Logix 5000 Controllers Design Considerations Reference Manual, 1756-RM094K-EN-P

Logix 5000 Controllers Design Considerations Reference Manual, 1756-RM094K-EN-P

ControlLogix, GuardLogix, CompactLogix, Compact GuardLogix, SoftLogix

Logix 5000 Controllers Design Considerations Reference ...

2 Rockwell Automation Publication 1756-RM094K-EN-P - October 2020 Logix 5000 Controllers Important User Information Read this document and the documents listed in the additional resources section about installation, con…

1756-RM094 - Literature Library | Rockwell Automation

This manual contains new and updated information as indicated in the following table. Controller Family. Includes these controllers. 5580 controllers. ControlLogix ...

Original Instructions

ControlLogix, GuardLogix, CompactLogix, Compact GuardLogix, SoftLogix. Reference Manual. Original Instructions.

Original Document

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Logix 5000 Controllers Design Considerations
ControlLogix, GuardLogix, CompactLogix, Compact GuardLogix, SoftLogix

Reference Manual

Original Instructions

Logix 5000 Controllers
Important User Information
Read this document and the documents listed in the additional resources section about installation, configuration, and operation of this equipment before you install, configure, operate, or maintain this product. Users are required to familiarize themselves with installation and wiring instructions in addition to requirements of all applicable codes, laws, and standards. Activities including installation, adjustments, putting into service, use, assembly, disassembly, and maintenance are required to be carried out by suitably trained personnel in accordance with applicable code of practice. If this equipment is used in a manner not specified by the manufacturer, the protection provided by the equipment may be impaired. In no event will Rockwell Automation, Inc. be responsible or liable for indirect or consequential damages resulting from the use or application of this equipment. The examples and diagrams in this manual are included solely for illustrative purposes. Because of the many variables and requirements associated with any particular installation, Rockwell Automation, Inc. cannot assume responsibility or liability for actual use based on the examples and diagrams. No patent liability is assumed by Rockwell Automation, Inc. with respect to use of information, circuits, equipment, or software described in this manual. Reproduction of the contents of this manual, in whole or in part, without written permission of Rockwell Automation, Inc., is prohibited. Throughout this manual, when necessary, we use notes to make you aware of safety considerations.
WARNING: Identifies information about practices or circumstances that can cause an explosion in a hazardous environment, which may lead to personal injury or death, property damage, or economic loss.
ATTENTION: Identifies information about practices or circumstances that can lead to personal injury or death, property damage, or economic loss. Attentions help you identify a hazard, avoid a hazard, and recognize the consequence.
IMPORTANT Identifies information that is critical for successful application and understanding of the product. Labels may also be on or inside the equipment to provide specific precautions.
SHOCK HAZARD: Labels may be on or inside the equipment, for example, a drive or motor, to alert people that dangerous voltage may be present.
BURN HAZARD: Labels may be on or inside the equipment, for example, a drive or motor, to alert people that surfaces may reach dangerous temperatures.
ARC FLASH HAZARD: Labels may be on or inside the equipment, for example, a motor control center, to alert people to potential Arc Flash. Arc Flash will cause severe injury or death. Wear proper Personal Protective Equipment (PPE). Follow ALL Regulatory requirements for safe work practices and for Personal Protective Equipment (PPE).

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Rockwell Automation Publication 1756-RM094K-EN-P - October 2020

