

9400

-10 V

-5 V

-2.5 V

Negative
values are not
supported

-27649

93FF

-32512

8100

-11.759 V

-5.879 V

-2.940 V

-32513

80FF

-32768

8000

-11.851 V

-5.926 V

-2.963 V

A.6.7
Table A- 88

Undershoot range
Underflow

Output (AQ) measurement ranges for voltage and current (SB and SM)
Analog output representation for current
System

0 to 10 V

Current Output Range

Decimal

Hexadecimal

0 mA to 20 mA

32767

7FFF

See note 1

32512

7F00

See note 1

32511

7EFF

23.52 mA

Overshoot range

27649

6C01

27648

6C00

20 mA

Rated range

20736

5100

15 mA

723.4 nA

0 mA

Overflow

In an overflow or underflow condition, analog outputs will behave according to the device configuration properties set for
the analog signal module. In the "Reaction to CPU STOP" parameter, select either: Use substitute value or Keep last
value.

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A.7 Thermocouple and RTD signal modules (SMs)
Table A- 89

Analog output representation for voltage
System

Voltage Output Range

Decimal

Hexadecimal

± 10 V

32767

7FFF

See note 1

32512

7F00

See note 1

32511

7EFF

11.76 V

Overshoot range

27649

6C01

27648

6C00

10 V

Rated range

20736

5100

7.5 V

361.7 μ V

-1

FFFF

-361.7 μ V

-20736

AF00

-7.5 V

-27648

9400

-10 V

-27649

93FF

-32512

8100

-11.76 V

-32513

80FF

See note 1

-32768

8000

See note 1

Overflow

Undershoot range
Underflow

A.7

Thermocouple and RTD signal modules (SMs)

A.7.1

SM 1231 Thermocouple

Table A- 90

General specifications

Model

SM 1231 AI 4 x 16 bit TC

SM 1231 AI 8 x 16 bit TC

Order number

6ES7 231-5QD30-0XB0

6ES7 231-5QF30-0XB0

Dimensions W x H x D (mm)

45 x 100 x 75

Weight

180 grams

190 grams

Power dissipation

1.5 W

Current consumption (SM Bus)

80 mA

Current consumption (24 VDC) 1

40 mA

20.4 to 28.8 VDC (Class 2, Limited Power, or sensor power from PLC)

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A.7 Thermocouple and RTD signal modules (SMs)
Table A- 91

Analog inputs

Model

SM 1231 AI 4 x 16 bit TC

SM 1231 AI 8 x 16 bit TC

Number of inputs

Range

See Thermocouple selection table
(Page 611).

0.1° C/0.1° F

Nominal range (data word)
Overrange/underrange (data word)
Overflow/underflow (data word)
Resolution

Temperature

15 bits plus sign

Maximum withstand voltage

Voltage

± 35 V

Noise rejection

85 dB for selected filter setting
(10 Hz, 50 Hz, 60 Hz or 400 Hz)

Common mode rejection

> 120 dB at 120 VAC

Impedance

≥ 10 MΩ

Field to logic

500 VAC

Field to 24 VDC

500 VAC

24 VDC to logic

Isolation

500 VAC

Channel to channel

120 VAC

Accuracy (25°C / 0 to 55°C)

See Thermocouple selection table
(Page 611).

Repeatability

±0.05% FS

Measuring principle

Integrating

Module update time

See Noise reduction selection table
(Page 611).

Cold junction error

±1.5°C

Cable length (meters)

100 meters to sensor max.

Wire resistance

100 Ω max.

SM 1231 AI 4 x 16 bit TC

SM 1231 AI 8 x 16 bit TC

Yes

Table A- 92

Diagnostics

Model
Overflow/underflow 1
Wire break (current mode only)
24 VDC low voltage

The overflow, underflow and low voltage diagnostic alarm information will be reported in the analog data values even if
the alarms are disabled in the module configuration.

When wire break alarm is disabled and an open wire condition exists in the sensor wiring, the module may report
random values.

The SM 1231 Thermocouple (TC) analog signal module measures the value of voltage
connected to the module inputs. The temperature measurement type can be either
"Thermocouple" or "Voltage".

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A.7 Thermocouple and RTD signal modules (SMs)
● "Thermocouple": The value will be reported in degrees multiplied by ten (for example, 25.3
degrees will be reported as decimal 253).
● "Voltage": The nominal range full scale value will be decimal 27648.
Table A- 93

Wiring diagrams for the thermocouple SMs

SM 1231 AI 4 x TC 16 bit (6ES7 231-5QD30-0XB0

SM 1231 AI 8 x TC bit (6ES7 231-5QF30-0XB0)

① TC 2, 3, 4, and 5 not shown connected for clarity.
Note
Unused analog inputs should be shorted.
The thermocouple unused channels can be deactivated. No error will occur if an unused
channel is deactivated.

A.7.1.1

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A.7 Thermocouple and RTD signal modules (SMs)
Two more thermocouples are formed where the two dissimilar wires are attached to the
signal connector. The connector temperature causes a voltage that adds to the voltage from
the sensor thermocouple. If this voltage is not corrected, then the temperature reported will
deviate from the sensor temperature.
Cold junction compensation is used to compensate for the connector thermocouple.
Thermocouple tables are based on a reference junction temperature, usually zero degrees
Celsius. The cold junction compensation compensates the connector to zero degrees
Celsius. The cold junction compensation restores the voltage added by the connector
thermocouples. The temperature of the module is measured internally, then converted to a
value to be added to the sensor conversion. The corrected sensor conversion is then
linearized using the thermocouple tables.
For optimum operation of the cold junction compensation, the thermocouple module must be
located in a thermally stable environment. Slow variation (less than 0.1° C/minute) in
ambient module temperature is correctly compensated within the module specifications. Air
movement across the module will also cause cold junction compensation errors.
If better cold junction error compensation is needed, an external iso-thermal terminal block
may be used. The thermocouple module provides for use of a 0° C referenced or 50° C
referenced terminal block.

A.7.1.2

Selection tables for the SM 1231 thermocouple
The ranges and accuracy for the different thermocouple types supported by the SM 1231
Thermocouple signal module are shown in the table below.

Table A- 94

SM 1231 Thermocouple selection table

Type

Under-range
minimum1

Nominal range
low limit

Nominal range
high limit

Over-range
maximum2

Normal range 3, 4
accuracy @ 25°C

Normal range 1, 2
accuracy
0°C to 55°C

-210.0°C

-150.0°C

1200.0°C

1450.0°C

±0.3°C

±0.6°C

-270.0°C

-200.0°C

1372.0°C

1622.0°C

±0.4°C

±1.0°C

-270.0°C

-200.0°C

400.0°C

540.0°C

±0.5°C

±1.0°C

-270.0°C

-200.0°C

1000.0°C

1200.0°C

±0.3°C

±0.6°C

R&S

-50.0°C

100.0°C

1768.0°C

2019.0°C

±1.0°C

±2.5°C

-270.0°C

-200.0°C

1300.0°C

1550.0°C

±1.0°C

±1.6°C

0.0°C

100.0°C

2315.0°C

2500.0°C

±0.7°C

±2.7°C

TXK/XK(L)

-200.0°C

-150.0°C

800.0°C

1050.0°C

±0.6°C

±1.2°C

Voltage

-32512

-27648
-80mV

27648
80mV

32511

±0.05%

±0.1%

Thermocouple values below the under-range minimum value are reported as -32768.

Thermocouple values above the over-range minimum value are reported as 32767.

Internal cold junction error is ±1.5°C for all ranges. This adds to the error in this table. The module requires at least 30
minutes of warmup time to meet this specification.

In the presence of radiated radio frequency of 970 MHz to 990 MHz, the accuracy of the SM 1231 AI 4 x 16 bit TC may
be degraded.

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Technical specifications
A.7 Thermocouple and RTD signal modules (SMs)
Table A- 95

Noise reduction and update times for the SM 1231 Thermocouple

Rejection frequency selection

Integration time

4 Channel module update
time (seconds)

8 Channel module update
time (seconds)

400 Hz (2.5 ms)

10 ms 1

0.143

0.285

60 Hz (16.6 ms)

16.67 ms

0.223

0.445

50 Hz (20 ms)

20 ms

0.263

0.525

10 Hz (100 ms)

100 ms

1.225

2.450

To maintain module resolution and accuracy when 400 Hz rejection is selected, the integration time is 10 ms. This
selection also rejects 100 Hz and 200 Hz noise.

It is recommended for measuring thermocouples that a 100 ms integration time be used. The
use of smaller integration times will increase the repeatability error of the temperature
readings.
Note
After power is applied, the module performs internal calibration for the analog-to-digital
converter. During this time the module reports a value of 32767 on each channel until valid
data is available on that channel. Your user program may need to allow for this initialization
time. Because the configuration of the module can vary the length of the initialization time,
you should verify the behavior of the module in your configuration. If required, you can
include logic in your user program to accommodate the initialization time of the module.

A.7.2

SM 1231 RTD

SM 1231 RTD specifications
Table A- 96

General specifications

Technical data

SM 1231 AI 4 x RTD x 16 bit

SM 1231 AI 8 x RTD x 16 bit

Order number

6ES7 231-5PD30-0XB0

6ES7 231-5PF30-0XB0

Dimensions W x H x D (mm)

45 x 100 x 75

70 x 100 x 75

Weight

220 grams

270 grams

Power dissipation

1.5 W

Current consumption (SM Bus)

80 mA

90 mA

Current consumption (24 VDC) 1

40 mA

20.4 to 28.8 VDC (Class 2, Limited Power, or sensor power from CPU)

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A.7 Thermocouple and RTD signal modules (SMs)
Table A- 97

Analog inputs

Technical data

SM 1231 AI 4 x RTD x 16 bit

SM 1231 AI 8 x RTD x16 bit

Number of inputs

Type

Module referenced RTD and Ω

Range

See RTD Sensor selection table
(Page 615).

Temperature

0.1° C/0.1° F

Resistance

15 bits plus sign

Maximum withstand voltage

± 35 V

Noise rejection

85 dB for the selected noise reduction
(10 Hz, 50 Hz, 60 Hz or 400 Hz)

Common mode rejection

> 120dB

Impedance

≥ 10 MΩ

Field side to logic

500 VAC

Field to 24 VDC

500 VAC

24 VDC to logic

500 VAC

Channel to channel isolation

none

Accuracy

See RTD Sensor selection table
(Page 615).

Repeatability

±0.05% FS

Maximum sensor dissipation

0.5m W

Measuring principle

Integrating

Module update time

See Noise reduction selection table
(Page 615).

Cable length (meters)

100 meters to sensor max.

Wire resistance

20 Ω, 2.7 Ω for 10 Ω RTD max.

SM 1231 AI 4 x RTD x 16 bit

SM 1231 AI 8 x RTD x16 bit

Nominal range (data word)
Overshoot/undershoot range
(data word)
Overflow/underflow (data word)
Resolution

Isolation

Table A- 98

Diagnostics

Technical data
Overflow/underflow

Yes

Wire break 3

Yes

24 VDC low voltage 1

Yes

1,2

The overflow, underflow and low voltage diagnostic alarm information will be reported in the analog data values even if
the alarms are disabled in the module configuration.

For resistance ranges underflow detection is never enabled.

When wire break alarm is disabled and an open wire condition exists in the sensor wiring, the module may report
random values.

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Technical specifications
A.7 Thermocouple and RTD signal modules (SMs)
The SM 1231 RTD analog signal module measures the value of resistance connected to the
module inputs. The measurement type can be selected as either "Resistor" or "Thermal
resistor".
● "Resistor": The nominal range full scale value will be decimal 27648.
● "Thermal resistor": The value will be reported in degrees multiplied by ten (for example,
25.3 degrees will be reported as decimal 253).
The SM 1231 RTD module supports measurements with 2-wire, 3-wire and 4-wire
connections to the sensor resistor.
Table A- 99

Wiring diagrams for the RTD SMs

SM 1231 RTD 4 x 16 bit (6ES7 231-5PD30-0XB)

SM 1231 RTD 8 x 16 bit (6ES7 231-5PF30-0XB0)

① Loop-back unused RTD inputs
② 2-wire RTD ③ 3-wire RTD ④ 4-wire RTD
Note
The RTD unused channels can be deactivated. No error will occur if an unused channel is
deactivated.
The RTD module needs to have the current loop continuous to eliminate extra stabilization
time which is automatically added to an unused channel that is not deactivated. For
consistency the RTD module should have a resistor connected (like the 2-wire RTD
connection).

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A.7 Thermocouple and RTD signal modules (SMs)

A.7.2.1

Selection tables for the SM 1231 RTD

Table A- 100 Ranges and accuracy for the different sensors supported by the RTD modules
Temperature
coefficient

RTD type

Under range
minimum1

Nominal
Nominal Over range
range low limit range high maximum2
limit

Normal
range
accuracy
@ 25°C

Normal
range
accuracy
0°C to 55°C

Pt 0.003850

Pt 10

-243.0°C

-200.0°C

850.0°C

1000.0°C

±1.0°C

±2.0°C

ITS90
DIN EN 60751

Pt 50

-243.0°C

-200.0°C

850.0°C

1000.0°C

±0.5°C

±1.0°C

Pt 100

-243.0°C

-200.0°C

850.0°C

1000.0°C

± 0.5°C

±1.0°C

Pt 200

-243.0°C

-200.0°C

850.0°C

1000.0°C

± 0.5°C

±1.0°C

Pt 10

-273.2°C

-240.0°C

1100.0°C

1295°C

±1.0°C

±2.0°C

Pt 50

-273.2°C

-240.0°C

1100.0°C

1295°C

±0.8°C

±1.6°C

-105.0°C

-60.0°C

250.0°C

295.0°C

±0.5°C

±1.0°C

Pt 100
Pt 200
Pt 500
Pt 1000

Pt 0.003902
Pt 0.003916
Pt 0.003920

Pt 500
Pt 1000

Pt 0.003910

Pt 100
Pt 500
Ni 0.006720
Ni 0.006180

Ni 100
Ni 120
Ni 200
Ni 500
Ni 1000

LG-Ni 0.005000

LG-Ni 1000

-105.0°C

-60.0°C

250.0°C

295.0°C

±0.5°C

±1.0°C

Ni 0.006170

Ni 100

-105.0°C

-60.0°C

180.0°C

212.4°C

±0.5°C

±1.0°C

Cu 0.004270

Cu 10

-240.0°C

-200.0°C

260.0°C

312.0°C

±1.0°C

±2.0°C

Cu 0.004260

Cu 10

-60.0°C

-50.0°C

200.0°C

240.0°C

±1.0°C

±2.0°C

Cu 50

-60.0°C

-50.0°C

200.0°C

240.0°C

±0.6°C

±1.2°C

Cu 10

-240.0°C

-200.0°C

200.0°C

240.0°C

±1.0°C

±2.0°C

Cu 50

-240.0°C

-200.0°C

200.0°C

240.0°C

±0.7°C

±1.4°C

Cu 100
Cu 0.004280

Cu 100
1

RTD values below the under-range minimum value report -32768.

RTD values above the over-range minimum value report -32768.

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Technical specifications
A.7 Thermocouple and RTD signal modules (SMs)
Table A- 101 Resistance
Range

Under range
minimum1

Nominal range
low limit

Nominal range
high limit

Over range
maximum2

Normal range
accuracy
@ 25°C

Normal range
accuracy
0°C to 55°C

150 Ω

n/a

0 (0 Ω)

27648 (150 Ω)

176.383 Ω

±0.05%

±0.1%

300 Ω

n/a

0 (0 Ω)

27648 (300 Ω)

352.767 Ω

±0.05%

±0.1%

600 Ω

n/a

0 (0 Ω)

27648 (600 Ω)

705.534 Ω

±0.05%

±0.1%

RTD values below the under-range minimum value are reported as -32768.

RTD values above the over-range minimum value are reported as -32768.

Note
The module reports 32767 on any activated channel with no sensor connected. If open wire
detection is also enabled, the module flashes the appropriate red LEDs.
When 500 Ω and 1000 Ω RTD ranges are used with other lower value resistors, the error
may increase to two times the specified error.
Best accuracy will be achieved for the 10 Ω RTD ranges if 4 wire connections are used.
The resistance of the connection wires in 2 wire mode will cause an error in the sensor
reading and therefore accuracy is not guaranteed.

Table A- 102 Noise reduction and update times for the RTD modules

Rejection frequency
selection

Integration time

400 Hz (2.5 ms)

10 ms 1

Update time (seconds)
4-channel module
4-/2-wire: 0.142

8-channel module

3-wire: 0.285

4-/2-wire: 0.285
3-wire: 0.525

60 Hz (16.6 ms)

16.67 ms

4-/2-wire: 0.222
3-wire: 0.445

4-/2-wire: 0.445
3-wire: 0.845

50 Hz (20 ms)

20 ms

4-/2-wire: 0.262
3-wire: .505

4-/2-wire: 0.524
3-wire: 1.015

10 Hz (100 ms)

100 ms

4-/2-wire: 1.222
3-wire: 2.445

4-/2-wire: 2.425
3-wire: 4.845

To maintain module resolution and accuracy when the 400 Hz filter is selected, the integration time is 10 ms. This
selection also rejects 100 Hz and 200 Hz noise.

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A.8 Digital signal boards (SBs)

NOTICE
After power is applied, the module performs internal calibration for the analog-to-digital
converter. During this time the module reports a value of 32767 on each channel until valid
data is available on that channel. Your user program may need to allow for this initialization
time. Because the configuration of the module can vary the length of the initialization time,
you should verify the behavior or the module in your configuration. If required, you can
include logic in your user program to accommodate the initialization time of the module.

A.8

Digital signal boards (SBs)

A.8.1

SB 1221 200 kHz digital input specifications

Table A- 103 General specifications
Technical data

SB 1221 DI 4 x 24 VDC, 200 kHz

SB 1221 DI 4 x 5 VDC, 200 kHz

Order number

6ES7 221-3BD30-0XB0

6ES7 221-3AD30-0XB0

Dimensions W x H x D (mm)

38 x 62 x 21

Weight

35 grams

Power dissipation

1.5 W

1.0 W

Current consumption (SM Bus)

40 mA

Current consumption (24 VDC)

7 mA / input + 20 mA

15 mA / input + 15 mA

Table A- 104 Digital inputs
Technical data

SB 1221 DI 4 x 24 VDC, 200 kHz

SB 1221 DI 4 x 5 VDC, 200 kHz

Number of inputs

Type

Source

Rated voltage

24 VDC at 7 mA, nominal

5 VDC at 15 mA, nominal

Continuous permissible voltage

28.8 VDC

6 VDC

Surge voltage

35 VDC for 0.5 sec.

Logic 1 signal (min.)

L+ minus 10 VDC at 2.9 mA

L+ minus 2.0 VDC at 5.1 mA

Logic 0 signal (max.)

L+ minus 5 VDC at 1.4 mA

L+ minus 1.0 VDC at 2.2 mA

HSC clock input rates (max.)