5580 Controller and 5380 Controllers
5480 Controller
5570 Controllers and 5370 Controllers

Table of Contents
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Summary of Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Additional Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Chapter 1
ControlLogix 5580 and GuardLogix 5580 Controllers . . . . . . . . . . . 11 CompactLogix 5380 and Compact GuardLogix 5380 Controllers. 12 Process Controllers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Controller Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Data Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Extended Data Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Programming Techniques. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Data Alignment Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Produced and Consumed Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Chapter 2
CompactLogix 5480 Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Controller Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Data Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Extended Data Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Programming Techniques. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Data Alignment Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Produced and Consumed Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Chapter 3
ControlLogix 5570 and GuardLogix 5570 Controllers . . . . . . . . . . . 21 CompactLogix 5370 and Compact GuardLogix 5370 Controllers. 22 Controller Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 CompactLogix 5370 and Compact GuardLogix 5370 Controllers. 23 Controller Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Determine Total Connection Requirements . . . . . . . . . . . . . . . . . 25 System Overhead Percentage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Manage the System Overhead Timeslice Percentage . . . . . . . . . . 28 I/O Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Data Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Programming Techniques. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Produced and Consumed Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

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Table of Contents
Logic Execution
Modular Programming Techniques
4

Chapter 4
Decide When to Use Tasks, Programs, and Routines . . . . . . . . . . . . . 31 Specify Task Priorities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Manage User Tasks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Pre-defined Tasks in ControlLogix and CompactLogix Process Controllers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Considerations that Affect Task Execution . . . . . . . . . . . . . . . . . . . . . . 34 Configure a Continuous Task . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Configure a Periodic Task . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Configure an Event Task . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Guidelines to Configure an Event Task. . . . . . . . . . . . . . . . . . . . . . 36 Additional Considerations for Periodic and Event Tasks. . . . . . 36 Access the Module Object . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Develop Application Code in Routines . . . . . . . . . . . . . . . . . . . . . . . . . 37 Comparison of Programming Languages . . . . . . . . . . . . . . . . . . . . 38 Programming Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Inline Duplication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Indexed Routine. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Buffered Routine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Controller Prescan of Logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Add-On Instruction Prescan Logic. . . . . . . . . . . . . . . . . . . . . . . . . . 40 Controller Postscan of SFC Logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Add-On Instruction Postscan Logic. . . . . . . . . . . . . . . . . . . . . . . . . 41 Timer Execution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 SFC Step Timer Execution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Edit an SFC Online . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Chapter 5
Guidelines for Code Reuse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Naming Conventions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Parameter Name Prefixes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Guidelines for Subroutines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Guidelines for User-defined Data Types. . . . . . . . . . . . . . . . . . . . . . . . . 51
Naming Conventions for User-Defined Data Types . . . . . . . . . . 51 UDT Member Order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 Guidelines for Add-On Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 Add-On Instruction Design Concepts . . . . . . . . . . . . . . . . . . . . . . 55 Naming Conventions for Add-On Instructions . . . . . . . . . . . . . . 55 Comparison of Subroutines and Add-On Instructions. . . . . . . . 55 Comparison of Partial Import/Export and Add-On Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 Guidelines for Program Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 Comparison of Program Parameters and Add-On Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 Compare Controller Organizer and Logical Organizer . . . . . . . . . . . 58
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Structure Logic According to Standards

Chapter 6
Physical Model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 Separate a Process Unit into Equipment Modules and Control Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 Physical Model Naming Conventions . . . . . . . . . . . . . . . . . . . . . . . 62
Procedural Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 Identify Operations and Phases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Procedural Control Modes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 Procedural Control States. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 Procedural Control Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Procedural Model Naming Conventions . . . . . . . . . . . . . . . . . . . . 68 State Model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

Produced and Consumed Data

Chapter 7
Guidelines for Produced and Consumed Tags . . . . . . . . . . . . . . . . . . . 72 Guidelines for Produced and Consumed Axis. . . . . . . . . . . . . . . . . . . . 73 Guidelines to Specify an RPI Rate for Produced and Consumed Tags. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 Guidelines to Manage Connections for Produced and Consumed Tags. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 Configure an Event Task Based on a Consumed Tag . . . . . . . . . . . . . 74 Compare Messages and Produced/Consumed Tags . . . . . . . . . . . . . . 74