Single phase: 200 kHz
Quadrature phase: 160 kHz

Isolation (field side to logic)

500 VAC for 1 minute

Isolation groups

Filter times

0.2, 0.4, 0.8, 1.6, 3.2, 6.4, and 12.8 ms; 0.2, 0.4, 0.8, 1.6, 3.2, 6.4, and 12.8 ms;
Selectable in groups of 4
Selectable in groups of 4

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Technical specifications
A.8 Digital signal boards (SBs)

Technical data

SB 1221 DI 4 x 24 VDC, 200 kHz

SB 1221 DI 4 x 5 VDC, 200 kHz

Number of inputs on simultaneously

Cable length (meters)

50 shielded twisted pair

NOTICE
When switching frequencies above 20 kHz, it is important that the digital inputs receive a
square wave. Consider the following options to improve the signal quality to the inputs:
 Minimize the cable length





Change a driver from a sink only driver to a sinking and sourcing driver
Change to a higher quality cable
Reduce the circuit/components from 24 V to 5 V
Add an external load at the input

Table A- 105 Wiring diagrams for the 200 kHz digital input SBs
SB 1221 DI 4 x 24 VDC, 200 kHz
(6ES7 221-3BD30-0XB0)

SB 1221 DI 4 x 5 VDC, 200 kHz
(6ES7 221-3AD30-0XB0)

① Supports sourcing inputs only

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Technical specifications
A.8 Digital signal boards (SBs)

A.8.2

SB 1222 200 kHz digital output specifications

Table A- 106 General specifications
Technical data

SB 1222 DQ 4 x 24 VDC, 200 kHz

SB 1222 DQ 4 x 5 VDC, 200 kHz

Order number

6ES7 222-1BD30-0XB0

6ES7 222-1AD30-0XB0

Dimensions W x H x D (mm)

38 x 62 x 21

Weight

35 grams

Power dissipation

0.5 W

Current consumption (SM Bus)

35 mA

Current consumption (24 VDC)

15 mA

Technical data

SB 1222 DQ 4 x 24 VDC, 200 kHz

SB 1222 DQ 4 x 5 VDC, 200 kHz

Number of outputs

Output type

Solid state - MOSFET sink and source

Voltage range

20.4 to 28.8 VDC

4.25 to 6.0 VDC

Logic 1 signal at max. current

L+ minus 1.5 V

L+ minus 0.7 V

Logic 0 signal at max. current

1.0 VDC, max.

0.2 VDC, max.

Current (max.)

0.1 A

Lamp load

On state contact resistance

11 Ω max.

7 Ω max.

Table A- 107 Digital outputs

Off state resistance

6 Ω max.

0.2 Ω max.

Leakage current per point

Pulse Train Output rate

200 kHz max., 2 Hz min.

Surge current

0.11 A

Overload protection

Isolation (field side to logic)

500 VAC for 1 minute

Isolation groups

Currents per common

0.4 A

Inductive clamp voltage

None

Switching delay

1.5 μs + 300 ns rise
1.5 μs + 300 ns fall

200 ns + 300 ns rise
200 ns + 300 ns fall

Behavior on RUN to STOP

Last value or substitute value (default
value 0)

Number of outputs on simultaneously

Cable length (meters)

50 shielded twisted pair

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Technical specifications
A.8 Digital signal boards (SBs)

Change a driver from a sink only driver to a sinking and sourcing driver
Change to a higher quality cable
Reduce the circuit/components from 24 V to 5 V
Add an external load at the input

Table A- 108 Wiring diagrams for the 200 kHz digital output SBs
SB 1222 DQ 4 x 24 VDC, 200 kHz
(6ES7 222-1BD30-0XB0)

SB 1222 DQ 4 x 5 VDC, 200 kHz
(6ES7 222-1AD30-0XB0)

① For sourcing outputs, connect "Load" to "-" (shown). For sinking outputs, connect "Load" to "+".

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Technical specifications
A.8 Digital signal boards (SBs)

A.8.3

SB 1223 200 kHz digital input / output specifications

Table A- 109 General specifications
Technical data

SB 1223 DI 2 x 24 VDC /
DQ 2 x 24 VDC, 200 kHz

SB 1223 DI 2 x 5 VDC /
DQ 2 x 5 VDC, 200 kHz

Order number

6ES7 223-3BD30-0XB00

6ES7 223-3AD30-0XB0

Dimensions W x H x D (mm)

38 x 62 x 21

Weight

35 grams

Power dissipation

1.0 W

0.5 W

Current consumption (SM Bus)

35 mA

Current consumption (24 VDC)

7 mA / Input + 30 mA

15 mA / input + 15 mA

Technical data

SB 1223 DI 2 x 24 VDC /
DQ 2 x 24 VDC, 200 kHz

SB 1223 DI 2 x 5 VDC /
DQ 2 x 5 VDC, 200 kHz

Number of inputs

Type

Source

Rated voltage

24 VDC at 7 mA, nominal

5 VDC at 15 mA, nominal

Continuous permissible voltage

28.8 VDC

6 VDC

Surge voltage

35 VDC for 0.5 sec.

Logic 1 signal (min.)

L+ minus 10 VDC at 2.9 mA

L+ minus 2.0 VDC at 5.1 mA

Logic 0 signal (max.)

L+ minus 5 VDC at 1.4 mA

L+ minus 1.0 VDC at 2.2 mA

HSC clock input rates (max.)

Single phase: 200 kHz
Quadrature phase: 160 kHz

Isolation (field side to logic)

500 VAC for 1 minute

Isolation groups

1 (no isolation to outputs)

Filter times

0.2, 0.4, 0.8, 1.6, 3.2, 6.4, and 12.8 ms; 0.2, 0.4, 0.8, 1.6, 3.2, 6.4, and 12.8 ms;
Selectable in groups of 4
Selectable in groups of 4

Number of inputs on simultaneously

Cable length (meters)

50 shielded twisted pair

Technical data

SB 1223 DI 2 x 24 VDC /
DQ 2 x 24 VDC, 200 kHz

SB 1223 DI 2 x 5 VDC /
DQ 2 x 5 VDC, 200 kHz

Number of outputs

Output type

Solid state - MOSFET sink and source

Voltage range

20.4 to 28.8 VDC

4.25 to 6.0 VDC

Rated value

24 VDC

5 VDC

Logic 1 signal at max. current

L+ minus 1.5 V

L+ minus 0.7 V

Logic 0 signal at max. current

1.0 VDC, max.

0.2 VDC, max.

Table A- 110 Digital inputs

Table A- 111 Digital outputs

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Technical specifications
A.8 Digital signal boards (SBs)

Technical data

SB 1223 DI 2 x 24 VDC /
DQ 2 x 24 VDC, 200 kHz

SB 1223 DI 2 x 5 VDC /
DQ 2 x 5 VDC, 200 kHz

Current (max.)

0.1 A

Lamp load

On state contact resistance

11 Ω max.

7 Ω max.

Off state resistance

6 Ω max.

0.2 Ω max.

Leakage current per point

Pulse Train Output rate

200 kHz max., 2 Hz min.

Surge current

0.11 A

Overload protection

Isolation (field side to logic)

500 VAC for 1 minute

Isolation groups

1 (no isolation to inputs)

Currents per common

0.2 A

Inductive clamp voltage

None

Switching delay

1.5 μs + 300 ns rise
1.5 μs + 300 ns fall

200 ns + 300 ns rise
200 ns + 300 ns fall

Behavior on RUN to STOP

Last value or substitute
(default value 0)

Number of outputs on simultaneously

Cable length (meters)

50 shielded twisted pair

Change a driver from a sink only driver to a sinking and sourcing driver
Change to a higher quality cable
Reduce the circuit/components from 24 V to 5 V
Add an external load at the input

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Technical specifications
A.8 Digital signal boards (SBs)
Table A- 112 Wiring diagrams for the 200 kHz digital input/output SBs
SB 1223 DI 2 x 24 VDC/DQ 2 x 24 VDC,
200 kHz (6ES7 223-3BD30-0XB0)

SB 1223 DI 2 x 5 VDC / DQ 2 x 5 VDC,
200 kHz (6ES7 223-3AD30-0XB0)

① Supports sourcing inputs only
② For sourcing outputs, connect "Load" to "-" (shown). For sinking outputs, connect "Load" to "+".

A.8.4

SB 1223 2 X 24 VDC input / 2 X 24 VDC output specifications

Table A- 113 General specifications
Technical Data

SB 1223 DI 2 x 24 VDC, DQ 2 x 24 VDC

Order number

6ES7 223-0BD30-0XB0

Dimensions W x H x D (mm)

38 x 62 x 21

Weight

40 grams

Power dissipation

1.0 W

Current consumption (SM Bus)

50 mA

Current consumption (24 VDC)

4 mA / Input used

Table A- 114 Digital inputs
Technical Data

SB 1223 DI 2 x 24 VDC, DQ 2 x 24 VDC

Number of inputs

Type

IEC Type 1 sink

Rated voltage

24 VDC at 4 mA, nominal

Continuous permissible voltage

30 VDC, max.

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A.8 Digital signal boards (SBs)

Technical Data

SB 1223 DI 2 x 24 VDC, DQ 2 x 24 VDC

Surge voltage

35 VDC for 0.5 sec.

Logic 1 signal (min.)

15 VDC at 2.5 mA

Logic 0 signal (max.)

5 VDC at 1 mA

HSC clock input rates (max.)

20 kHz (15 to 30 VDC)
30 kHz (15 to 26 VDC)

Isolation (field side to logic)

500 VAC for 1 minute

Isolation groups

Filter times

0.2, 0.4, 0.8, 1.6, 3.2, 6.4, and 12.8 ms
Selectable in groups of 2

Number of inputs on simultaneously

Cable length (meters)

500 shielded, 300 unshielded

Table A- 115 Digital outputs

Technical Data

SB 1223 DI 2 x 24 VDC, DQ 2 x 24 VDC

Number of outputs

Output type

Solid state - MOSFET (sourcing)

Voltage range

20.4 to 28.8 VDC

Logic 1 signal at max. current

20 VDC min.

Logic 0 signal with 10K Ω load

0.1 VDC max.

Current (max.)

0.5 A

Lamp load

On state contact resistance

0.6 Ω max.

Leakage current per point

10 μA max.

Pulse Train Output (PTO) rate

20 KHz max., 2 Hz min. 1

Surge current

5 A for 100 ms max.

Overload protection

Isolation (field side to logic)

500 VAC for 1 minute

Isolation groups

Currents per common

Inductive clamp voltage

L+ minus 48 V, 1 W dissipation

Switching delay

2 μs max. off to on
10 μs max. on to off

Behavior on RUN to STOP

Last value or substitute value (default value 0)

Number of outputs on simultaneously

Cable length (meters)

500 m shielded, 150 m unshielded

Depending on your pulse receiver and cable, an additional load resistor (at least 10% of rated current) may improve
pulse signal quality and noise immunity.

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Technical specifications
A.9 Analog signal boards (SBs)
Table A- 116 Wiring diagram for the digital input/output SB
SB 1223 DI 2 x 24 VDC, DQ 2 x 24 VDC (6ES7 223-0BD30-0XB0)

① Supports sinking inputs only

A.9

Analog signal boards (SBs)

A.9.1

SB 1231 1 analog input specifications
Note
To use this SB, your CPU firmware must be V2.0 or higher.

Table A- 117 General specifications
Technical data

SB 1231 AI 1 x 12 bit

Order number

6ES7 231-4HA30-0XB0

Dimensions W x H x D (mm)

38 x 62 x 21 mm

Weight

35 grams

Power dissipation

0.4 W

Current consumption (SM Bus)

55 mA

Current consumption (24 VDC)

none

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Technical specifications
A.9 Analog signal boards (SBs)
Table A- 118 Analog inputs
Technical data

SB 1231 AI 1x12 bit

Number of inputs

Type

Voltage or current (differential)

Range

±10V, ±5V, ±2.5 or 0 to 20 mA

Resolution

11 bits + sign bit

Full scale range (data word)

-27,648 to 27,648

Over/Under range (data word)

Voltage: 32,511 to 27,649 / -27,649 to -32,512
Current: 32,511 to 27,649 / 0 to -4,864
(Refer to Analog input representation for voltage and Analog input
representation for current (Page 630).)

Overflow/Underflow (data word)

Voltage: 32,767 to 32,512 / -32,513 to -32,768
Current: 32,767 to 32,512 / -4,865 to -32,768
(Refer to Analog input representation for voltage and Analog input
representation for current (Page 630).)

Maximum withstand voltage / current

±35V / ±40 mA

Smoothing

None, weak, medium, or strong (refer to Analog input response
times for step response time (Page 630).)

Noise rejection

400, 60, 50, or 10 Hz (refer to Analog input response times for
sample rates (Page 630).)

Accuracy (25°C / 0 to 55°C)

±0.3% / ±0.6% of full scale

Load impedance
Differential
Common mode

Voltage: 220 kΩ; Current: 250 Ω
Voltage: 55 kΩ; Current: 55 kΩ

Behavior on RUN to STOP

Last value or substitute value (default value 0)

Measuring principle

Actual value conversion

Common mode rejection

400 dB, DC to 60 Hz

Operational signal range

Signal plus common mode voltage must be less than +35 V and
greater than -35 V

Isolation (field side to logic)

None

Cable length (meters)

100 m, twisted and shielded

Table A- 119 Diagnostics
Technical data

SB 1231 AI 1 x 12 bit

Overflow/underflow

Yes

24 VDC low voltage

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Technical specifications
A.9 Analog signal boards (SBs)
Table A- 120 Wiring diagram for the analog input SB
SB 1231 AI x 12 bit (6ES7 231-4HA30-0XB0)

① Connect "R" and "0+" for current

A.9.2

SB 1232 1 analog output specifications

Table A- 121 General specifications
Technical data

SB 1232 AQ 1 x 12 bit

Order number

6ES7 232-4HA30-0XB0

Dimensions W x H x D (mm)

38 x 62 x 21 mm

Weight

40 grams

Power dissipation

1.5 W

Current consumption (SM Bus)

15 mA

Current consumption (24 VDC)

40 mA (no load)

Table A- 122 Analog outputs
Technical data

SB 1232 AQ 1 x 12 bit

Number of outputs

Type

Voltage or current

Range

±10 V or 0 to 20 mA

Resolution

Voltage: 12 bits
Current: 11 bits

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Technical specifications
A.9 Analog signal boards (SBs)

Technical data

SB 1232 AQ 1 x 12 bit

Full scale range (data word)

Voltage: -27,648 to 27,648

Refer to the output ranges for voltage and current
(Page 630).

Current: 0 to 27,648

Accuracy (25°C / 0 to 55°C)

±0.5% / ±1% of full scale

Settling time (95% of new value)

Voltage: 300 μS (R), 750 μS (1 uF)
Current: 600 μS (1 mH), 2 ms (10 mH)

Load impedance

Voltage: ≥ 1000 Ω
Current: ≤ 600 Ω

Behavior on RUN to STOP

Last value or substitute value (default value 0)

Isolation (field side to logic)

None

Cable length (meters)

100 m, twisted and shielded

Table A- 123 Diagnostics
Technical data

SB 1232 AQ 1 x 12 bit

Overflow/underflow

Yes

Short to ground (voltage mode only)

Yes

Wire break (current mode only)

Yes

Table A- 124 Wiring diagram for the analog output SB
SB 1232 AQ 1 x 12 bit (6ES7 232-4HA30-0XB0)

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Technical specifications
A.9 Analog signal boards (SBs)

A.9.3

Measurement ranges for analog inputs and outputs

A.9.3.1

Step response of the analog inputs

Table A- 125 Step response (ms), 0V to 10V measured at 95%
Smoothing selection (sample averaging)

Integration time selection
400 Hz (2.5 ms)

60 Hz (16.6 ms)

50 Hz (20 ms)

10 Hz (100 ms)

None (1 cycle): No averaging

4.5 ms

18.7 ms

22.0 ms

102 ms

Weak (4 cycles): 4 samples

10.6 ms

59.3 ms

70.8 ms

346 ms

Medium (16 cycles): 16 samples

33.0 ms

208 ms

250 ms

1240 ms

Strong (32 cycles): 32 samples

63.0 ms

408 ms

490 ms

2440 ms

Sample time

0.156 ms

1.042 ms

1.250 ms

6.250 ms

A.9.3.2

Sample time and update times for the analog inputs

Table A- 126 Sample time and update time
Selection

Sample time

SB update time

400 Hz (2.5 ms)

0.156 ms

60 Hz (16.6 ms)

1.042 ms

50 Hz (20 ms)

1.250 ms

1.25 ms

10 Hz (100 ms)

6.250 ms

6.25 ms

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Technical specifications
A.9 Analog signal boards (SBs)

A.9.3.3

Measurement ranges of the analog inputs for voltage

Table A- 127 Analog input representation for voltage
System

Voltage Measuring Range

Decimal

Hexadecimal

±10 V

±5 V

±2.5 V

32767

7FFF

11.851 V

5.926 V

2.963 V

Overflow

11.851 V

Overflow

32512

7F00
11.759 V

5.879 V

2.940 V

Overshoot range

11.759 V

Overshoot
range

10 V

2.5 V

Rated range

10 V

Rated range

32511

7EFF

27649

6C01

27648

6C00

0 to 10 V

20736

5100

7.5 V

3.75 V

1.875 V

7.5 V

361.7 μV

180.8 μV

90.4 μV

361.7 μV

-1

FFFF

-20736

AF00

-7.5 V

-3.75 V

-1.875 V

-27648

9400

-10 V

-5 V

-2.5 V

Negative
values are not
supported

-27649

93FF

-32512

8100

-32513

80FF

-32768

8000

A.9.3.4

Undershoot range
-11.759 V

-5.879 V

-2.940 V
Underflow

-11.851 V

-5.926 V

-2.963 V

Output (AQ) measurement ranges for voltage and current (SB and SM)

Table A- 128 Analog output representation for current
System

Current Output Range

Decimal

Hexadecimal

0 mA to 20 mA

32767

7FFF

See note 1

32512

7F00

See note 1

32511

7EFF

23.52 mA

Overshoot range

27649

6C01
Rated range

27648

6C00

20 mA

20736

5100

15 mA

723.4 nA

0 mA

Overflow

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Technical specifications
A.9 Analog signal boards (SBs)
Table A- 129 Analog output representation for voltage
System

Voltage Output Range

Decimal

Hexadecimal

± 10 V

32767

7FFF

See note 1

32512

7F00

See note 1

32511

7EFF

11.76 V

Overshoot range

27649

6C01

27648

6C00

10 V

Rated range

20736

5100

7.5 V

361.7 μ V

-1

FFFF

-361.7 μ V

-20736

AF00

-7.5 V

-27648

9400

-10 V

-27649

93FF

-32512

8100

-11.76 V

-32513

80FF

See note 1

-32768

8000

See note 1

Overflow

Undershoot range
Underflow

A.9.4

Thermocouple SBs

A.9.4.1

SB 1231 1 analog thermocouple input specifications
Note
To use this SB, your CPU firmware must be V2.0 or higher.