Data Structures

Chapter 8
Guidelines for Data Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 Arrays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 Guidelines for Arrays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 Indirect Addresses of Arrays. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 Guidelines for Array Indexes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 Guidelines for User-defined Data Types (UDT) . . . . . . . . . . . . . . . . . 79 Select a Data Type for Bit Tags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 Serial Bit Addresses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 Guidelines for String Data Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 PLC-5/SLC 500 Access of Strings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 Configure Tags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 Guidelines for Base Tags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 Create Alias Tags. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 Guidelines for Data Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 Guidelines for Tag Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 Guidelines for Extended Tag Properties . . . . . . . . . . . . . . . . . . . . . . . . . 86 Tag Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 Protect Data Access Control at Tag Level . . . . . . . . . . . . . . . . . . . . . . . 87

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Communicate with I/O
Determine the Appropriate Network
Communicate with Other Devices Alarms

Chapter 9
Buffer I/O Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 Guidelines to Specify an RPI Rate for I/O Modules . . . . . . . . . . . . . . 90 Communication Formats for I/O Modules. . . . . . . . . . . . . . . . . . . . . . 91
Direct Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 Rack-optimized Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 Peer Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 Electronic Keying . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 More Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Guidelines to Manage I/O Connections . . . . . . . . . . . . . . . . . . . . . . . . 94 Create Tags for I/O Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 Controller Ownership . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 Runtime/Online Addition of Modules. . . . . . . . . . . . . . . . . . . . . . . . . . 98 Online Addition of Module and Connection Types . . . . . . . . . . 99 Design Considerations for Runtime/Online Addition of Modules. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Chapter 10
EtherNet/IP Network Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 Guidelines for EtherNet/IP Networks . . . . . . . . . . . . . . . . . . . . . . . . . 103 ControlNet Network Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 Guidelines for ControlNet Networks . . . . . . . . . . . . . . . . . . . . . . . . . . 104 Guidelines for Unscheduled ControlNet Networks . . . . . . . . . . . . . 105 Compare Scheduled and Unscheduled ControlNet Communication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 DeviceNet Network Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 Guidelines for DeviceNet Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Chapter 11
Cache Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110 Message Buffers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Outgoing Unconnected Buffers. . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 Guidelines for Messages. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 Guidelines to Manage Message Connections. . . . . . . . . . . . . . . . . . . . 112 Guidelines for Block Transfer Messages . . . . . . . . . . . . . . . . . . . . . . . . 113 Map Tags. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
Chapter 12
Guidelines for Tag-Based Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 Access Tag-based Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
Guidelines for Instruction-Based Alarms . . . . . . . . . . . . . . . . . . . . . . . 117 Configure Logix-based Alarm Instructions . . . . . . . . . . . . . . . . . . . . . 118 Automatic Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119

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Optimize an Application for Use with HMI

Chapter 13
Linx-based Software Use of Controller Memory . . . . . . . . . . . . . . . . 121 HMI Implementation Options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 Guidelines for FactoryTalk View Software . . . . . . . . . . . . . . . . . . . . . 122 How a Data Server Communicates with the Controllers. . . . . . . . . 122 Compare RSLinx Classic and FactoryTalk Linx Software . . . . . . . . 124 Guidelines for Linx-based Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124 Guidelines to Configure Controller Tags. . . . . . . . . . . . . . . . . . . . . . . 125
Reference Controller Data from FactoryTalk View Software . 125

Develop Equipment Phases

Chapter 14
Guidelines for Equipment Phases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 Equipment Phase Instructions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128

Manage Firmware

Chapter 15
Guidelines to Manage Controller Firmware . . . . . . . . . . . . . . . . . . . . 129 Compare Firmware Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130 Guidelines for the Firmware Supervisor . . . . . . . . . . . . . . . . . . . . . . . . 131 Access Firmware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133

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Notes:

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Rockwell Automation Publication 1756-RM094K-EN-P - October 2020

Overview Summary of Changes

Preface

Throughout this publication, the term "programming software" refers to: � Studio 5000 Logix Designer� application, version 21 or later � RSLogix 5000� software, version 16 or later

This publication features these controllers, and where applicable, the controllers are known as:

Controller Family 5580 controllers 5380 controllers 5480 controllers 5570 controllers 5370 controllers

Includes these controllers ControlLogix� 5580 and GuardLogix� 5580 controllers CompactLogixTM 5380 and Compact GuardLogix 5380 controllers CompactLogix 5480 Controllers ControlLogix 5570 and GuardLogix 5570 controllers CompactLogix 5370 and Compact GuardLogix 5370 controllers

This manual contains new and updated information as indicated in the following table.

Topic Added ControlLogix 5580 NSE, ControlLogix-XTTM 5580, and ControlLogix 5580 Process controllers. Added CompactLogix 5380 Process controllers Added Pre-defined Tasks in ControlLogix and CompactLogix Process Controllers Updated table: Online Addition of Module and Connection Types Added information on Automatic Diagnostics.

Page Throughout Throughout 33 99 119

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Preface

Additional Resources

These documents contain additional information about the controllers.

Resource
� EtherNet/IPTM Network Devices User Manual, publication ENET-UM006 � ControlNet� Modules in Logix 5000TM Control Systems User Manual, publication CNET-UM001 � DeviceNet� Modules in Logix 5000 Control Systems User Manual, publication DNET-UM004
� System Security Design Guidelines Reference Manual, SECURE-RM001 � Configure System Security Features User Manual, SECURE-UM001 � CIP SecurityTM with Rockwell Automation Products Application Technique, SECURE-AT001
� Replacement Guidelines: Logix 5000 Controllers Reference Manual, publication 1756-RM100 � Logix 5000 Common Procedures Programming Manual, publication 1756-PM001
� ControlLogix 5580 Controllers User Manual, publication 1756-UM543 � ControlLogix System User Manual, publication 1756-UM001 � Motion Configuration and Startup User Manual, publication MOTION-UM001 � Motion Coordinate System User Manual, publication MOTION-UM002
� CompactLogix 5370 Controllers User Manual, publication 1769-UM021 � CompactLogix 5380 and Compact GuardLogix 5380 Controllers User Manual,
publication 5069-UM001 � 1768 CompactLogix System User Manual,publication 1768-UM001 � 1769 CompactLogix System User Manual, publication 1769-UM011 � 1769 Packaged CompactLogix Controllers Quick Start and User Manual,
publication IASIMP-QS010

Description Networks
Provides guidance on how to conduct vulnerability assessments, implement Rockwell Automation products in a secure system, harden the control system, manage user access, and dispose of equipment. Logix 5000TM Controllers ControlLogix Controllers
CompactLogix Controllers

You can view or download publications at http://www.rockwellautomation.com/literature/.

10

Rockwell Automation Publication 1756-RM094K-EN-P - October 2020

1 Chapter

5580 Controller and 5380 Controllers

This chapter highlights these controllers, and where applicable, the controllers are known as:

Controller Family 5580 controllers 5380 controllers

Includes these controllers ControlLogix� 5580 and GuardLogix� 5580 controllers CompactLogixTM 5380 and Compact GuardLogix 5380 controllers

ControlLogix 5580 and GuardLogix 5580 Controllers

Characteristic Controller tasks: � Continuous � Periodic � Event Event tasks User memory
Built-in ports Communication options

ControlLogix 5580 Controllers and GuardLogix 5580 Controllers
� 32 � 1000 programs/task

Consumed tag, EVENT instruction triggers, Module Input Data changes, and motion events