Table A- 130 General specifications
Technical data

SB 1231 AI 1 x 16 bit Thermocouple

Order number

6ES7 231-5QA30-0XB0

Dimensions W x H x D (mm)

38 x 62 x 21 mm

Weight

35 grams

Power dissipation

0.5 W

Current consumption (SM Bus)

5 mA

Current consumption (24 VDC)

20 mA

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Technical specifications
A.9 Analog signal boards (SBs)
Table A- 131 Analog inputs
Technical data

SB 1231 AI 1x16 bit Thermocouple

Number of inputs

Type

Floating TC and mV

Range

See Thermocouple filter selection table (Page 633).



Nominal range (data word)



Overrange/underrange (data word)



Overflow/underflow (data word)

Resolution

Temperature

0.1° C / 0.1° F

Voltage

15 bits plus sign

Maximum withstand voltage

±35 V

Noise rejection

85 dB for the selected filter setting
(10 Hz, 50 Hz, 60 Hz, 400 Hz)

Common mode rejection

> 120 dB at 120 VAC

Impedance

≥ 10 M Ω

Accuracy (25°C / 0 to 55°C)

See Thermocouple selection table (Page 633).

Repeatability

±0.05% FS

Measuring principle

Integrating

Module update time

See Thermocouple filter selection table (Page 633).

Cold junction error

±1.5° C

Isolation (field side to logic)

500 VAC

Cable length (meters)

100 m to sensor max.

Wire resistance

100 Ω max.

Table A- 132 Diagnostics
Technical data

SB 1231 AI 1 x 16 bit Thermocouple

Overflow/underflow1

Yes

Wire break2

Yes

The overflow and underflow diagnostic alarm information will be reported in the analog data values even if the alarms
are disabled in the module configuration.

When wire break alarm is disabled and an open wire condition exists in the sensor wiring, the module may report
random values.

The SM 1231 Thermocouple (TC) analog signal module measures the value of voltage
connected to the module inputs.
The SB 1231 Thermocouple analog signal board measures the value of voltage connected
to the signal board inputs. The temperature measurement type can be either
"Thermocouple" or "Voltage".
● "Thermocouple": The value will be reported in degrees multiplied by ten (for example,
25.3 degrees will be reported as decimal 253).
● "Voltage": The nominal range full scale value will be decimal 27648.

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Technical specifications
A.9 Analog signal boards (SBs)

A.9.4.2

Basic operation for a thermocouple
Thermocouples are formed whenever two dissimilar metals are electrically bonded to each
other. A voltage is generated that is proportional to the junction temperature. This voltage is
small; one microvolt could represent many degrees. Measuring the voltage from a
thermocouple, compensating for extra junctions, and then linearizing the result forms the
basis of temperature measurement using thermocouples.
When you connect a thermocouple to the SB 1231 Thermocouple signal board, the two
dissimilar metal wires are attached to the module at the module signal connector. The place
where the two dissimilar wires are attached to each other forms the sensor thermocouple.
Two more thermocouples are formed where the two dissimilar wires are attached to the
signal connector. The connector temperature causes a voltage that adds to the voltage from
the sensor thermocouple. If this voltage is not corrected, then the temperature reported will
deviate from the sensor temperature.
Cold junction compensation is used to compensate for the connector thermocouple.
Thermocouple tables are based on a reference junction temperature, usually zero degrees
Celsius. The cold junction compensation compensates the connector to zero degrees
Celsius. The cold junction compensation restores the voltage added by the connector
thermocouples. The temperature of the module is measured internally, then converted to a
value to be added to the sensor conversion. The corrected sensor conversion is then
linearized using the thermocouple tables.
For optimum operation of the cold junction compensation, the thermocouple module must be
located in a thermally stable environment. Slow variation (less than 0.1° C/minute) in
ambient module temperature is correctly compensated within the module specifications. Air
movement across the module will also cause cold junction compensation errors.
If better cold junction error compensation is needed, an external iso-thermal terminal block
may be used. The thermocouple module provides for use of a 0° C referenced or 50° C
referenced terminal block.

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Technical specifications
A.9 Analog signal boards (SBs)

Selection table for the SB 1231 thermocouple
The ranges and accuracy for the different thermocouple types supported by the SB 1231
Thermocouple signal board are shown in the table below.
Table A- 133 SB 1231 Thermocouple selection table
Thermocouple
Type

Under range
minimum1

Nominal
Nominal range
range low limit high limit

-210.0°C

-150.0°C

1200.0°C

1450.0°C

±0.3°C

±0.6°C

-270.0°C

-200.0°C

1372.0°C

1622.0°C

±0.4°C

±1.0°C

-270.0°C

-200.0°C

400.0°C

540.0°C

±0.5°C

±1.0°C

Over range
maximum2

Normal range 3
accuracy @ 25°C

Normal range 3,
accuracy
0°C to 55°C

-270.0°C

-200.0°C

1000.0°C

1200.0°C

±0.3°C

±0.6°C

R&S

-50.0°C

100.0°C

1768.0°C

2019.0°C

±1.0°C

±2.5°C

-270.0°C

0.0°C

1300.0°C

1550.0°C

±1.0°C

±1.6°C

0.0°C

100.0°C

2315.0°C

2500.0°C

±0.7°C

±2.7°C

TXK/XK(L)

-200.0°C

-150.0°C

800.0°C

1050.0°C

±0.6°C

±1.2°C

Voltage

-32511

-27648
-80mV

27648
80mV

32511

±0.05%

±0.1%

Thermocouple values below the under-range minimum value are reported as -32768.

Thermocouple values above the over-range minimum value are reported as 32767.

Internal cold junction error is ±1.5°C for all ranges. This adds to the error in this table. The signal board requires at least
30 minutes of warmup time to meet this specification.

Table A- 134 Filter selection table for the SB 1231 Thermocouple

Rejection frequency (Hz)

Integration time (ms)

Signal board update time (seconds)

100

0.306

0.066

16.67

0.056

4001

0.036

To maintain module resolution and accuracy when 400 Hz rejection is selected, the integration time is 10 ms. This
selection also rejects 100 Hz and 200 Hz noise.

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Technical specifications
A.9 Analog signal boards (SBs)
Table A- 135 Wiring diagram for the analog input thermocouple SB
SB 1231 AI 1 x 16 bit thermocouple (6ES7 231-5QA30-0XB0)

A.9.5

RTD SBs

A.9.5.1

SB 1231 1 analog RTD input specifications
Note
To use this SB, your CPU firmware must be V2.0 or higher.

Table A- 136 General specifications
Technical data

SB 1231 AI 1 x 16 bit RTD

Order number

6ES7 231-5PA30-0XB0

Dimensions W x H x D (mm)

38 x 62 x 21 mm

Weight

35 grams

Power dissipation

0.7 W

Current consumption (SM Bus)

5 mA

Current consumption (24 VDC)

25 mA

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Technical specifications
A.9 Analog signal boards (SBs)
Table A- 137 Analog inputs
Technical data

SB 1231 AI 1 x 16 bit RTD

Number of inputs

Type

Module referenced RTD and Ohms

Range

See Selection tables (Page 637).



Nominal range (data word)



Overrange/underrange (data word)



Overflow/underflow (data word)

Resolution

Temperature

0.1° C/ 0.1° F

Voltage

15 bits plus sign

Maximum withstand voltage

±35 V

Noise rejection

85 dB (10 Hz, 50 Hz, 60 Hz, 400 Hz)

Common mode rejection

> 120 dB

Impedance

≥ 10 MΩ

Accuracy (25°C / 0 to 55°C)

See Selection tables (Page 637).

Repeatability

±0.05% FS

Maximum sensor dissipation

0.5 m W

Measuring principle

Integrating

Module update time

See Selection table (Page 637).

Isolation (field side to logic)

500 VAC

Cable length (meters)

100 m to sensor max.

Wire resistance

20 Ω, 2.7 for 10 Ω RTD max.

Table A- 138 Diagnostics
Technical data

SB 1231 AI 1 x 16 bit RTD

Overflow/underflow1, 2

Yes

Wire break

Yes

The overflow and underflow diagnostic alarm information will be reported in the analog data values even if the alarms
are disabled in the module configuration.

For resistance ranges underflow detection is never enabled.

When wire break alarm is disabled and an open wire condition exists in the sensor wiring, the module may report
random values.

The SM 1231 RTD analog signal board measures the value of resistance connected to the
signal board inputs. The measurement type can be selected as either "Resistor" or "Thermal
resistor".
● "Resistor": The nominal range full scale value will be decimal 27648.
● "Thermal resistor": The value will be reported in degrees multiplied by ten (for example,
25.3 degrees will be reported as decimal 253).
The SB 1231 RTD signal board supports measurements with 2-wire, 3-wire and 4-wire
connections to the sensor resistor.

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A.9 Analog signal boards (SBs)
Table A- 139 Wiring diagram for SB 1231 AI 1 x 16 bit RTD
SB 1213 AI 1 x 16 bit RTD (6ES7 231-5PA30-0XB0)

AI0 -

① Loop-back unused RTD input
② 2-wire RTD
③ 3-wire RTD
④ 4-wire RTD

A.9.5.2

Selection tables for the SB 1231 RTD

Table A- 140 Ranges and accuracy for the different sensors supported by the RTD modules
Temperature
coefficient

RTD type

Under range
minimum1

Nominal
range
low limit

Nominal
range
high limit

Over range
maximum2

Normal
Normal
range
range
accuracy @ accuracy
0°C to 55°C
25°C

Pt 0.003850

Pt 10

-243.0°C

-200.0°C

850.0°C

1000.0°C

±1.0°C

±2.0°C

ITS90
DIN EN 60751

Pt 50

-243.0°C

-200.0°C

850.0°C

1000.0°C

±0.5°C

±1.0°C

-243.0°C

-200.0°C

850.0°C

1000.0°C

± 0.5°C

±1.0°C

Pt 100
Pt 200
Pt 500
Pt 1000

Pt 0.003902
Pt 0.003916
Pt 0.003920

Pt 100
Pt 200
Pt 500
Pt 1000

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Technical specifications
A.9 Analog signal boards (SBs)

Temperature
coefficient

RTD type

Pt 0.003910

Under range
minimum1

Nominal
range
low limit

Nominal
range
high limit

Over range
maximum2

Normal
Normal
range
range
accuracy @ accuracy
0°C to 55°C
25°C

Pt 10

-273.2°C

-240.0°C

1100.0°C

1295°C

±1.0°C

±2.0°C

Pt 50

-273.2°C

-240.0°C

1100.0°C

1295°C

±0.8°C

±1.6°C

-105.0°C

-60.0°C

250.0°C

295.0°C

±0.5°C

±1.0°C

-60.0°C

250.0°C

295.0°C

±0.5°C

±1.0°C

Pt 100
Pt 500
Ni 0.006720
Ni 0.006180

Ni 100
Ni 120
Ni 200
Ni 500
Ni 1000

LG-Ni 0.005000

LG-Ni 1000

-105.0°C

Ni 0.006170

Ni 100

-105.0°C

-60.0°C

180.0°C

212.4°C

±0.5°C

±1.0°C

Cu 0.004270

Cu 10

-240.0°C

-200.0°C

260.0°C

312.0°C

±1.0°C

±2.0°C

Cu 0.004260

Cu 10

-60.0°C

-50.0°C

200.0°C

240.0°C

±1.0°C

±2.0°C

Cu 50

-60.0°C

-50.0°C

200.0°C

240.0°C

±0.6°C

±1.2°C

Cu 10

-240.0°C

-200.0°C

200.0°C

240.0°C

±1.0°C

±2.0°C

Cu 50

-240.0°C

-200.0°C

200.0°C

240.0°C

±0.7°C

±1.4°C

Cu 100
Cu 0.004280

Cu 100
1

RTD values below the under-range minimum value are reported as -32768.

RTD values above the over-range minimum value are reported as -32768.

Table A- 141 Resistance
Range

Under range
minimum

Nominal range
low limit

Nominal range
high limit

Over range
maximum1

Normal range
accuracy
@ 25°C

Normal range
accuracy
0°C to 55°C

150 Ω

n/a

0 (0 Ω)

27648 (150 Ω)

176.383 Ω

±0.05%

±0.1%

300 Ω

n/a

0 (0 Ω)

27648 (300 Ω)

352.767 Ω

±0.05%

±0.1%

600 Ω

n/a

0 (0 Ω)

27648 (600 Ω)

705.534 Ω

±0.05%

±0.1%

RTD values above the over-range minimum value are reported as -32768.

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A.9 Analog signal boards (SBs)

Table A- 142 Noise reduction and update times for the RTD modules

Rejection frequency
selection

Integration time

400 Hz (2.5 ms)

10 ms 1

60 Hz (16.6 ms)

16.67 ms

4-/2-wire, 1-channel module

3-wire, 1-channel module

Update time (seconds)

0.036

0.071

0.056

0.111

50 Hz (20 ms)

20 ms

0.066

1.086

10 Hz (100 ms)

100 ms

0.306

0.611

To maintain module resolution and accuracy when the 400 Hz filter is selected, the integration time is 10 ms. This
selection also rejects 100 Hz and 200 Hz noise.

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Technical specifications
A.10 Communication interfaces

A.10

Communication interfaces

A.10.1

PROFIBUS
Note
S7-1200 PROFIBUS CMs and the GPRS CP are not approved for Maritime applications
The following modules do not have Maritime approval:
 CM 1242-5 PROFIBUS Slave module
 CM 1243-5 PROFIBUS Master module
 CP 1242-7 GPRS module

Note
To use these modules, your CPU firmware must be V2.0 or higher.

A.10.1.1

CM 1242-5

Table A- 143 Technical specifications of the CM 1242-5
Technical specifications
Order number

6GK7 242-5DX30-0XE0

Interfaces
Connection to PROFIBUS

9-pin D-sub female connector

Maximum current consumption on the PROFIBUS interface
when network components are connected (for example
optical network components)

15 mA at 5 V (only for bus termination) *)

Permitted ambient conditions
Ambient temperature


during storage



-40 °C to 70 °C



during transportation



-40 °C to 70 °C



during operation with a vertical installation (DIN rail
horizontal)



0 °C to 55 °C



during operation with a horizontal installation (DIN rail
vertical)



0 °C to 45 °C

Relative humidity at 25 °C during operation, without
condensation, maximum

95 %

Degree of protection

IP20

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A.10 Communication interfaces

Technical specifications
Power supply, current consumption and power loss
Type of power supply

Power supply from the backplane bus

Current consumption (typical)

150 mA

Effective power loss (typical)

0.75 W

Dimensions and weights


Width



30 mm



Height



100 mm



Depth



75 mm

Weight


Net weight



115 g



Weight including packaging



152 g

*)The current load of an external consumer connected between VP (pin 6) and DGND (pin 5) must not exceed a maximum
of 15 mA (short-circuit proof) for bus termination.

PROFIBUS interface
Table A- 144 Pinout of the D-sub socket
Pin

Description

- not used -

P5V2: +5V power supply

- not used -

RxD/TxD-P: Data line B

RxD/TxD-N: Data line A

RTS

- not used -

M5V2: Data reference potential
(ground DGND)

A.10.1.2

Housing

Ground connector

CM 1243-5

Table A- 145 Technical specifications of the CM 1243-5
Technical specifications
Order number

6GK7 243-5DX30-0XE0

Interfaces
Connection to PROFIBUS

9-pin D-sub female connector

Maximum current consumption on the PROFIBUS interface
when network components are connected (for example
optical network components)

15 mA at 5 V (only for bus termination) *)

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Technical specifications
A.10 Communication interfaces

Technical specifications
Permitted ambient conditions
Ambient temperature


during storage



-40 °C to 70 °C



during transportation



-40 °C to 70 °C



during operation with a vertical installation (DIN rail
horizontal)



0 °C to 55 °C



during operation with a horizontal installation (DIN rail
vertical)



0 °C to 45 °C

Relative humidity at 25 °C during operation, without
condensation, maximum

95 %

Degree of protection

IP20

Power supply, current consumption and power loss
Type of power supply

Power supply / external

24 V



minimum



19.2 V



maximum



28.8 V

Current consumption (typical)


from 24 V DC



100 mA



from the S7-1200 backplane bus



0 mA

Effective power loss (typical)


from 24 V DC



2.4 W



from the S7-1200 backplane bus



Power supply 24 VDC / external


Min. cable cross section



min.: 0.14 mm2 (AWG 25)



Max. cable cross section



max.: 1.5 mm2 (AWG 15)



Tightening torque of the screw terminals



0.45 Nm (4 lb-in)

Dimensions and weights


Width



30 mm



Height



100 mm



Depth



75 mm

Weight


Net weight



134 g



Weight including packaging



171 g

*)The current load of an external consumer connected between VP (pin 6) and DGND (pin 5) must not exceed a maximum
of 15 mA (short-circuit proof) for bus termination.

Note
The CM 1243-5 (PROFIBUS master module) must receive power from the 24 VDC sensor
supply of the CPU.

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A.10 Communication interfaces

PROFIBUS interface
Table A- 146 Pinout of the D-sub socket
Pin

Description

- not used -

VP: Power supply +5 V only for bus
terminating resistors;
not for supplying external devices

- not used -

RxD/TxD-P: Data line B

RxD/TxD-N: Data line A

CNTR-P: RTS

- not used -

DGND: Ground for data signals
and VP

Description

Housing

Ground connector

PROFIBUS cable
NOTICE
Contacting the shield of the PROFIBUS cable
The shield of the PROFIBUS cable must be contacted.
To do this, strip the insulation from the end of the PROFIBUS cable and connect the shield
to functional earth.

A.10.2

GPRS
Note
S7-1200 PROFIBUS CMs and the GPRS CP are not approved for Maritime applications
The following modules do not have Maritime approval:
 CM 1242-5 PROFIBUS Slave module
 CM 1243-5 PROFIBUS Master module
 CP 1242-7 GPRS module

Note
To use these modules, your CPU firmware must be V2.0 or higher.

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Technical specifications
A.10 Communication interfaces

A.10.2.1

CP 1242-7

Table A- 147 Technical specifications of the CP 1242-7
Technical specifications
Order number

6GK7 242-7KX30-0XE0

Wireless interface
Antenna connector

SMA socket

Nominal impedance

50 ohms

Wireless connection
Maximum transmit power



GSM 850, class 4: +33 dBm ±2dBm



GSM 900, class 4: +33 dBm ±2dBm



GSM 1800, class 1: +30 dBm ±2dBm



GSM 1900, class 1: +30 dBm ±2dBm

GPRS

Multislot class 10
device class B
coding scheme 1...4 (GMSK)

SMS

Mode outgoing: MO
service: point-to-point

Permitted ambient conditions
Ambient temperature


during storage



-40 °C to 70 °C



during transportation



-40 °C to 70 °C



during operation with a vertical installation (DIN rail
horizontal)



0 °C to 55 °C



during operation with a horizontal installation (DIN rail
vertical)



0 °C to 45 °C

Relative humidity at 25 °C during operation, without
condensation, maximum

95 %

Degree of protection

IP20

Power supply, current consumption and power loss
Type of power supply

Power supply / external

24 V



minimum



19.2 V



maximum



28.8 V

Current consumption (typical)


from 24 V DC



100 mA



from the S7-1200 backplane bus



0 mA

Effective power loss (typical)


from 24 V DC



2.4 W



from the S7-1200 backplane bus



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A.10 Communication interfaces

Technical specifications
24 V DC power supply


Min. cable cross section



min.: 0.14 mm2 (AWG 25)



Max. cable cross section



max.: 1.5 mm2 (AWG 15)



Tightening torque of the screw terminals



0.45 Nm (4 lb-in)

Dimensions and weights


Width



30 mm



Height



100 mm



Depth



75 mm

Weight


Net weight



133 g



Weight including packaging



170 g

Technical specifications of the ANT794-4MR GSM/GPRS antenna
ANT794-4MR
Order number

6NH9860-1AA00

Mobile wireless networks

GSM/GPRS

Frequency ranges



824 to 960 MHz (GSM 850, 900)



1 710 to 1 880 MHz (GSM 1 800)



1 900 to 2 200 MHz (GSM / UMTS)

Characteristics

omnidirectional

Antenna gain

0 dB

Impedance

50 ohms

Standing wave ratio (SWR)

< 2,0

Max. power

20 W

Polarity

linear vertical

Connector

SMA

Length of antenna cable

External material

Hard PVC, UV-resistant

Degree of protection

IP20

Permitted ambient conditions


Operating temperature



-40 °C through +70 °C



Transport/storage temperature



-40 °C through +70 °C



Relative humidity



100 %

External material

Hard PVC, UV-resistant

Construction

Antenna with 5 m fixed cable and SMA male
connector

Dimensions (D x H) in mm

25 x 193

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Technical specifications
A.10 Communication interfaces

ANT794-4MR
Weight


Antenna incl. cable



310 g



Fittings



54 g

Installation

With supplied bracket

Technical specifications of the flat antenna ANT794-3M
Order number

6NH9870-1AA00

Mobile wireless networks

GSM 900

GSM 1800/1900

Frequency ranges

890 - 960 MHz

1710 - 1990 MHz

Standing wave ratio (VSWR)

≤ 2:1

≤ 1,5:1

Return loss (Tx)

≈ 10 dB

≈ 14 dB

Antenna gain

0 dB

Impedance

50 ohms

Max. power

10 W

Antenna cable

HF cable RG 174 (fixed) with SMA male connector

Cable length

1.2 m

Degree of protection

IP64

Permitted temperature range

-40°C to +75°C

Flammability

UL 94 V2

External material

ABS Polylac PA-765, light gray (RAL 7035)

Dimensions (W x L x H) in mm

70.5 x 146.5 x 20.5

Weight

130 g

A.10.3

RS232 and RS485

A.10.3.1

CB 1241 RS485 Specifications
Note
To use this CB, your CPU firmware must be V2.0 or higher.

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A.10 Communication interfaces
Table A- 148 General specifications
Technical data

CB 1241 RS485

Order number

6ES7 241-1CH30-1XB0

Dimensions

38 x 62 x 21

Weight

40 grams

Table A- 149 Transmitter and receiver
Technical data

CB 1241 RS485

Type

RS485 (2-wire half-duplex)

Common mode voltage range

-7 V to +12 V, 1 second, 3 VRMS continuous

Transmitter differential output voltage

2 V min. at RL = 100 Ω
1.5 V min. at RL = 54 Ω

Termination and bias

10K to +5 V on B, RS485 Pin 3
10K to GND on A, RS485 Pin 4

Optional termination

Short Pin TB to Pin T/RB, effective termination impedance is 127 Ω,
connects to RS485 Pin 3
Short Pin TA to Pin T/RA, effective termination impedance is 127 Ω,
connects to RS485 Pin 4

Receiver input impedance

5.4K Ω min. including termination

Receiver threshold/sensitivity

+/- 0.2 V min., 60 mV typical hysteresis

Isolation
RS485 signal to chassis ground
RS485 signal to CPU logic common

500 VAC, 1 minute

Cable length, shielded

1000 m max.

Baud rate

300 baud, 600 baud, 1.2 kbits, 2.4 kbits, 4.8 kbits, 9.6 kbits (default),
19.2 kbits, 38.4 kbits, 57.6 kbits, 76.8 kbits, 115.2 kbits,

Parity

No parity (default), even, odd, Mark (parity bit always set to 1),
Space (parity bit always set to 0)

Number of stop bits

1 (default), 2

Flow control

Not supported

Wait time

0 to 65535 ms

Table A- 150 Power supply
Technical data

CB 1241 RS485

Power loss (dissipation)

1.5 W

Current consumption (SM Bus), max.

50 mA

Current consumption (24 VDC) max.

80 mA

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Technical specifications
A.10 Communication interfaces

CB 1241 RS485 (6ES7 241-1CH30-1XB0)

① Connect "TA" and TB" as shown to terminate the network. (Terminate only the end
devices on the RS485 network.)
② Use shielded twisted pair cable and connect the cable shield to ground.
You terminate only the two ends of the RS485 network. The devices in between the two end
devices are not terminated or biased. See the section on "Biasing and terminating an RS485
network connector" (Page 426).

A.10.3.2

CM 1241 RS485 Specifications

Table A- 151 General specifications
Technical data

CM 1241 RS485

Order number

6ES7 241-1CH30-0XB0

Dimensions

30 x 100 x 75 mm

Weight

150 grams

Table A- 152 Transmitter and receiver
Technical data

CM 1241 RS485

Type

RS485 (2-wire half-duplex)

Common mode voltage range

-7 V to +12 V, 1 second, 3 VRMS continuous

Transmitter differential output voltage

2 V min. at RL = 100 Ω
1.5 V min. at RL = 54 Ω

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A.10 Communication interfaces

Technical data

CM 1241 RS485

Termination and bias

10K Ω to +5 V on B, PROFIBUS Pin 3
10K Ω to GND on A, PROFIBUS Pin 8

Receiver input impedance

5.4K Ω min. including termination

Receiver threshold/sensitivity

+/- 0.2 V min., 60 mV typical hysteresis

Isolation
RS485 signal to chassis ground
RS485 signal to CPU logic common

500 VAC, 1 minute

Cable length, shielded

1000 m max.

Baud rate

300 baud, 600 baud, 1.2 kbits, 2.4 kbits, 4.8 kbits, 9.6 kbits (default),
19.2 kbits, 38.4 kbits, 57.6 kbits, 76.8 kbits, 115.2 kbits,

Parity

No parity (default), even, odd, Mark (parity bit always set to 1),
Space (parity bit always set to 0)

Number of stop bits

1 (default), 2

Flow control

Not supported

Wait time

0 to 65535 ms

Table A- 153 Power supply
Technical data

CM 1241 RS485

Power loss (dissipation)

1.1 W

From +5 VDC

220 mA

Table A- 154 RS485 connector (female)
Pin

Description

Not connected

Signal B (RxD/TxD+): Input/Output

Request to send (TTL level): Output

3 TxD+
4 RTS
5 GND
1

Connector
(female)

Logic or communication ground

Description

6 PWR

+5V with 100 ohm series resistor: Output

Not connected

8 TXD-

Signal A (RxD/TxD-): Input/Output

Not connected

SHELL

Chassis ground

The RTS is a TTL level signal and can be used to control another half duplex device based on this signal. It is enabled
when you transmit and is disabled all other times. Unlike with the CM 1241 RS232, there is no user control of this signal
on the CM 1241 RS485. You cannot set it manually or cause it to be extended.

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Technical specifications
A.10 Communication interfaces

A.10.3.3

CM 1241 RS232 Specifications

Table A- 155 General specifications
Technical data

CM 1241 RS232

Order number

6ES7 241-1AH30-0XB0

Dimensions

30 x 100 x 75 mm

Weight

150 grams

Table A- 156 Transmitter and receiver
Technical data

CM 1241 RS232

Type

RS232 (full-duplex)

Transmitter output voltage

+/- 5 V min. at RL = 3K Ω

Transmit output voltage

+/- 15 VDC max.

Receiver input impedance

3 K Ω min.

Receiver threshold/sensitivity

0.8 V min. low, 2.4 max. high
0.5 V typical hysteresis

Receiver input voltage

+/- 30VDC max.

Isolation
RS 232 signal to chassis ground
RS 232 signal to CPU logic common

500 VAC, 1 minute

Cable length, shielded

10 m max.

Baud rate

300 baud, 600 baud, 1.2 kbits, 2.4 kbits, 4.8 kbits, 9.6 kbits (default),
19.2 kbits, 38.4 kbits, 57.6 kbits, 76.8 kbits, 115.2 kbits,

Parity

No parity (default), even, odd, Mark (parity bit always set to 1),
Space (parity bit always set to 0)

Number of stop bits

1 (default), 2

Flow control

Hardware, software

Wait time

0 to 65535 ms

Table A- 157 Power supply
Technical data

CM 1241 RS232

Power loss (dissipation)

1.1 W

From +5 VDC

220 mA

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Technical specifications
A.11 TeleService (TS Adapter and TS Adapter modular)
Table A- 158 RS232 connector (male)
Pin

Description

Connector
(male)

1 DCD

Data carrier detect: Input

2 RxD

Received data from DCE: Input

3 TxD

Transmitted data to DCE: Output

4 DTR

Data terminal ready: Output

5 GND

Logic ground

A.11

Description

6 DSR

Data set ready: Input

7 RTS

Request to send: Output

8 CTS

Clear to send: Input

9 RI

Ring indicator (not used)

SHELL

Chassis ground

TeleService (TS Adapter and TS Adapter modular)
The following manuals contain the technical specification for the TS Adapter IE Basic and
the TS Adapter modular:
● Industrial Software Engineering Tools
Modular TS Adapter
● Industrial Software Engineering Tools
TS Adapter IE Basic

A.12

SIMATIC memory cards
Order Number

Capacity

6ES7 954-8LF00-0AA0

24 MB

6ES7 954-8LB00-0AA0

2 MB

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Technical specifications
A.13 Input simulators

A.13

Input simulators

Table A- 159 General specifications
Technical data

8 Position Simulator

14 Position Simulator

Order number

6ES7 274-1XF30-0XA0

6ES7 274-1XH30-0XA0

Dimensions W x H x D (mm)

43 x 35 x 23

67 x 35 x 23

Weight

20 grams

30 grams

Points

Used with CPU

CPU 1211C, CPU 1212C

CPU 1214C

WARNING
These input simulators are not approved for use in Class I DIV 2 or Class I Zone 2
hazardous locations. The switches present a potential spark hazard/explosion hazard if
used in a Class I DIV 2 or Class I Zone 2 location.

8 Position Simulator (6ES7 274-1XF30-0XA0)

① 24 VDC sensor power out

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Technical specifications
A.14 I/O expansion cable

14 Position Simulator (6ES7 274-1XF30-0XA0)

① 24 VDC sensor
power out

A.14

I/O expansion cable
Technical Data
Order number

6ES7 290-6AA30-0XA0

Cable length

Weight

200 g

Refer to the installation section (Page 50) for information about installing and removing the
S7-1200 expansion cable.

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Technical specifications
A.15 Companion products

A.15

Companion products

A.15.1

PM 1207 power module
The PM 1207 is a power supply module for the SIMATIC S7-1200. It provides the following
features:
● Input 120/230 VAC, output 24 VDC/2.5A
● Order number 6ESP 332-1SH71
For more information about this product and for the product documentation, refer to the
customer support web site (http://www.siemens.com/automation/support-request).

A.15.2

CSM 1277 compact switch module
The CSM1277 is an Industrial Ethernet compact switch module. It can be used to multiply
the Ethernet interface of the S7-1200 to allow simultaneous communication with operator
panels, programming devices, or other controllers. It provides the following features:
● 4 x RJ45 sockets for connecting to Industrial Ethernet
● 3 pole plug in terminal strip for connection of the external 24 VDC supply on top
● LEDs for diagnostics and status display of Industrial Ethernet ports
● Order number 6GK7 277-1AA00-0AA0
For more information about this product and for the product documentation, refer to the
customer support web site (http://www.siemens.com/automation/support-request).

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Calculating a power budget

The CPU has an internal power supply that provides power for the CPU itself, for any
expansion modules, and for other 24 VDC user power requirements.
There are four types of expansion modules:
● Signal modules (SM) are installed on the right-side of the CPU. Each CPU allows a
maximum number of signal modules possible without regard to the power budget.
– CPU 1214 allows 8 signal modules
– CPU 1212 allows 2 signal modules
– CPU 1211 allows no signal modules
● Communication modules (CM) are installed on the left-side of the CPU. A maximum of 3
communication modules is allowed for any CPU without regard to the power budget.
● Signal boards (SB) are installed on top of the CPU. A maximum of 1 signal board or
communication board is allowed for any CPU.
● Communication boards (CB) are installed on top of the CPU. A maximum of 1 signal
board or communication board is allowed for any CPU.
Use the following information as a guide for determining how much power (or current) the
CPU can provide for your configuration.
Each CPU supplies both 5 VDC and 24 VDC power:
● The CPU provides 5 VDC power for the expansion modules when an expansion module
is connected. If the 5 VDC power requirements for expansion modules exceed the power
budget of the CPU, you must remove expansion modules until the requirement is within
the power budget.
● Each CPU has a 24 VDC sensor supply that can supply 24 VDC for local input points or
for relay coils on the expansion modules. If the power requirement for 24 VDC exceeds
the power budget of the CPU, you can add an external 24 VDC power supply to provide
24 VDC to the expansion modules. You must manually connect the 24 VDC supply to the
input points or relay coils.
WARNING
Connecting an external 24 VDC power supply in parallel with the DC sensor supply can
result in a conflict between the two supplies as each seeks to establish its own preferred
output voltage level.
The result of this conflict can be shortened lifetime or immediate failure of one or both
power supplies, with consequent unpredictable operation of the PLC system.
Unpredictable operation could result in death, severe personal injury and/or property
damage.
The DC sensor supply on the CPU and any external power supply should provide power
to different points. A single connection of the commons is allowed.

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Calculating a power budget

Some of the 24V power input ports in the PLC system are interconnected, with a logic
common circuit connecting multiple M terminals. The CPU 24V power supply input, the SM
relay coil power input, and a non-isolated analog power supply input are examples of circuits
that are interconnected when designated as not isolated in the data sheets. All non-isolated
M terminals must connect to the same external reference potential.
WARNING
Connecting non-isolated M terminals to different reference potentials will cause unintended
current flows that may cause damage or unpredictable operation in the PLC and connected
equipment.
Such damage or unpredictable operation could result in death, severe personal injury
and/or property damage.
Always be sure that all non-isolated M terminals in a PLC system are connected to the
same reference potential.
Information about the power budgets of the CPUs and the power requirements of the signal
modules is provided in the technical specifications (Page 561).
Note
Exceeding the power budget of the CPU may result in not being able to connect the
maximum number of modules allowed for your CPU.

Sample power budget
The following example shows a sample calculation of the power requirements for a
configuration that includes one CPU 1214C AC/DC/Relay, one SB 1223 2 x 24 VDC Input/ 2
x 24 VDC Output, one CM 1241, three SM 1223 8 DC In/8 Relay Out, and one SM 1221 8
DC In. This example has a total of 48 inputs and 36 outputs.
Note
The CPU has already allocated the power required to drive the internal relay coils. You do
not need to include the internal relay coil power requirements in a power budget calculation.
The CPU in this example provides sufficient 5 VDC current for the SMs, but does not provide
enough 24 VDC current from the sensor supply for all of the inputs and expansion relay
coils. The I/O requires 456 mA and the CPU provides only 400 mA. This installation requires
an additional source of at least 56 mA at 24 VDC power to operate all the included 24 VDC
inputs and outputs.

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Calculating a power budget

Table B- 1

Sample power budget

CPU power budget

5 VDC

CPU 1214C AC/DC/Relay

1600 mA

24 VDC
400 mA

Minus
System requirements

5 VDC

24 VDC

CPU 1214C, 14 inputs

14 * 4 mA = 56 mA

1 SB 1223 2 x 24 VDC Input/ 2 x 24
VDC Output

50 mA

2 * 4 mA = 8 mA

1 CM 1241 RS 485, 5 V power

220 mA

3 SM 1223, 5 V power

3 * 145 mA = 435 mA

1 SM 1221, 5 V power

1 * 105 mA = 105 mA

3 SM 1223, 8 inputs each

3 * 8 * 4 mA = 96 mA

3 SM 1223, 8 relay coils each

3 * 8 * 11 mA = 264 mA

1 SM 1221, 8 inputs each

8 * 4 mA = 32 mA

Total requirements

810 mA

456 mA

Equals
Current balance

5 VDC

24 VDC

Current balance total

790 mA

(56 mA)

Form for calculating your power budget
Use the following table to determine how much power (or current) the S7-1200 CPU can
provide for your configuration. Refer to the technical specifications (Page 561) for the power
budgets of your CPU model and the power requirements of your signal modules.
Table B- 2

Calculations for a power budget

CPU power budget

5 VDC

24 VDC

Minus
System requirements

5 VDC

24 VDC

Total requirements

Equals
Current balance

5 VDC

24 VDC

Current balance total

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Order numbers
C.1
Table C- 1

CPU modules
S7-1200 CPUs

CPU models

Order Number

CPU 1211C

CPU 1212C

CPU 1214C

C.2
Table C- 2

CPU 1211C DC/DC/DC

6ES7 211-1AD30-0XB0

CPU 1211C AC/DC/Relay

6ES7 211-1BD30-0XB0

CPU 1211C DC/DC/Relay

6ES7 211-1HD30-0XB0

CPU 1212C DC/DC/DC

6ES7 212-1AD30-0XB0

CPU 1212C AC/DC/Relay

6ES7 212-1BD30-0XB0

CPU 1212C DC/DC/Relay

6ES7 212-1HD30-0XB0

CPU 1214C DC/DC/DC

6ES7 214-1AE30-0XB0

CPU 1214C AC/DC/Relay

6ES7 214-1BE30-0XB0

CPU 1214C DC/DC/Relay

6ES7 214-1HE30-0XB0

Signal modules (SMs) and signal boards (SBs)
Signal boards (SBs)

Signal boards
Digital input

Order Number
SB 1221 200 KHz 4 x 24 VDC Input (Source),

6ES7 221-3BD30-0XB0

SB 1221 200 KHz 4 x 5 VDC Input (Source)

6ES7 221-3AD30-0XB0

Digital output

SB 1222 200 KHz 4 x 24 VDC Output (Sink/Source)

6ES7 222-1BD30-0XB0

SB 1222 200 KHz 4 x 5 VDC Output (Sink/Source)