1756-L81E, 1756-L81EK, 1756-L81E-NSE, 1756-L81EXT, 1756-L81EP

3 MB

1756-L82E, 1756-L82EK, 1756-L82E-NSE, 1756-L82EXT

5 MB

1756-L83E, 1756-L83EK, 1756-L83E-NSE, 1756-L83EXT, 1756-L83EP

10 MB

1756-L84E, 1756-L84EK, 1756-L84E-NSE, 1756-L84EXT

20 MB

1756-L85E, 1756-L85EK, 1756-L85E-NSE, 1756-L85EXT, 1756-L85EP

40 MB

1756-L81ES

3 MB +1.5 MB safety

1756-L82ES

5 MB + 2.5 MB safety

1756-L83ES

10 MB +5 MB safety

1756-L84ES

20 MB + 6 MB safety

Single-port Ethernet port, 10 Mbps/100 Mbps/1 Gbps 1-port USB client

� EtherNet/IPTM � ControlNet� � DeviceNet� � Data Highway PlusTM � Remote I/O � SynchLinkTM � USB Client

Rockwell Automation Publication 1756-RM094K-EN-P - October 2020

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Chapter 1 5580 Controller and 5380 Controllers

Characteristic Network nodes
Controller redundancy Integrated motion

ControlLogix 5580 Controllers and GuardLogix 5580 Controllers

Studio 5000 Logix Designer� application, version 30 or later

1756-L81E, 1756-L81EK, 1756-L81E-NSE, 1756-L81EXT, 1756-L81EP, 1756- 100 L81ES

1756-L82E, 1756-L82EK, 1756-L82E-NSE, 1756-L82EXT, 1756-L82ES

175

1756-L83E, 1756-L83EK, 1756-L83E-NSE, 1756-L83EXT, 1756-L83EP, 1756- 250 L83ES, 1756-L84E, 1756-L84EK, 1756-L84E-NSE, 1756-L84EXT, 1756-L84ES

1756-L85E, 1756-L85EK, 1756-L85E-NSE, 1756-L85EXT, 1756-L85EP

300

Fully supported with Studio 5000 Logix Designer Application version 33 later for ControlLogix 5580 controllers. Uses the same firmware revision as standard ControlLogix 5580 controllers, but requires that redundancy is enabled on the Redundancy tab of the Controller Properties dialog.

EtherNet/IP

CompactLogix 5380 and Compact GuardLogix 5380 Controllers

Characteristic Controller tasks: � Continuous � Periodic � Event Event tasks User memory
� Built-in ports � Communication options

CompactLogix 5380 Controllers and Compact GuardLogix 5380 Controllers
� 32 � 1000 programs/task

Consumed tag, EVENT instruction triggers, Module Input Data changes, and motion events

5069-L306ER, 5069-L306ERM

0.6 MB

5069-L310ER, 5069-L310ER-NSE, 5069-L310ERM

1 MB

5069-L320ER, 5069-L320ERM, 5069-L320ERMK,

2 MB

5069-L320ERP

5069-L330ER, 5069-L330ERM, 5069-L330ERMK

3 MB

5069-L340ER, 5069-L340ERM, 5069-L340ERP

4 MB

5069-L350ERM, 5069-L320ERMK

5 MB

5069-L380ERM

8 MB

5069-L3100ERM

10 MB

5069-L306ERS2, 5069-L306ERMS2

0.6 MB + 0.3 MB safety

5069-L310ERS2, 5069-L310ERMS2

1 MB + 0.5 MB safety

5069-L320ERS2, 5069-L320ERMS2, 5069-L320ERS2K, 5069-L320ERMS2K

2 MB + 1 MB safety

5069-L330ERS2, 5069-L330ERMS2, 5069-L330ERS2K, 5069-L330ERMS2K

3 MB + 1.5 MB safety

5069-L340ERS2, 5069-L340ERMS2

4 MB + 2 MB safety

5069-L350ERS2, 5069-L350ERMS2, 5069-L350ERS2K, 5069-L350ERMS2K

5 MB + 2.5 MB safety

5069-L380ERS2, 5069-L380ERMS2

8 MB + 4 MB safety

5069-L3100ERS2, 5069-L3100ERMS2

10 MB + 5 MB safety

� 2 - Ethernet ports, 10 Mbps/100 Mbps/1 Gbps � 1-port USB client

� EtherNet/IP � USB Client

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Rockwell Automation Publication 1756-RM094K-EN-P - October 2020