6ES7 222-1AD30-0XB0

Digital input /
output

SB 1223 2 x 24 VDC Input (Sink) / 2 x 24 VDC Output (Source)

6ES7 223-0BD30-0XB0

SB 1223 200 KHz 2 x 24 VDC Input (Source) / 2 x 24 VDC Output
(Sink/Source)

6ES7 223-3BD30-0XB0

SB 1223 200 KHz 2 x 5 VDC Input (Source) / 2 x 5 VDC Output
(Sink/Source)

6ES7 223-3AD30-0XB0

Analog

SB 1232 1 Analog Output

6ES7 232-4HA30-0XB0

SB 1231 1 Analog Input

6ES7 231-4HA30-0XB0

SB 1231 1 Analog Input Thermocouple

6ES7 231-5QA30-0XB0

SB 1231 1 Analog Input RTD

6ES7 231-5PA30-0XB0

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Order numbers
C.3 Communication
Table C- 3

Signal modules (SMs)

Signal modules
Digital input
Digital output

Order Number
SM 1221 8 x 24 VDC Input (Sink/Source)

6ES7 221-1BF30-0XB0

SM 1221 16 x 24 VDC Input (Sink/Source)

6ES7 221-1BH30-0XB0

SM 1222 8 x 24 VDC Output (Source)

6ES7 222-1BF30-0XB0

SM 1222 16 x 24 VDC Output (Source)

6ES7 222-1BH30-0XB0

SM 1222 8 x Relay Output

6ES7 222-1HF30-0XB0

SM 1222 16 x Relay Output

6ES7 222-1HH30-0XB0

SM 1223 8 x 24 VDC Input (Sink/Source) / 8 x 24 VDC Output
(Source)

6ES7 223-1BH30-0XB0

SM 1223 16 x 24 VDC Input (Sink/Source) / 16 x 24 VDC Output
(Source)

6ES7 223-1BL30-0XB0

SM 1223 8 x 24 VDC Input (Sink/Source) / 8 x Relay Output

6ES7 223-1PH30-0XB0

SM 1223 16 x 24 VDC Input (Sink/Source) / 16 x Relay Output

6ES7 223-1PL30-0XB0

SM 1223 8 x 120/230 VAC Input (Sink/Source) / 8 x Relay Outputs

6ES7 223-1QH30-0XB0

Analog input

SM 1231 4 x Analog Input

6ES7 231-4HD30-0XB0

SM 1231 8 x Analog Input

6ES7 231-4HF30-0XB0

Analog output

SM 1232 2 x Analog Output

6ES7 232-4HB30-0XB0

SM 1232 4 x Analog Output

6ES7 232-4HD30-0XB0

Analog input /
output

SM 1234 4 x Analog Input / 2 x Analog Output

6ES7 234-4HE30-0XB0

RTD and
thermocouple

SM 1231 TC 4 x 16 bit

6ES7 231-5QD30-0XB0

Digital input /
output

C.3
Table C- 4

SM 1231 TC 8 x 16 bit

6ES7 231-5QF30-0XB0

SM 1231 RTD 4 x 16 bit

6ES7 231-5PD30-0XB0

SM 1231 RTD 8 x 16 bit

6ES7 231-5PF30-0XB0

Communication
Communication module (CM)

Communication module (CM)

Order Number

RS232 and RS485 CM 1241 RS232

RS232

CM 1241 RS485

RS485

6ES7 241-1CH30-0XB0

CM 1243-5

PROFIBUS Master

6GK7 243-5DX30-0XE0

CM 1242-5

PROFIBUS Slave

6GK7 242-5DX30-0XE0

PROFIBUS

Table C- 5

Communication board (CB)

Communication board (CB)
RS485

6ES7 241-1AH30-0XB0

CB 1241 RS485

Order Number
RS485

6ES7 241-1CH30-1XB0

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Order numbers
C.4 Other modules
Table C- 6

Communication Processor (CP)

Communication processor (CP)

Order Number

CP 1242-7

6GK7 242-7KX30-0XE0

Table C- 7

GPRS

TeleService

TS Adapter

Order Number

TS Adapter IE Basic

6ES7 972-0EB00-0XA0

TS Module GSM

6GK7 972-0MG00-0XA0

TS Module RS232

6ES7 792-0MS00-0XA0

TS Module Modem

6ES7 972-0MM00-0XA0

TS Module ISDN

6ES7 972-0MD00-0XA0

Table C- 8

Accessories

Accessory

Order Number

Antenna

Table C- 9

ANT794-4MR

GSM/GPRS antenna

6NH9 860-1AA00

ANT794-3M

Flat antenna

6NH9 870-1AA00

Connectors

Type of Connector

Order Number

RS485

35-degree cable output, screw-terminal connection

6ES7 972-0BA42-0XA0

35-degree cable output, FastConnect connection

6ES7 972-0BA60-0XA0

C.4
Table C- 10

Other modules
Companion products

Item

Order Number

Power supply module

PM 1207 power supply

6EP1 332-1SH71

Ethernet switch

CSM 1277 Ethernet switch - 4 ports

6GK7 277-1AA10-0AA0

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Order numbers
C.5 Memory cards

C.5
Table C- 11

Memory cards
Memory cards

SIMATIC memory cards

Order Number

SIMATIC MC 2 MB

6ES7 954-8LB00-0AA0

SIMATIC MC 24 MB

6ES7 954-8LF00-0AA0

C.6
Table C- 12

Basic HMI devices
HMI devices

HMI Basic Panels

Order Number

KTP400 Basic (Mono, PN)

6AV6 647-0AA11-3AX0

KTP600 Basic (Mono, PN)

6AV6 647-0AB11-3AX0

KTP600 Basic (Color, PN)

6AV6 647-0AD11-3AX0

KTP1000 Basic (Color, PN)

6AV6 647-0AF11-3AX0

TP1500 Basic (Color, PN)

6AV6 647-0AG11-3AX0

C.7
Table C- 13

Spare parts and other hardware
Expansion cables, simulators and connector blocks

Item

Order Number

I/O expansion cable

I/O Expansion cable, 2 m

6ES7 290-6AA30-0XA0

I/O simulator

Simulator (1214C/1211C - 8 position)

6ES7 274-1XF30-0XA0

Simulator (1214C - 14 position)

6ES7 274-1XH30-0XA0

CPU 1211/1212

6ES7 291-1AA30-0XA0

CPU 1214

6ES7 291-1AB30-0XA0

Signal module, 45 mm

6ES7 291-1BA30-0XA0

Signal module, 70 mm

6ES7 291-1BB30-0XA0

Communication module

6ES7 291-1CC30-0XA0

Tin

7 terminal, 4/pk

6ES7 292-1AG30-0XA0

8 terminal, 4/pk

6ES7 292-1AH30-0XA0

11 terminal, 4/pk

6ES7 292-1AL30-0XA0

12 terminal, 4/pk

6ES7 292-1AM30-0XA0

14 terminal, 4/pk

6ES7 292-1AP30-0XA0

Spare door kit

Connector block

Gold

20 terminal, 4/pk

6ES7 292-1AV30-0XA0

3 terminal, 4/pk

6ES7 292-1BC30-0XA0

6 terminal, 4/pk

6ES7 292-1BF30-0XA0

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Order numbers
C.8 Programming software

Item

Order Number

Strain relief

C.8
Table C- 14

7 terminal, 4/pk

6ES7 292-1BG30-0XA0

11 terminal, 4/pk

6ES7 292-1BL30-0XA0

Strain Relief, CPU1200, Ethernet (4/pk)

6ES7 290-3AA30-0XA0

Programming software
Programming software

SIMATIC software

Order Number

Programming software

STEP 7 Basic V11
STEP 7 Professional V11

6ES7 822-1AA01-0YA5

Visualization software

WinCC Basic V11

6AV2100-0AA01-0AA0

WinCC Comfort V11

6AV2101-0AA01-0AA5

WinCC Advanced V11

6AV2102-0AA01-0AA5

WinCC Professional 512 PowerTags V11

6AV2103-0DA01-0AA5

C.9
Table C- 15

6ES7 822-0AA01-0YA0

WinCC Professional 4096 PowerTags V11

6AV2103-0HA01-0AA5

WinCC Professional max. PowerTags V11

6AV2103-0XA01-0AA5

Documentation
S7-1200 documentation

Printed documentation

Language

Order Number

S7-1200 Programmable Controller System Manual

German

6ES7 298-8FA30-8AH0

English

6ES7 298-8FA30-8BH0

S7-1200 Easy Book

French

6ES7 298-8FA30-8CH0

Spanish

6ES7 298-8FA30-8DH0

Italian

6ES7 298-8FA30-8EH0

Chinese

6ES7 298-8FA30-8KH0

German

6ES7 298-8FA30-8AQ0

English

6ES7 298-8FA30-8BQ0

French

6ES7 298-8FA30-8CQ0

Spanish

6ES7 298-8FA30-8DQ0

Italian

6ES7 298-8FA30-8EQ0

Chinese

6ES7 298-8FA30-8KQ0

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Order numbers
C.9 Documentation

S7-1200 Programmable controller

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Index

A
ABS (absolute value), 173
AC
grounding, 57
inductive loads, 59
isolation guidelines, 57
wiring guidelines, 56, 57
Access protection
CPU, 138
Accessing
data logs from PC, 503
user-defined Web pages, 526
ACOS (arc cosine or inverse cosine), 176
Active/passive communication
configuring the partners, 110
connections and port IDs, 362
parameters, 113
Active/Passive connection, 360
Ad hoc mode
ISO on TCP, 365
TCP, 365
ADD (add), 170
Add new device
CPU, 104
detect existing hardware, 105
unspecific CPU, 105
Adding inputs or outputs to LAD or FBD
instructions, 32
Addressing
Boolean or bit values, 79
individual inputs (I) or outputs (Q), 79
memory areas, 79
process image, 79
Air flow, 39
Alarm
peripheral access, 401
Alarm interrupt, 255
Aliases in user-defined Web pages, 516
Analog I/O
configuration, 109
conversion to engineering units, 31, 83, 187
input representation (voltage), 572, 580, 588, 607,
630
output representation (current), 607, 630

output representation (voltage), 608, 631
status indicators, 546
step response times (CPU), 572, 580, 588
step response times (SB), 629
step response times (SM), 606
Analog signal (SM)
SM 1232 AQ 4 x 14bit, 602
Analog signal board (SB)
SB 1231 AI 1 x 12 bit, 625
SB 1231 AI 1 x 16 bit RTD, 635
SB 1231 AI 1 x 16 bit Thermocouple, 631
SB 1232 AQ 1x12 bit, 628
Analog signal module (SM)
SM 1231 AI 4 x RTD x 16 bit, 612
SM 1231 AI 8 x 13 bit, 600
SM 1231 AI 8 x 16 bit TC, 608
SM 1231 AI 8 x RTD x 16 bit, 612
SM 1231 AI4 x 16 bit TC, 608
SM 1232 AQ 2 x 14bit, 602
SM 1234 AI 4 x 13 bit / AQ 2 x 14 bit, 603
AND, 199
Approvals
ATEX approval, 562
CE approval, 561
C-Tick approval, 563
cULus approval, 562
FM approval, 562
maritime approval, 563
ASIN (arc sine or inverse sine), 176
Assigning enum types, user-defined Web pages, 517
ATEX approval, 562
ATH (ASCII to hexadecimal), 224
ATTACH, 247
AWP commands, 510
combining definitions, 520
defining an enum type, 516
generating fragments, 519
importing fragments, 520
reading special variables, 513
referencing an enum type, 517
using an alias, 516
writing special variables, 514
writing variables, 512
AWP_Enum_Def, 516
AWP_Enum_Ref, 517
AWP_Import_Fragment, 520
AWP_In_Variable, 512, 514
AWP_Out_Variable, 513

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Index

CAN_DINT (cancel time delay interrupt), 253
Capturing the status of a code block, 35
Capturing values from an online DB, 554
B
CB 1241 RS485 specifications, 647
CE approval, 561
Basic panels (HMI), 25
CEIL (ceiling), 185
Baud rate, 445
Certificate Import Wizard, 506
Binding to a CPU or memory card, 140
Changing settings for STEP 7, 33
Bit logic, 147
Char (character data type), 88
Block
Character position
consistency check, 146
message length, 453
Block move (MOVE_BLK), 178
Character sequence
Blocks
message end, 452
block calls, 61
message start, 449
copying blocks from an online CPU, 142
Clearance
counters (quantity and memory requirements), 19,
airflow and cooling, 39
568, 576, 584
Clock
data block (DB), 61
memory byte, 77
download, 142
RD_LOC_T (read local time), 209
events, 67
RD_SYS_T (read system time), 209
function (FC), 61, 132
time-of-day clock, 75
function block (FB), 61, 132
WR_SYS_T (write system time), 209
initial value of an FB, 132
CM 1241
instance data block (DB), 132
RS232 specifications, 651
interrupts, 19, 67, 568, 576, 584
RS485 specifications, 648
linear and structured programs, 128
Code block
monitoring, 19, 568, 576, 584
binding to a CPU or memory card, 140
nesting depth, 19, 61, 568, 576, 584
block calls, 61
number of code blocks, 19, 568, 576, 584
calling code blocks within the user program, 129
number of OBs, 19, 67, 568, 576, 584
capturing the status of a code block, 35
organization blocks (OBs), 19, 61, 66, 67, 568, 576,
copy protection, 140
584
counters (quantity and memory requirements), 19,
password protection, 139
568, 576, 584
single instance or multi-instance DB, 132
DB (data block), 61, 133
size of the user program, 19, 61, 568, 576, 584
FB (function block), 61, 132
start-up OBs, 67
FC (function), 61, 132
timers (quantity and memory requirements), 19,
initial value of an FB, 132
568, 576, 584
instance data block (DB), 132
types of code blocks, 61
interrupts, 19, 568, 576, 584
valid FC, FB, and DB numbers, 61
know-how protection, 139
Boolean or bit values, 79
linear and structured programs, 128
Break, 447, 448
monitoring, 19, 568, 576, 584
BUFFER parameter, SEND_PTP, 439
nesting depth, 19, 568, 576, 584
Bus connector, 22
number of code blocks, 19, 568, 576, 584
number of OBs, 19, 568, 576, 584
organization block (OB), 130
C
organization blocks (OBs), 19, 568, 576, 584
CALCULATE, 30, 169
restoring the status of a code block, 35
scaling analogs, 31
size of the user program, 19, 568, 576, 584
Calendar, 207
timers (quantity and memory requirements), 19,
Call structure, 146
568, 576, 584
Calling code blocks within the user program, 129
types of code blocks, 61
AWP_Start_Fragment, 519

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valid FC, FB, and DB numbers, 61
Code blocks, 129
Cold junction compensation
Thermocouple, 611, 633
Columns and headers in task cards, 33
Communication
active/passive, 110, 113
communication load, 73
configuration, 110, 113
connections and port IDs, 362
cycle time, 73
flow control, 445
hardware connection, 390
IP address, 119
MAC address, 119
network, 390
network connection, 109
number of connections (PROFINET), 360
parameters, 113, 500
polling architecture, 455
PROFIBUS address, 408
PROFINET and PROFIBUS, 359
send and receive parameters, 447
statistics, 500
TCON_Param, 113
time synchronization property (PROFINET), 124
Communication board (CB)
add modules, 106
CB 1241 RS485, 647
comparison chart, 20
configuration of parameters, 108
device configuration, 103
installation, 45
LED indicators, 425, 545
overview, 22
programming, 454
removal, 45
RS485, 425
Communication interfaces
add modules, 106
CB 1241 RS485, 647
CM 1241 RS232, 651
CM 1241 RS485, 648
comparison chart of the modules, 20
configuration, 444
device configuration, 103
LED indicators, 545
programming, 454
RS232 and RS485, 425
Communication module (CM)
add CM 1243-5 (DP master) module, 407
add modules, 106

CM 1241 RS232 specifications, 651
CM 1241 RS485, 648
comparison chart, 20
configuration for PtP example program, 456
configuration of parameters, 108
data reception, 440
device configuration, 103
installation, 48
LED indicators, 425, 545
overview, 22
power requirements, 655
programming, 454
removal, 48
RS232 and RS485, 425
Communication processor (CP)
add modules, 106
comparison chart, 20
configuration of parameters, 108
device configuration, 103
overview, 22
Communication standard Web page, 500
Compare, 167
Comparing and synchronizing online/offline CPUs, 551
Comparing code blocks, 551
Comparison chart
CPU models, 18
HMI devices, 25
modules, 20
Computer requirements, 27
CONCAT (concatenate), 227
Configuration
add modules, 106
communication interfaces, 444
communication load, 73
CPU parameters, 107
cycle time, 72
discover, 105
download, 142
Ethernet port, 119
HSC (high-speed counter), 295
IP address, 119
MAC address, 119
modules, 108
network connection, 109
PLC to PLC communication, 394
ports, 444
PROFIBUS, 408
PROFIBUS address, 408
PROFIBUS port, 408
PROFINET, 119
receive message, 448
startup parameters, 97

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667

Index

time synchronization property (PROFINET), 124
user-defined Web pages, 522
user-defined Web pages (multiple languages), 540
Connections
configuration, 113
Ethernet protocols, 415
number of connections (PROFINET), 360
partners, 110
port IDs, 362
S7 connection, 415
types of communication, 359
types, multi-node connections, 415
Connector
installation and removal, 49
Consistency check, 146
Constraints
user-defined Web pages, 526
Web server, 504
Contact information, 3
Control DB for user-defined Web pages
global commands, 541
parameter to WWW instruction, 524
request commands and states, 541
CONV (convert), 183
Cookie restrictions, standard Web pages, 506
Cookie, siemens_automation_language, 538
Cooling, 39
Copy protection
binding to a CPU or memory card, 140
Copying blocks from an online CPU, 142
COS (cosine), 176
Counters
HSC (high-speed counter), 287
HSC configuration, 295
HSC operation, 289
quantity, 19, 568, 576, 584
size, 19, 568, 576, 584
CPU
1211C specifications, 566
1211C wiring diagrams, 574
1212C specifications, 574
1212C wiring diagrams, 582
1214C specifications, 582
1214C wiring diagrams, 590
access protection, 138
add modules, 106
add new device, 104
analog input representation (voltage), 572, 580,
588, 607, 630
assigning an IP address to an online CPU, 117
capturing the status of a code block, 35
capturing values of a DB, 554

communication board (CB), 22
communication load, 73
comparing and synchronizing blocks, 551
comparison chart, 18
configuring communication to HMI, 392
configuring multiple, 394
configuring parameters, 107
configuring pulse channels, 264
configuring the modules, 108
copying blocks from an online CPU, 142
creating a program card, 100
creating a transfer card, 98
cycle time configuration, 73
cycle time monitoring, 72
device configuration, 103
displaying the MAC and IP addresses, 122
download, 142
download to device, 122
empty transfer card, 102
enable outputs in STOP mode, 557
Ethernet port, 119
expansion cable, 50
force, 558, 559
going online, 547
grounding, 57
HMI devices, 25
HSC configuration, 295
inductive loads, 59
inserting the memory card:inserting, 96
installation, 43, 44
IP address, 119
isolation guidelines, 57
know-how protection, 139
lamp loads, 58
LED indicators, 545
lost password, 102
MAC address, 119, 122
memory card, 95, 651
monitoring, 553
network connection, 109
number of communication connections, 360
online, 549, 553
operating modes, 63
operating panel (online CPU), 550
operator panel, 35
overview, 17
password protection, 138
power budget, 40
power requirements, 655
processing the OBs, 130
PROFIBUS, 408
PROFIBUS address, 408

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Index

PROFIBUS port, 408
PROFINET, 119
PROFINET IO, 398
program card, 95, 100
program execution, 61
pulse outputs, 263
RD_LOC_T (read local time), 209
RD_SYS_T (read system time), 209
recover from a lost password, 102
resetting the start values of a DB, 554
restoring the status of a code block, 35
RUN and STOP mode, 550
run time meter, 211
RUN/STOP buttons, 35
Security levels, 138
signal board (SB), 22
startup parameters, 97
startup processing, 65
step response times, 572, 580, 588
terminal block connector, 49
thermal zone, 39, 42
time synchronization property, 124
transfer card, 95, 98
types of communication, 359
unspecific CPU, 105
watch table, 555
wiring guidelines, 56, 57
WR_SYS_T (write system time), 209
CPU communication, 361
CPU Identification standard Web page, 497
CPU properties, user-defined Web pages, 522
CPU properties, user-defined Web pages (multiple
languages), 540
Creating a network connection, 109
Creating user-defined Web page DBs, 524
Creating user-defined Web pages, 509
Cross-references, 145
Introduction, 145
Uses, 145
CTD (count down), 161
C-Tick approval, 563
CTRL_PWM, 261
CTS, 445
CTU (count up), 161
CTUD (count up and down), 161
cULus approval, 562
Customer support, 3
Cycle time
configuration, 73
monitoring, 550
overview, 72

D
Data block
capturing values, 554
CONF_DATA, 386
global data block, 78, 133
instance data block, 78
organization block (OB), 130
overview, 61, 133
resetting the start values, 554
single FB with multiple instance DBs, 133
valid DB numbers, 61
data block control, 265
Data blocks for user-defined Web pages
importing fragments, 520
Data handling block (DHB), 133
Data log
Data log overview, 269
data record structure, 269
DataLogClose (close Data log), 274
DataLogCreate (create Data log), 270
DataLogNewFile (create Data log based on existing
Data log), 277
DataLogOpen (open Data log), 273
DataLogWite (write Data log), 275
example program, 282
limits to Data log size, 280
viewing Data logs, 279
Data Logs standard Web page, 503
Data transmission, initiating, 437
Data types, 84
Any (pointer), 93
arrays, 90
Bool, Byte, Word, and DWord, 85
Char (character) and string, 88
PLC data type editor, 91
Pointer (pointer), 92
pointer data type overview, 91
Real, LReal (floating-point real), 86
Struc, 91
Time, Date, TOD (time of day), DTL (date and time
long), 87
USInt, SInt, UInt, Int, UDInt, Dint (integer), 86
Variant (pointer), 94
Date
Date data type, 87
DTL (date and time long data type), 88
SET_TIMEZONE (set time zone), 212
T_ADD (add time), 208
T_COMBINE (combine times), 209
T_CONV (convert time), 207
T_DIFF (time difference), 208
T_SUB (subtract time), 208

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Index

DB (data block), 61, 133
capturing values, 554
resetting the start values, 554
valid DB numbers, 61
DC
grounding, 57
inductive loads, 59
isolation guidelines, 57
wiring guidelines, 56, 57
DEC (decrement), 173
DECO (decode), 200
Defining enum types, user-defined Web pages, 516
DELETE (delete substring), 230
Designing a PLC system, 127, 128
DETACH, 247
Device
PROFINET IO, 398
Device configuration, 103, 391
add modules, 106
add new device, 104
configuring the CPU, 107
configuring the modules, 108
discover, 105
download, 142
Ethernet port, 119
network connection, 109
PROFIBUS, 408
PROFIBUS port, 408
PROFINET, 119
time synchronization property (PROFINET), 124
unplugged modules, 38
Device names
PROFINET IO, 399
DeviceStates, 257
Diagnostic standard Web page, 497
Diagnostics
cycle time, 550
DeviceStates, 257
diagnostics buffer, 551
GET_DIAG, 259
interrupt OB, 401
LED indicators, 545
LED instruction, 256
memory usage, 550
ModuleStates, 258
status, 401
status indicator, 77
watch table, 555
Diagnostics buffer, 75, 551
Digital I/O
configuration, 108
status indicators, 546

Digital signal board (SB) specifications
SB 1221 DI 4, 200 kHz, 617
SB 1222 DQ 4, 200 kHz, 619
SB 1223 DI 2 / DQ 2, 623
SB 1223 DI 2 / DQ 2, 200 kHz, 621
Digital signal module (SM)
SM 1221, 590
SM 1222, 593
SM 1223, 596
DIN rail, 43
Directories, languages for user-defined Web
pages, 538
DIS_AIRT (disable alarm interrupt), 255
Discover to upload an online CPU, 105
Displaying the MAC and IP addresses, 122
DIV (divide), 170
Documentation, 4
Downloading
displaying the MAC and IP addresses, 122
project, 142
Siemens security certificate to PC, 496, 506
user program, 142
user-defined Web page DBs, 525
DPNRM_DG, 244
DPRD_DAT, 242
DPWR_DAT, 242
Drag and drop between editors, 34
DTL data type
system clock instructions, 209

E
Electromagnetic compatibility (EMC), 563
EN and ENO (power flow), 137
EN_AIRT (enable alarm interrupt), 255
ENCO (encode), 200
End conditions, 450
End message character, 452
Enum types in user-defined Web pages, 516, 517
Environmental
industrial environments, 563
operating conditions, 564
transport and storage conditions, 564
Error codes
common errors for extended instructions, 267
RALRM, 239
RDREC, 239
WRREC, 239
Errors
diagnostic errors, 71
time errors, 70
Ethernet
S7-1200 Programmable controller

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Index

ad hoc mode, 365
connections and port IDs, 362
DPNRM_DG, 244
DPRD_DAT, 242
DPWR_DAT, 242
GET, 412
IP address, 119
MAC address, 119
network connection, 109
number of communication connections, 360
overview, 364
PUT, 412
RALRM, 237
RDREC, 234
T_CONFIG, 384
TCON, 372
TDISCON, 372
TRCV, 372
TRCV_C, 366
TSEND, 372
TSEND_C, 366
TURCV, 380
TUSEND, 380
types of communication, 359
WRREC, 234
Ethernet protocols, 415
multi-node connections, 415
Event execution, 67
Example
Modbus master, 488
Modbus slave, 489
PtP communication, 456
PtP communication, configuration, 456
PtP communication, running, 459
PtP communication, STEP 7 programming, 458
PtP communication, terminal emulator, 459
user-defined Web pages, 527
EXP (natural exponential), 176
Expandable instructions, 32
Expanding the capabilities of the S7-1200, 20
Expansion cable
installation, 50
removal, 50
EXPT (general exponential), 176

F
FAQs, 4
Favorites toolbar, 29
FB (function block)
overview, 61
valid FB numbers, 61

FBD (function block diagram), 137
FC (function), 61, 132
valid FC numbers, 61
FieldRead, 180
FieldWrite, 180
FILL_BLK, 181
FIND (find substring), 233
First scan indicator, 77
Floating-point math, 176
FLOOR, 185
Flow control, 445
configuration, 445
FM approval, 562
Folders, languages for user-defined Web pages, 538
Force, 558, 559
I memory, 558, 559
inputs and outputs, 559
memory card does not contain force values, 95
peripheral inputs, 558, 559
scan cycle, 559
watch table, 555
Force table
addressing peripheral inputs, 558
force, 558
force operation, 559
FRAC (fraction), 176
Fragment DBs (user-defined Web pages)
generating, 524
Fragments (user-defined Web pages)
creating from AWP command, 519
importing with AWP command, 520
Freeport protocol, 427
Frequency, clock bits, 77
Function (FC)
calling code blocks within the user program, 129
capturing the status of a code block, 35
know-how protection, 139
linear and structured programs, 128
overview, 61, 132
restoring the status of a code block, 35
valid FC numbers, 61
Function block (FB)
calling code blocks within the user program, 129
capturing the status of a code block, 35
initial value, 132
instance data block, 132
know-how protection, 139
linear and structured programs, 128
output parameters, 132
overview, 61, 132
restoring the status of a code block, 35
single FB with multiple instance DBs, 133

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Index

valid FB numbers, 61

G
General technical specifications, 561
Generating user-defined Web page DBs, 524
GET, 259
configuring the connection, 111
Get LED status, 256
GET_DIAG, 259
GetError, 195
GetErrorID, 197
Global data block, 78, 133
Global library
USS protocol overview, 460
Guidelines
CPU installation, 44
grounding, 57
inductive loads, 59
installation, 39
installation procedures, 43
isolation, 57
lamp loads, 58
wiring guidelines, 56, 57

H
Hardware configuration, 103
add modules, 106
add new device, 104
configuring the CPU, 107
configuring the modules, 108
discover, 105
download, 142
Ethernet port, 119
network connection, 109
PROFIBUS, 408
PROFIBUS port, 408
PROFINET, 119
Hardware flow control, 445
High-speed counter
configuration, 295
HSC, 287
operation, 289
High-speed counter (HSC)
cannot be forced, 559
HMI devices
configuring PROFINET communication, 392
network connection, 109
overview, 25
Hotline, 3

HSC (high-speed counter)
configuration, 295
operation, 287, 289
HTA (hexadecimal to ASCII), 225
HTML listing, user-defined Web page example, 532
HTML pages, user-defined, 508
accessing S7-1200 data, 510
developing, 509
language locations, 540
page locations, 522
refreshing, 509

I
I memory
force, 558
force operation, 559
force table, 558
HSC (high-speed counter), 289
monitor, 553
monitor LAD, 554
peripheral input addresses (force table), 558
watch table, 553
I/O
access errors, PROFINET, 402
addressing, 83
analog input representation (voltage), 572, 580,
588, 607, 630
analog output representation (current), 607, 630
analog output representation (voltage), 608, 631
analog status indicators, 546
digital status indicators, 546
force, 558
force operation, 559
inductive loads, 59
monitoring status in LAD, 554
monitoring with a watch table, 555
step response times (CPU), 572, 580, 588
step response times (SB), 629
step response times of the signal module (SM), 606
Identification standard Web page, 497
Idle line, 447, 449
Importing Siemens security certificate, 506
IN_RANGE (within a range), 168
INC (increment), 173
Inductive loads, 59
Information resources, 4
Initial values
capturing and resetting the start values of a DB, 554
Input simulators, 653
Inputs and outputs
monitoring, 553
S7-1200 Programmable controller

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Index

INSERT (insert substring), 231
Inserting a device
unspecific CPU, 105
Inserting instructions
drag and drop, 29
drag and drop between editors, 34
favorites, 29
Inserting the memory card into CPU, 96
Installation
air flow, 39
clearance, 39
communication board (CB), 45
communication module (CM), 48
cooling, 39
CPU, 44
expansion cable, 50
grounding, 57
guidelines, 39
inductive loads, 59
isolation guidelines, 57
lamp loads, 58
mounting dimensions, 42
overview, 39, 43
power budget, 40
signal board (SB), 45
signal module (SM), 22, 46
terminal block connector, 49
thermal zone, 39, 42
TS Adapter and TS Adapter modular, 52
TS Adapter on a DIN rail, 54
TS Adapter on a wall, 55
TS Adapter SIM card, 53
wiring guidelines, 56, 57
Installation requirements, 27
Instance data block, 78
Instructions
ABS (absolute value), 173
ACOS (arc cosine or inverse cosine), 176
ADD (add), 170
adding inputs or outputs to LAD or FBD
instructions, 32
AND, 199
ASIN (arc sine or inverse sine), 176
ATAN (arc tangent or inverse tangent), 176
ATH (ASCII to hexadecimal), 224
ATTACH, 247
bit logic, 147
block move (MOVE_BLK), 178
CALCULATE, 30, 169
calendar, 207
CAN_DINT (cancel time delay interrupt), 253
CEIL (ceiling), 185

clock, 209
columns and headers, 33, 474
common parameters, 389
compare, 167
CONCAT (concatenate), 227
CONV (convert), 183
COS (cosine), 176
counters, 161
CTD (count down), 161
CTRL_PWM), 261
CTU (count up), 161
CTUD (count up and down), 161
data block control, 265
DataLogClose (close Data log), 274
DataLogCreate (create Data log), 270
DataLogNewFile (create Data log based on existing
Data log), 277
DataLogOpen (open Data log), 273
DataLogWite (write Data log), 275
date, 207
DEC (decrement), 173
DECO (decode), 200
DELETE (delete substring), 230
DETACH, 247
DeviceStates, 257
DIS_AIRT (disable alarm interrupt), 255
DIV (divide), 170
DPNRM_DG, 244
DPRD_DAT, 242
DPWR_DAT, 242
drag and drop, 29
drag and drop between editors, 34
EN_AIRT (enable alarm interrupt), 255
ENCO (encode), 200
EXP (natural exponential), 176
expandable instructions, 32
EXPT (general exponential), 176
favorites, 29
FieldRead, 180
FieldWrite, 180
FILL_BLK, 181
FIND (find substring), 233
floating-point math, 176
FLOOR, 185
force, 558
force operation, 559
FRAC (fraction), 176
GET, 412
GET_DIAG, 259
GetError, 195
GetErrorID, 197
HSC (high-speed counter), 287, 289

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673

Index

HTA (Hex to ASCII), 225
IN_RANGE (within a range), 168
INC (increment), 173
INSERT (insert substring), 231
inserting, 29
INV (invert), 199
JMP, 189
JMP_LIST, 190
Label, 189
LED status, 256
LEFT (left substring), 228
LEN (length), 227
limit, 175
LN (natural logarithm), 176
MAX (maximum), 174
MC_Halt, 323
MC_Home, 321
MC_MoveAbsolute, 325
MC_MoveJog, 331
MC_MoveRelative, 327
MC_MoveVelocity, 329
MC_Power, 317
MC_Reset, 320
MID (middle substring), 228
MIN (minimum), 174
MOD (modulo), 171
ModuleStates, 258
monitor, 553, 554
MOVE, 178
MUL (multiply), 170
MUX (multiplex), 202
N_TRIG, 152
NEG (negation), 172
negative edge, 152
NORM_X (normalize), 186
NOT OK, 168
OK, 168
OR, 199
OUT_RANGE (outside of a range), 168
P_TRIG, 152
PID_Compact, 299
PORT_CFG (port configuration), 430
positive edge, 152
PROFIBUS distributed I/O, 410
PROFINET distributed I/O, 410
PUT, 412
QRY_CINT (query cyclic interrupt), 252
RALRM, 237
RCV_CFG (receive configuration), 433
RCV_PtP (receive Point-to-Point), 440
RCV_RST (receiver reset), 441
RD_LOC_T (read local time), 209

RD_SYS_T (read system time), 209
RDREC, 234
RE_TRIGR, 72, 194
REPLACE (replace substring), 232
reset, 150
return value (RET), 193
RIGHT (right substring), 228
ROL and ROR (rotate left and rotate right), 205
ROUND, 184
RT (reset timer), 153
run time meter, 211
S_CONV (value to string conversions), 215
S_MOV (string move), 214
SCALE_X (scale), 186
scaling analog values, 31
SEL (select), 201
SEND_CFG (send configuration), 431
SEND_PTP (send Point-to-Point data), 437
Set, 150
SET_CINT (set cyclic interrupt), 250
SET_TIMEZONE, 212
SGN_GET (get RS232 signals), 442
SGN_SET (set RS232 signals), 443
SHL and SHR (shift left and shift right), 204
SIN (sine), 176
SQR (square), 176
SQRT (square root), 176
SRT_DINT (start time delay interrupt), 253
status, 553, 554, 558
STP (stop PLC scan cycle), 195
STRG_VAL (string to value), 215
SUB (subtract), 170
SWAP, 182
SWITCH, 191
T_ADD (add time), 208
T_COMBINE (combine times), 209
T_CONFIG, 384
T_CONV (convert time), 207
T_DIFF (time difference), 208
T_SUB (subtract time), 208
TAN (tangent), 176
TCON, 372
TDISCON, 372
time, 207
timer, 153
timer operations, 157
TOF (off-delay timer), 153
TON (on-delay timer), 153
TONR (on-delay retentive timer), 153
TP (pulse timer), 153
TRCV, 372
TRCV_C, 366, 397

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Index

TRUNC (truncate), 184
TSEND, 372
TSEND_C, 366, 396
TURCV, 380
TUSEND, 380
UFILL_BLK (uninterruptible fill), 181
uninterruptible move (UMOVE_BLK), 178
USS status codes, 469
USS_DRV, 463
USS_PORT, 466
USS_RPM, 467
USS_WPM, 468
VAL_STRG (value to string), 215
versions of instructions, 33, 474
WR_SYS_T (write system time), 209
WRREC, 234
WWW (enable user-defined Web pages), 524
XOR (exclusive OR), 199
Inter-character gap, 452
Interrupts
ATTACH and DETACH, 247
CAN_DINT (cancel time delay interrupt), 253
interrupt latency, 67
overview, 66
SRT_DINT (start time delay interrupt), 253
Intro standard Web page, 495
Invert (INV), 199
IP address, 119
assigning, 115, 121
assigning online, 117
configuring, 119
configuring the online CPU, 549
device configuration, 107
MAC address, 119
IP router, 119
ISO on TCP
ad hoc mode, 365
ISO on TCP protocol, 364
Isolation guidelines, 57
ISO-on-TCP
connection configuration, 110
connections and port IDs, 362
parameters, 113

J
JavaScript restrictions, standard Web pages, 505
JMP, 189
JMP_LIST, 190
JMPN, 189

K
Know-how protection
password protection, 139

L
Label, 189
LAD (ladder logic)
monitor, 553, 554
overview, 136
program editor, 554
status, 553, 554, 558
Lamp loads, 58
Languages, user-defined Web pages, 537
Latency, 67
LED (Get LED status), 256
LED indicators
communication interface, 425, 545
CPU status, 545
LED instruction, 256
LEFT (left substring), 228
LEN (length), 227
Length
message, 453
Length m, 453
Length n, 453
LENGTH parameter, SEND_PTP, 439
Limit, 175
Linear programming, 128
LN (natural logarithm), 176
Load memory, 18
CPU 1211C, 566
CPU 1212C, 574
CPU 1214C, 582
memory card, 95
program card, 95
transfer card, 95
Load memory, user-defined Web pages, 526
Local time
RD_LOC_T (read local time), 209
Local/Partner connection, 360
Logging in/out
standard Web pages, 495
Lost password, 102