Characteristic Network nodes
Controller redundancy Integrated motion
Process Controllers
Controller Memory

5580 Controller and 5380 Controllers Chapter 1

CompactLogix 5380 Controllers and Compact GuardLogix 5380 Controllers

Studio 5000 Logix Designer application, version 31or later

5069-L306ER, 5069-L306ERM, 5069-L306ERS2,

16

5069-L306ERMS2

5069-L310ER, 5069-L310ER-NSE, 5069-L310ERM,

24

5069-L310ERS2, 5069-L310ERMS2

5069-L320ER, 5069-L320ERM, 5069-L320ERMK,

40

5069-L320ERP, 5069-L320ERS2, 5069-L320ERMS2

5069-L320ERS2K, 5069-L320ERMS2K

5069-L330ER, 5069-L330ERM, 5069-L330ERMK,

60

5069-L330ERS2, 5069-L330ERMS2

5069-L330ERS2K, 5069-L330ERMS2K

5069-L340ER, 5069-L340ERM, 5069-L340ERP, 5069- 90 L340ERS2, 5069-L340ERMS2

5069-L350ERM, 5069-L350ERMK, 5069-L350ERS2, 120 5069-L350ERMS2
5069-L350ERS2K, 5069-L350ERMS2K

5069-L380ERM, 5069-L380ERS2, 5069-L380ERMS2 150

5069-L3100ERM, 5069-L3100ERS2, 5069-L3100ERMS2 180

Logix Hot Backup - CompactLogix 5380 Controllers only

EtherNet/IP

ControlLogix 5580 and CompactLogix 5380 process controllers are extensions of the Logix 5000TM controller family that focus on plant-wide process control.
The process controllers come configured with a default process tasking model and dedicated PlantPAx� process instructions that are optimized for process applications and that improve design and deployment efforts. The process controllers support release 5.0 of the Rockwell Automation Library of Process Objects.
For more information on the process library, see the Rockwell Automation Library of Process Objects Reference Manual, publication PROCES-RM200.
For more information on process controller application guidelines, see the PlantPAx DCS Configuration and Implementation User Manual, publication PROCES-UM100.
The Logix CPU runs control and motion, communications, and packet processing each on a separate core.
� The Logix Engine executes the user program, the control task, and the motion task.
� The Communications core manages all Class 3 and unconnected communications via the Ethernet, USB, and backplane communication ports. Communications do not interrupt the user task. The System Overhead Time Slice Percentage setting is no longer available and not necessary.
� The Packet Processing Engine moves all Ethernet Class 1 packets to and from the wire, and moves all packets to and from the backplane.

Rockwell Automation Publication 1756-RM094K-EN-P - October 2020

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Chapter 1 5580 Controller and 5380 Controllers

The controller allocates memory as needed to help prevent many runtime errors that are related to free memory. Runtime memory no longer consumes application memory space.

1756 ControlLogix 5580 controllers and CompactLogix 5380 controllers- Memory is in one, contiguous section.

Logic and Data Memory

Logix Engine

Communications Core

Program source code Tag data

Logix CPU Packet Processing Engine

The GuardLogix CPU performs the same functions as the ControlLogix 5580 and CompactLogix 5380 controllers, with these differences:
� The Logix Engine executes the user program, the control task, the motion task, and the safety task.
� The Functional Safety Diagnostic Core runs the safety task with inverted data, and compares the results to the safety task that runs on the Logix Engine.