M
MAC address, 119, 122
Manual fragment DB control, 541
Manuals, 4
Maritime approval, 563

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675

Index

Master polling architecture, 455
Math, 30, 169, 170
MAX (maximum), 174
Maximum message length, 452
MB_COMM_LOAD, 474
MB_MASTER, 477
MB_SLAVE, 482
MC_Halt, 323
MC_Home, 321
MC_MoveAbsolute, 325
MC_MoveJog, 331
MC_MoveRelative, 327
MC_MoveVelocity, 329
MC_Power, 317
MC_Reset, 320
Memory
clock memory, 76
I (process image input), 80
L (local memory), 78
load memory, 74
M (bit memory), 82
memory card does not contain force values, 95
monitoring memory usage, 550
peripheral input addresses (force table), 558
Q (process image output), 81
retentive memory, 74
system memory, 76
Temp memory, 82
work memory, 74
Memory areas
addressing Boolean or bit values, 79
immediate access, 79
process image, 79
Memory card
configure the startup parameters, 97
empty transfer card for a lost password, 102
inserting into CPU, 96
lost password, 102
operation, 95
order number, 651
overview, 95
program card, 100
specifications, 651
transfer card, 98
Memory locations, 78, 80
Message configuration
instructions, 454
receive, 448
transmit, 447
Message end, 450
Message length, 452
Message start, 448

MID (middle substring), 228
MIN (minimum), 174
Miscellaneous PtP parameter errors, 429
MOD (modulo), 171
MODBUS
MB_COMM_LOAD, 474
MB_MASTER, 477
MB_SLAVE, 482
Modbus master example, 488
Modbus slave example, 489
versions, 33, 474
Modifying
memory card does not contain force values, 95
program editor status, 554
watch table, 555
Modifying variables from PC, 501
Module information standard Web page, 498
Modules
CB 1241 RS485, 647
CM 1241 RS232, 651
CM 1241 RS485, 648
communication board (CB), 22
communication module (CM), 22
communication processor (CP), 22
comparison chart, 20
configuring parameters, 108
CPU 1211C specifications, 566
CPU 1212C specifications, 574
CPU 1214C specifications, 582
SB 1221 DI 4, 200 kHz, 617
SB 1222 DQ 4, 200 kHz, 200 kHz, 619
SB 1223 DI 2 / DQ 2, 623
SB 1223 DI 2 / DQ 2, 200 kHz, 621
SB 1231 AI 1 x 12 bit, 625
SB 1231 AI 1 x 16 bit RTD, 635
SB 1231 AI 1 x 16 bit Thermocouple signal
board, 631
SB 1232 AQ 1x12 bit, 628
signal board (SB), 22
signal module (SM), 22
SM 1221, 590
SM 1222, 593
SM 1223, 596
SM 1231 AI 4 x 16 bit TC, 608
SM 1231 AI 4 x RTD x 16 bit, 612
SM 1231 AI 8 x 13 bit, 600
SM 1231 AI 8 x 16 bit TC signal module, 608
SM 1231 AI 8 x RTD x 16 bit, 612
SM 1232 AQ 2 x 14bit, 602
SM 1232 AQ 4 x 14bit, 602
SM 1234 AI 4 x 13 bit / AQ 2 x 14 bit, 603
thermal zone, 39, 42

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Index

ModuleStates, 258
Monitor
capturing values of a DB, 554
resetting the start values of a DB, 554
Monitoring
cycle time, 550
force operation, 559
force table, 558
LAD status, 553, 554
LED instruction, 256
memory card does not contain force values, 95
memory usage, 550
watch table, 553, 555
Monitoring the program, 144
Monitoring variables from PC, 501
Motion control
configuring the axis, 314
hardware and software limit switches, 334
homing (sequence for active homing), 340
homing configuration parameters, 338
homing the axis, 337
MC_Halt, 323
MC_Home, 321
MC_MoveAbsolute, 325
MC_MoveJog, 331
MC_MoveRelative, 327
MC_MoveVelocity, 329
MC_Power, 317
MC_Reset, 320
overview, 312
Mounting
airflow, 39
clearance, 39
communication board (CB), 45
communication module (CM), 48
cooling, 39
CPU, 44
dimensions, 42
expansion cable, 50
grounding, 57
guidelines, 39
inductive loads, 59
isolation, 57
lamp loads, 58
overview, 43
signal board (SB), 45
signal module (SM), 46
terminal block connector, 49
thermal zone, 39, 42
wiring guidelines, 56, 57
MOVE, 178
MRES

operator panel, 35
MUL (multiply), 170
Multi-node connections
connection types, 415
Ethernet protocols, 415
Multiple AWP variable definitions, 520
MUX (multiplex), 202
My Documentation Manager, 4

N
N_TRIG, 152
NEG (negation), 172
Negative edge, 152
Nesting depth, 61
Network communication, 390
Network connection
configuration, 109
multiple CPUs, 393, 395, 399, 408
Network time protocol (NTP), 123
NORM_X (normalize), 186
Normalizing analogs, 187
NOT OK instruction, 168
Numbers
binary, 85
integer, 86
real, 86

O
Off-delay (TOF), 153
operation, 157
OK instruction, 168
On-delay delay (TON), 153
operation, 157
On-delay retentive (TONR), 153
operation, 157
Online
assigning an IP address, 117
capturing values of a DB, 554
comparing and synchronizing, 551
cycle time, 550
diagnostics buffer, 551
force, 558
force operation, 559
going online, 547
IP address, 549
memory usage, 550
monitor, 553
operating panel, 550
operator panel, 35

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677

Index

resetting the start values of a DB, 554
RUN/STOP buttons, 35
status, 553, 554
time of day, 549
tools, 552
watch table, 553, 554, 555
Online device names
PROFINET IO, 548
OPC, 421
Open User Communication instructions return
values, 389
Operating mode, 35
changing STOP/RUN, 550
operating modes of the CPU, 63
Operator panel, 35
operating modes of the CPU, 63
Operator panels, 25
OR, 185
Order numbers
Communication interfaces (CM, CB and CP), 660,
661
connector blocks, 662
Connectors and terminal connections, 661
CPUs, 659
CSM 1277 Ethernet switch, 661
documentation, 663
Expansion cables, 662
HMI basic panels, 662
memory cards, 662
PM 1207 power supply, 661
programming software, 663
Signal boards (SB), 659
Signal modules (SM), 660
simulators, 662
STEP 7, 663
visualization software, 663
WinCC, 663
Organization block
call, 66
calling code blocks within the user program, 129
capturing the status of a code block, 35
configuring operation, 131
creating, 131
function, 66
know-how protection, 139
linear and structured programming, 128
multiple cyclic, 131
overview, 61
priority classes, 66
processing, 130
restoring the status of a code block, 35
startup processing, 65

OUT_RANGE (outside of a range), 168
Output parameters, 132
configuring pulse channels, 264
pulse outputs, 263

P
P_TRIG, 152
Panels (HMI), 25
Parameter assignment, 132
Parameters configuration
LENGH and BUFFER for SEND_PTP, 439
receive, 398
transmit, 397
Parity, 445
Passive/active communication
configuring the partners, 110
connections and port IDs, 362
parameters, 113
Password protection
access to the CPU, 138
binding to a CPU or memory card, 140
code block, 139
copy protection, 140
CPU, 138
empty transfer card, 102
lost password, 102
Peripheral access alarms, 401
PID
overview, 296
PID_3STEP, 302
PID_3Step algorithm, 297, 302
PID_Compact, 299
PID_Compact algorithm, 296, 299
PLC
add modules, 106
assigning an IP address to an online CPU, 117
communication load, 73
comparing and synchronizing, 551
copying blocks from an online CPU, 142
CPU 1211C, 566
CPU 1212C, 574
CPU 1214C, 582
cycle time, 73
cycle time, 73
device configuration, 103
download, 142
expansion cable, 50
force, 558
force operation, 559
HSC configuration, 295
installation, 43, 44
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Index

know-how protection, 139
memory card, 95, 651
monitoring, 553
operating modes, 63
overview of the CPU, 17
power budget, 40
RD_LOC_T (read local time), 209
RD_SYS_T (read system time), 209
run time meter, 211
startup processing, 65
system design, 127
terminal block connector, 49
time synchronization property, 124
using blocks, 128
watch table, 555
WR_SYS_T (write system time), 209
Podcasts, 4
Pointer
pointer overview, 91
Pointers
Any data type, 93
Pointer data type, 92
Variant data type, 94
Point-to-Point communication, 427
Point-to-Point programming, 454
Polling architecture, 455
Port configuration, 444
errors, 431
instructions, 454
PtP example program, 456
Port number, 364
Port numbers
restricted, 390
PORT_CFG (port configuration), 430
Portal view, 28
Positive edge, 152
Power budget, 40
example, 656
form for calculations, 657
overview, 655
Power requirements
calculating a power budget, 656
form for calculations, 657
power budget, 655
Priority
priority class, 66
priority in processing, 67
Priority class, 66
Process image
force, 558
force operation, 559
monitor, 553, 554

status, 553, 554, 558
PROFIBUS
add CM 1243-5 (DP master) module, 407
add DP slave, 407
CM 1242-5 (DP slave) module, 402
CM 1243-5 (DP master) module, 402
distributed I/O instructions, 410
DPNRM_DG, 244
DPRD_DAT, 242
DPWR_DAT, 242
GET, 412
master, 402
network connection, 109, 408
PROFIBUS address, 408
PROFIBUS address properties, 409
PUT, 412
RALRM, 237
RDREC, 234
S7 connection, 415
slave, 402
WRREC, 234
PROFIBUS address, 408
configuring, 408
PROFINET
ad hoc mode, 365
configuring communication between CPU and HMI
device, 392
configuring the IP address, 107
connections and port IDs, 362
CPU-to-CPU communication, 394
device naming and addressing, 125
diagnostics, 402
distributed I/O instructions, 410
DPRD_DAT, 242
DPWR_DAT, 242
Ethernet address properties, 120
GET, 412
IP address, 119
IP address assignment, 125
MAC address, 119
network connection, 109, 393, 395, 399
number of communication connections, 360
overview, 364
PLC-to-PLC communication, 394
PUT, 412
RALRM, 237
RDREC, 234
S7 connection, 415
system start-up time, 124
T_CONFIG, 384
TCON, 372
TDISCON, 372

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679

Index

testing a network, 121
time synchronization, 107
time synchronization property, 124
TRCV, 372
TRCV_C, 366
TSEND, 372
TSEND_C, 366
TURCV, 380
TUSEND, 380
types of communication, 359
WRREC, 234
PROFINET IO
Adding a device, 398
Assigning a CPU, 399
Assigning device names, 399
Assigning device names online, 548
Device names, 399
Devices, 398
Online device names, 548
PROFINET RT, 364
Program
binding to a CPU or memory card, 140
calling code blocks within the user program, 129
capturing the status of a code block, 35
capturing values of a DB, 554
copying blocks from an online CPU, 142
download, 142
linear and structured programs, 128
memory card, 95
organization block (OB), 130
password protection, 139
priority class, 66
resetting the start values of a DB, 554
restoring the status of a code block, 35
Program card
configure the startup parameters, 97
creating, 100
inserting into CPU, 96
operation, 95
order number, 651
overview, 95
Program editor
capturing the status of a code block, 35
capturing values of a DB, 554
monitor, 554
resetting the start values of a DB, 554
restoring the status of a code block, 35
status, 554
Program execution, 61
Program information
In the call structure, 146
Program structure, 129

calling code blocks, 129
Programming
adding inputs or outputs to LAD or FBD
instructions, 32
binding to a CPU or memory card, 140
block calls, 61
calling code blocks within the user program, 129
comparing and synchronizing code blocks, 551
counters, 161
data block (DB), 61
drag and drop between editors, 34
expandable instructions, 32
favorites, 29
FBD (function block diagram), 137
function (FC), 132
function block (FB), 61, 132
initial value of an FB, 132
inserting instructions, 29
instance data block (DB), 132
LAD (ladder), 136
linear program, 128
operating modes of the CPU, 63
organization block (OB), 130
PID overview, 296
PID_3STEP, 302
PID_3Step algorithm, 297, 302
PID_Compact, 299
PID_Compact algorithm, 296, 299
power flow (EN and ENO), 137
priority class, 66
PtP instructions, 454
RD_LOC_T (read local time), 209
RD_SYS_T (read system time), 209
run time meter, 211
structured program, 128
types of code blocks, 61
unplugged modules, 38
unspecific CPU, 105
valid FC, FB, and DB numbers, 61
WR_SYS_T (write system time), 209
Programming user-defined Web page language
switch, 538
Project
access protection, 138
binding to a CPU or memory card, 140
comparing and synchronizing, 551
download, 142
empty transfer card, 102
lost password, 102
program card, 100
protecting a code block, 139
restricting access to a CPU, 138

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Index

transfer card, 98
Project view, 28
Protection class, 565
Protection level
binding to a CPU or memory card, 140
code block, 139
CPU, 138
lost password, 102
Protocol
communication, 427
freeport, 427
ISO on TCP, 364
Modbus, 427
PROFINET RT, 364
TCP, 364
UDP, 364
USS, 427
PTO (pulse train output)
cannot be forced, 559
configuring pulse channels, 264
CTRL_PWM, 261
operation, 263
PtP communication, 456
configuring parameters, 447
configuring ports, 444
example program, 456
example program configuration, 456
example program, running, 459
example program, STEP 7 programming, 458
programming, 454
terminal emulator for example program, 459
PtP error classes, 429
PtP instruction return values, 428
Pulse delay (TP), 153
operation, 157
Pulse outputs, 263
PUT, 412
configuring the connection, 111
PWM (pulse width modulation)
cannot be forced, 559
configuring pulse channels, 264
CTRL_PWM, 261
operation, 263

Q
Q memory
configuring pulse channels, 264
pulse outputs, 263
QRY_CINT (query cyclic interrupt), 252
Queuing, 67
Quotation mark conventions, Web server, 521

R
RALRM, 239
Rated voltages, 565
RCV_CFG (receive configuration), 433
RCV_PTP (receive Point-to-Point), 440
RCV_RST (receiver reset), 441
RD_LOC_T (read local time), 209
RD_SYS_T (read system time), 209
RDREC, 239
RE_TRIGR, 72, 194
READ_DBL, 265
Reading HTTP variables, 513
Receive configuration errors, 436
Receive message configuration, 448
PtP example program, 457
Receive parameters configuration, 398
Receive runtime return values, 440
Referencing enum types, user-defined Web pages, 517
Refreshing user-defined Web pages, 509
Relay electrical service life, 566
REPLACE (replace substring), 232
Replacing modules, 38
Requirements, installation, 27
Reset, 320
Reset timer (RT), 153
Resetting the start values of a DB, 554
Restoring the status of a code block, 35
Restricted TSAPs and port numbers, 390
Retentive memory, 18
CPU 1211C, 566
CPU 1212C, 574
CPU 1214C, 582
Return value (RET), 193
Return values
Open User Communication instructions, 389
PtP instructions, 428
RIGHT (right substring), 228
ROL and ROR (rotate left and rotate right), 205
ROUND, 184
Router IP address, 120
RS232 and RS485 communication modules, 425
RT (reset timer), 153
RTS, 445
RTS always on, 446
RTS Off delay, 447
RTS On delay, 447
RTS switched, 445
RUN mode, 63, 65, 550
force, 558
force operation, 559
operator panel, 35
toolbar buttons, 35

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Index

Run time meter, 211
RUN to STOP transition, 78
RUN/STOP buttons, 35

S
S_CONV (value to string conversions), 215
S_MOV (string move), 214
S7 communication
configuring the connection, 111
S7-1200
access protection, 138
add modules, 106
add new device, 104
airflow, 39
capturing the status of a code block, 35
capturing values of a DB, 554
clearance, 39
communication board (CB), 22
communication load, 73
communication module (CM), 22
communication processor (CP), 22
compare code blocks, 551
comparison chart of CPU models, 18
configuring the CPU parameters, 107
configuring the modules, 108
cooling, 39
CPU installation, 44
cycle time, 73
device configuration, 103
empty transfer card for a lost password, 102
Ethernet port, 119
expansion cable, 50
force, 558
force operation, 559
grounding, 57
HMI devices, 25
HSC configuration, 295
inductive loads, 59
installation, 43
installing a CB, 45
installing a CM, 48
installing an SB, 45
installing an SM, 46
IP address, 119
isolation guidelines, 57
know-how protection, 139
lamp loads, 58
lost password, 102
MAC address, 119
memory card, 651
modules, 20

monitoring, 553
mounting dimensions, 42
network connection, 109
operating modes, 63
operation, 555
operator panel, 35
overview of the CPU, 17
password protection, 138
power budget, 40
PROFIBUS, 408
PROFIBUS address, 408
PROFIBUS port, 408
PROFINET, 119
program card, 100
pulse outputs, 263
resetting the start values of a DB, 554
restoring the status of a code block, 35
RUN/STOP buttons, 35
signal board (SB), 22
signal module (SM), 22
startup parameters, 97
startup processing, 65
terminal block connector, 49
thermal zone, 39, 42
transfer card, 98
TS Adapter, 20
wiring guidelines, 56, 57
SB 1221
SB 1221 DI 4, 200 kHz wiring diagram, 618
SB 1222
SB 1222 DQ 4 x 24 VDC, 200 kHz wiring
diagram, 620
SB 1223
SB 1223 DI 2 / DQ 2 wiring diagram, 625
SB 1223 DI 2 / DQ, 200 kHz wiring diagram, 623
SB 1231 AI 1 x 16 bit Thermocouple
Filter selection table, 634
SB 1232
SB 1232 AQ 1 x 12 bit wiring diagram, 628
SCALE_X (scale), 186
Scaling analogs, 31, 187
Scan cycle
force, 558
force operation, 559
Scan cycle time
overview, 72
SCL (Structured Control Language)
ABS (absolute value), 173
ACOS (arc cosine or inverse cosine), 176
AND, 199
ASIN (arc sine or inverse sine), 176
ATAN (arc tangent or inverse tangent), 176

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Index

ATH (ASCII to hexadecimal), 224
ATTACH and DETACH, 247
bit logic, 147
calling blocks, 129
CAN_DINT (cancel time delay interrupt), 253
CEIL (ceiling), 185
compare, 167
CONCAT (concatenate), 227
CONV (convert), 183
COS (cosine), 176
counters, 161
CTD (count down), 161
CTU (count up), 161
CTUD (count up and down), 161
DataLogClose (close Data log), 274
DataLogCreate (create Data log), 270
DataLogNewFile (create Data log based on existing
Data log), 277
DataLogOpen (open Data log), 273
DataLogWrite (write Data log), 275
DEC (decrement), 173
DECO (decode), 200
DELETE (delete substring), 230
DeviceStates, 257
DIS_AIRT (disable alarm interrupt), 255
EN and ENO (power flow), 137
EN_AIRT (enable alarm interrupt), 255
ENCO (encode), 200
EXP (natural exponential), 176
EXPT (general exponential), 176
FILL_BLK, 181
FIND (find substring), 233
floating-point math, 176
FLOOR, 185
FRAC (fraction), 176
GET_DIAG, 259
HTA (hexadecimal to ASCII), 225
IN_RANGE (within a range), 168
INC (increment), 173
INSERT (insert substring), 231
INV (invert), 199
JMP_LIST, 190
LED status, 256
LEFT (left substring), 228
LEN (length), 227
LIMIT, 175
LN (natural logarithm), 176
math, 170
math (floating-point), 176
MAX (maximum), 174
MC_Halt, 323
MC_Home, 321

MC_MoveAbsolute, 325
MC_MoveJog, 331
MC_MoveRelative, 327
MC_MoveVelocity, 329
MC_Power, 317
MC_Reset, 320
MID (middle substring), 228
MIN (minimum), 174
MOD (modulo), 171
ModuleStates, 258
move, 178
MUX (multiplex), 202
N_TRIG, 152
NEG (negation), 172
NORM_X (normalize), 186
NOT OK, 168
OK, 168
OR, 199
OUT_RANGE (outside of a range), 168
P_TRIG, 152
PID overview, 296
PID_3STEP, 302
PID_3Step algorithm, 297, 302
PID_Compact, 299
PID_Compact algorithm, 296, 299
QRY_CINT (query cyclic interrupt), 252
RD_LOC_T (read local time), 209
RD_SYS_T (read system time), 209
REPLACE (replace substring), 232
RIGHT (right substring), 228
ROL and ROR (rotate left and rotate right), 205
round, 184
run time meter, 211
S_CONV (value to string conversions), 215
S_MOV (move string), 214
SCALE_X (scale), 186
SEL (select), 201
Set and Reset, 150
SET_CINT (set cyclic interrupt), 250
SET_TIMEZONE (set time zone), 212
SHL and SHR (shift left and shift right), 204
SIN (sine), 176
SQR (square), 176
SQRT (square root), 176
SRT_DINT (start time delay interrupt), 253
STRG_VAL (string to value), 215
swap, 182
SWITCH, 191
T_ADD (add time), 208
T_COMBINE (combine times), 209
T_CONV (convert time), 207
T_DIFF (time difference), 208

S7-1200 Programmable controller
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683

Index

T_SUB (subtract time), 208
TAN (tangent), 176
timer operations, 157
timers, 153
truncate, 184
UFILL_BLK (uninterruptible fill), 181
VAL_STRG (value to string), 215
WR_SYS_T (write system time), 209
XOR (exclusive OR), 199
Security
access protection, 138
binding to a CPU or memory card, 140
copy protection, 140
CPU, 138
know-how protectionf for a code block, 139
lost password, 102
SEL (select), 201
Send message configuration, 447
Send parameters configuration, 110, 397
SEND_CFG (send configuration), 431
SEND_PTP (send Point-to-Point data), 437
LENGH and BUFFER parameters, 439
Serial communication, 427
Service and support, 3
Set, 150
SET_CINT (set cyclic interrupt), 250
SET_TIMEZONE (set time zone), 212
Settings, 33
SGN_GET (get RS232 signals), 442
SGN_SET (set RS232 signals), 443
SHL and SHR (shift left and shift right), 204
Siemens security certificate, Web pages, 496, 506
Siemens technical support, 3
siemens_automation_language cookie, 538
Signal board (SB)
add modules, 106
analog output representation (current), 607, 630
analog output representation (voltage), 608, 631
configuration of parameters, 108
input representation (voltage), 572, 580, 588, 607,
630
installation, 45
overview, 22
power requirements, 655
removal, 45
SB 1221 DI 4, 200 kHz, 617
SB 1222 DQ, 200 kHz, 619
SB 1223 DI 2 / DQ 2, 623
SB 1223 DI 2 / DQ 2, 200 kHz, 621
SB 1231 AI 1 x 12 bit, 625
SB 1231 AI 1 x 16 bit RTD, 635
SB 1231 AI 1 x 16 bit Thermocouple, 631

SB 1232 AQ 1x12 bit, 628
step response times, 629
Signal handling errors, 442, 444
Signal module (SM)
add modules, 106
analog input representation (voltage), 572, 580,
588, 607, 630
analog output representation (current), 607, 630
analog output representation (voltage), 608, 631
configuration of parameters, 108
expansion cable, 50
installation, 46
overview, 22
power requirements, 655
removal, 47
SM 1221, 590
SM 1222, 593
SM 1223, 596
SM 1223 specifications, 597
SM 1231 AI 4 x 13 bit, 600
SM 1231 AI 4 x 16 bit TC, 608
SM 1231 AI 4 x RTD x 16 bit, 612
SM 1231 AI 8 x 16 bit TC, 608
SM 1231 AI 8 x RTD x 16 bit, 612
SM 1232 AQ 2 x 14bit, 602
SM 1232 AQ 4 x 14bit, 602
SM 1234 AI 4 x 13 bit / AQ 2 x 14 bit, 603
step response times, 606
Simulators, 653
SIN (sine), 176
Slave polling architecture, 455
SM 1231 RTD
selection tables, 616, 639
SM and SB
comparison chart, 20
device configuration, 103
SMS, 420
Software flow control, 446
Special characters
User-defined Web pages, 521
Specifications
analog input representation (voltage), 572, 580,
588, 607, 630
analog output representation (current), 607, 630
analog output representation (voltage), 608, 631
ATEX approval, 562
CB 1241 RS485, 647
CE approval, 561
CM 1241 RS232, 651
CM 1241 RS485, 648
CPU 1211C, 566
CPU 1212C, 574

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Index

CPU 1214C, 582
C-Tick approval, 563
cULus approval, 562
electromagnetic compatibility (EMC), 563
environmental conditions, 564
FM approval, 562
general technical specifications, 561
industrial environments, 563
input simulators, 653
maritime approval, 563
memory cards, 651
protection, 565
rated voltages, 565
relay electrical service life, 566
SB 1221 DI 4, 200 kHz, 617
SB 1222 DQ 4, 200 kHz, 619
SB 1223 DI 2 / DQ 2, 623
SB 1223 DI 2 x / DQ 2, 200 kHz, 621
SB 1231 AI 1 x 12 bit, 625
SB 1231 AI 1 x 16 bit RTD, 635
SB 1231 AI 1 x 16 bit RTD wiring diagram, 637
SB 1231 AI 1 x 16 bit Thermocouple, 631
SB 1231 AI 1 x 16 bit thermocouple wiring
diagram, 635
SB 1231 AI x 12 bit wiring diagram, 627
SB 1232 AQ 1x12 bit, 628
SM 1221 signal module, 590
SM 1221 wiring diagram, 591
SM 1222 signal module, 593
SM 1222 wiring diagram, 593
SM 1223 signal module, 596, 597
SM 1223 wiring diagram, 596, 597
SM 1231 AI 4 x 13 bit, 600
SM 1231 AI 4 x 16 bit TC signal module, 608
SM 1231 AI 4 x 16 bit TC wiring diagram, 610
SM 1231 AI 4 x RTD x 16 bit signal module, 612
SM 1231 AI 8 x 16 bit TC signal module, 608
SM 1231 AI 8 x 16 bit TC wiring diagram, 610
SM 1231 AI 8 x RTD x 16 bit signal module, 612
SM 1231 RTD 4 x 16 bit wiring diagram, 614
SM 1231 RTD 8 x 16 bit wiring diagram, 614
SM 1232 AQ 2 x 14bit, 602
SM 1232 AQ 4 x 14bit, 602
SM 1234 AI 4 x 13 bit / AQ 2 x 14 bit, 603
step response times (CPU), 572, 580, 588
step response times (SB), 629
step response times (SM), 606
wiring diagrams SM 1231 analog input, 601
wiring diagrams SM 1232 analog output, 603
wiring diagrams SM 1234 analog input/output, 605
SQR (square), 176
SQRT (square root), 176

SRT_DINT (start time delay interrupt), 253
Standard Web pages, 491
accessing from PC, 492
changing operating mode, 496
communication, 500
cookie restrictions, 506
Data Logs, 503
Diagnostic, 497
Identification, 497
Intro, 495
JavaScript restrictions, 505
layout, 494
logging in and out, 495
Module information, 498
secure access, 493
Start, 496
Variable Status, 501
Start conditions, 448
Start message character, 449
Start standard Web page, 496
STARTUP mode
force, 558
force operation, 559
startup processing, 65
Startup parameters, 97
Status
LED indicators, 545
LED indicators (communication interface), 425
LED instruction, 256
STEP 7
add modules, 106
add new device, 104
Adding a PROFINET IO device, 398
adding inputs or outputs to a LAD or FBD
instruction, 32
assigning an IP address to an online CPU, 117
block calls, 61
calling code blocks within the user program, 129
capturing the status of a code block, 35
capturing values of a DB, 554
changing the settings, 33
communication load, 73
comparing and synchronizing, 551
configuring the CPU, 107
configuring the modules, 108
copying blocks from an online CPU, 142
counters, 161
cycle time, 73
cycle time, 73
data block (DB), 61
device configuration, 103
download, 142

S7-1200 Programmable controller
System Manual, 04/2011, A5E02486680-03

685

Index

drag and drop between editors, 34
Ethernet port, 119
expandable inputs or outputs, 32
favorites, 29
force, 558
force operation, 559
function (FC), 132
function block (FB), 61, 132
HSC configuration, 295
initial value of an FB, 132
inserting instructions, 29
instance data block (DB), 132
linear and structured programs, 128
memory card, 95, 651
monitoring, 553, 554
network connection, 109
operating modes, 63
operation, 555
operator panel, 35
password protection, 139
Portal view, 28
priority class (OB), 66
PROFIBUS, 408
PROFIBUS port, 408
PROFINET, 119
program card, 95
Project view, 28
RD_LOC_T (read local time), 209
RD_SYS_T (read system time), 209
resetting the start values of a DB, 554
restoring the status of a code block, 35
run time meter, 211
RUN/STOP buttons, 35
startup processing, 65
time synchronization property (PROFINET), 124
transfer card, 95
types of code blocks, 61
unplugged modules, 38
valid FC, FB, and DB numbers, 61
WR_SYS_T (write system time), 209
STEP 7 programming
PtP example program, 458
user-defined Web pages, 524
STEP 7 web pages, 4
Stop bits, 445
STOP mode, 550
enable outputs in STOP mode, 557
force, 558
force operation, 559
operator panel, 35
toolbar buttons, 35
STP (stop PLC scan cycle), 195

STRG_VAL (string to value), 215
String
S_MOVE (string move), 214
string data overview, 214
String data type, 89
string operations overview, 226
Structured programming, 128, 129
calling blocks, 129
SUB (subtract), 170
Subnet mask, 119
Support, 3
SWAP, 182
SWITCH, 191
Switching languages, user-defined Web pages, 537
Synchronization
synchronizing blocks with the online CPU, 551
time synchronization property (PROFINET), 124
System clock
RD_LOC_T (read local time), 209
RD_SYS_T (read system time), 209
WR_SYS_T (write system time), 209
System memory byte, 77
System requirements, 27

T
T_ADD (add time), 208
T_COMBINE (combine times), 209
T_CONFIG, 384
T_CONV (convert time), 207
T_DIFF (time difference), 208
T_SUB (subtract timet), 208
Tags
force, 558
force operation, 559
monitor, 553
status, 553, 558
TAN (tangent), 176
Task cards
columns and headers, 33, 474
TCON, 113
configuration, 110
connection parameters, 113
connections and port IDs, 362
TCON_Param, 113
TCP
ad hoc mode, 365
connection configuration, 110
connections and port IDs, 362
parameters, 113
protocol, 364
TCP/IP communication, 364
S7-1200 Programmable controller

686

System Manual, 04/2011, A5E02486680-03

Index

TDISCON, 372
Technical specifications, 561
Technical support, 3
Technological objects
HSC (high-speed counter), 289
Telecontrol, 417
TeleService via GPRS, 418, 422
Terminal block connector, 49
Terminal emulator for PtP example program, 459
Testing the program, 144
Thermal zone, 39, 42
Thermocouple
basic operation, 611, 633
cold junction compensation, 611, 633
SB 1231 Thermocouple filter selection table, 634
SB 1231 Thermocouple selection table, 634
SM 1231 Thermocouple filter selection table, 611
SM 1231 Thermocouple selection table, 611
TIA Portal
Portal view, 28
Project view, 28
Time
DTL (date and time long data type), 88
RD_LOC_T (read local time), 209
RD_SYS_T (read system time), 209
SET_TIMEZONE (set time zone), 212
T_ADD (add time), 208
T_COMBINE (combine times), 209
T_CONV (convert time), 207
T_DIFF (time difference), 208
T_SUB (subtract time), 208
Time data type, 87
TOD (time of day data type), 87
WR_SYS_T (write system time), 209
Time delay interrupt), 253
Time of day
configuring the online CPU, 549
Time synchronization property, 124
Timers
operation, 157
quantity, 19, 568, 576, 584
RT (reset timer), 153
size, 19, 568, 576, 584
TOF (off-delay timer), 153
TON (on-delay delay timer), 153
TONR (on-delay retentive) timer, 153
TP (pulse delay timer), 153
Transfer card, 98
configure the startup parameters, 97
empty transfer card for a lost password, 102
inserting into CPU, 96
lost password, 102

operation, 95
order number, 651
overview, 95
Transmission block (T-block), 395
Transmit configuration errors, 432
Transmit message configuration, 447
PtP example program, 457
Transmit runtime errors, 438
TRCV, 372
ad hoc mode, 365
connections and port IDs, 362
TRCV_C, 366
ad hoc mode, 365
configuration, 110
connection parameters, 113
connections and port IDs, 362
TRCV_C instruction configuration, 398
Triggering values in the watch table, 556
Troubleshooting
diagnostics buffer, 551
LED indicators, 545
TRUNC (truncate), 184
TS Adapter, 53
installing a TS Adapter modular, 52
installing on a DIN rail, 54
installing on a wall, 55
SIM card, 53
TSAP, 390
TSAP (transport service access points), 112, 366, 395,
416
TSAPs
restricted, 390
TSEND, 372
connections and port IDs, 362
TSEND_C, 366
configuration, 110
connection parameters, 113
connections and port IDs, 362
TSEND_C, 366
TSEND_C instruction configuration, 397
TURCV, 380
configuration, 110
connection parameters, 113
TUSEND, 380
configuration, 110
parameters, 113

U
UDP
connection configuration, 110
parameters, 113

S7-1200 Programmable controller
System Manual, 04/2011, A5E02486680-03

687

Index

UDP protocol, 364
UFILL_BLK (uninterruptible fill), 181
Uninterruptible move (UMOVE_BLK), 178
Unplugged modules, 38
Unspecific CPU, 105
Updating user-defined Web pages, 509
Uploading
comparing and synchronizing blocks, 551
copying blocks from an online CPU, 142
user program, 142
User interface
Portal view, 28
Project view, 28
User program
adding inputs or outputs to LAD or FBD
instructions, 32
binding to a CPU or memory card, 140
calling code blocks within the user program, 129
copying blocks from an online CPU, 142
download, 142
drag and drop between editors, 34
expandable instructions, 32
favorites, 29
inserting instructions, 29
linear and structured programs, 128
memory card, 95
organization block (OB), 130
password protection, 139
program card, 95
transfer card, 95
User-defined Web pages, 521
accessing from PC, 526
activating and deactivating from control DB, 541
AWP commands for accessing S7-1200 data, 510
configuring, 522
creating fragments, 519
creating with HTML editor, 509
deleting program blocks, 524
downloading corresponding DBs, 525
enabling with WWW instruction, 524
example, 527
generating program blocks, 524
handling special characters, 521
HTML listing, 532
importing fragments, 520
load memory constraints, 526
manual fragment DB control, 541
multiple language configuration, 540
multiple languages, 537
programming in STEP 7, 524
reading special variables, 513
reading variables, 511

refreshing, 509
writing special variables, 514
writing variables, 512
USS protocol library
general drive setup inforamtion, 471
overview, 460
requirements for using, 461
status codes, 469
USS_DRV, 463
USS_PORT, 466
USS_RPM, 467
USS_WPM, 468

V
VAL_STRG (value to string), 215
Variable Status standard Web page, 501
Variables
monitoring and modifying from PC, 501
Versions of instructions, 33, 474
Visualization
HMI devices, 25

W
Wait time, 445
Watch table
enable outputs in STOP mode, 557
force, 144
memory card does not contain force values, 95
monitor, 553
operation, 555
trigger values, 556
Watchdog, 194
Web pages
STEP 7, 4
Web server, 504
constraints, 504
enabling, 492
Quotation mark conventions, 521
standard Web pages, 492
update rate, 492
Web server, user-defined Web pages, 508
Wiring diagrams
CPU 1211C, 574
CPU 1212C, 582
CPU 1214C, 590
SB 1221 DI 4, 200 kHz, 618
SB 1222 DQ 4, 200 kHz, 620
SB 1223 DI 2 / DQ 2, 200 kHz, 623
SB 1223 DI 2/ DQ 2, 625

S7-1200 Programmable controller

688

System Manual, 04/2011, A5E02486680-03

Index

SB 1231 AI 1 x 16 bit RTD, 637
SB 1231 AI 1 x 16 bit thermocouple, 635
SB 1231 AI x 12 bit, 627
SB 1232 AQ 1 x 12 bit, 628
SM 1221 signal module, 591
SM 1222 signal module, 593
SM 1223 signal module, 596, 597
SM 1231 AI 4 x 16 bit TC, 610
SM 1231 AI 8 x 16 bit TC, 610
SM 1231 analog input, 601
SM 1231 RTD 4 x 16 bit, 614
SM 1231 RTD 8 x 16 bit, 614
SM 1232 analog output, 603
SM 1234 analog input/output, 605
Wiring guidelines, 57
clearance for airflow and cooling, 39
grounding, 57
prerequisites, 56
Work memory, 18
CPU 1211C, 566
CPU 1212C, 574
CPU 1214C, 582
WR_SYS_T (write system time), 209
WRIT_DBL, 265
WRREC, 239
WWW (enable user-defined Web pages), 524

X
XON / XOFF, 446
XOR (exclusive OR), 199

S7-1200 Programmable controller
System Manual, 04/2011, A5E02486680-03

689

Index

S7-1200 Programmable controller

690

System Manual, 04/2011, A5E02486680-03

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Author : Microsystems JOCY
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Create Date : 2011:03:31 16:16:17-04:00
Keywords : "A5E02486680-03;, 04/2011", 6ES7298-8FA30-8BH0
Modify Date : 2011:05:05 08:18:50+02:00
Company-long : Siemens AG
Company-short : Siemens
Document-class : System Manual
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Edition : 04/2011
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Order-nr : A5E02486680-03
Print-year : 2010
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Title : S7-1200 Programmable controller
Description : System Manual
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