1756 GuardLogix 5580 controllers and Compact GuardLogix 5380 controllers- Memory is in one, contiguous section.

Logic and Data Memory

Logix Engine

Communications Core

Program source code Tag data

Logix CPU

Functional Safety Diagnostic Core

Packet Processing Engine

Data Types

The controllers support IEC 61131-3 atomic data types. The controllers also support compound data types, such as arrays, predefined structures (such as counters and timers), and user-defined structures).

The Logix CPU reads and manipulates 32-bit data values. The minimum memory allocation for data in a tag is 4 bytes. When you create a standalone tag that stores data that is less than 4 bytes, the controller allocates 4 bytes, but the data only fills the part that it needs.

For more information See Data Structures on page 75.

Data Type Bits

64...32

31

16 15

BOOL

Not allocated

Allocated but not used

SINT

Not allocated

Allocated but not used

INT

Not allocated

Allocated but not used

-32,768...32,767

DINT

Not allocated

REAL

Not allocated

-2,147,483,648...2,147,483,647
-3.40282347E38...-1.17549435E-38 (negative values) 0 1.17549435E-38...3.40282347E38 (positive values)

LINT

-922337203685477580...+9223372036854775807

87

10

0 or 1

-128...+127

14

Rockwell Automation Publication 1756-RM094K-EN-P - October 2020

5580 Controller and 5380 Controllers Chapter 1

Extended Data Types

The 5380 and 5580 controllers support these extended data types:

Data Type
USINT UINT UDINT ULINT LREAL

Bits

64...32

31

16

15

8

7...1

0

Not allocated Allocated but not used

Unsigned 0...255

Not allocated Allocated but not used

Unsigned 0...65,535

Not allocated Unsigned 0...4,294,967,295

Unsigned 0...18,446,744,073,709,551,615

-1.7976931348623157E308...-2.2250738585072014E-308 (negative values) 0.0 2.2250738585072014E-308...1.7976931348623157E308 (positive values)

The compute, compare, and math instructions support these extended data types for 64-bit operations.

Programming Techniques
Programming Technique Subroutines
Add-On Instructions PhaseManagerTM equipment phases

Consideration For Logix Designer application Version 28 and later on 5580 and 5380 controllers: � JSR calls are limited to 40 input parameters and 40 output parameters. � There is a maximum of 25 JSR nesting levels. For 5580 controllers 5380 controllers, you can nest Add-On Instructions up to 25 levels. The PhaseManager option is support on 5580 and 5380 controllers as of firmware revision 32.
For more information See Modular Programming Techniques on page 45.

Data Alignment Rules
The 5580, 5380, and all 64-bit controllers have these data alignment rules on UDTs:
� 8-byte (64-bit) data types (LINT, ULINT, and LREAL) are placed on 8-byte address boundaries in RAM. The Studio 5000 Logix Designer application manages this requirement automatically.
� UDTs that have no 8-byte elements retain the existing 4-byte memory allocation rules.
� UDTs that contain LINTs are considered to be 8-byte data types and their size is a multiple of 8 bytes.
� 8-byte data types (LINTs or embedded UDTs) within a data structure are aligned on an 8-byte boundary.

Rockwell Automation Publication 1756-RM094K-EN-P - October 2020

15

Chapter 1 5580 Controller and 5380 Controllers

Produced and Consumed Data

The controller supports: � Total number of produced tags 255 � Maximum number of multicast produce tags out of the Ethernet port  32 � Maximum number of consumed tags  255
For more information See Produced and Consumed Data on page 71.

Connections

The controller supports: � Dedicated Class 1 (I/O, Produce and Consume, implicit, and so on) connection pool to support controller node count � Dedicated Class 3 (HMI, message instructions, explicit, and so on) connection pool to support up to 512 connections � This pool is split; 256 incoming and 256 outgoing connections � 256 cached buffers � 320 unconnected buffers for establishing connections � This value is fixed and cannot be increased with a CIPTM Generic message instruction.

16

Rockwell Automation Publication 1756-RM094K-EN-P - October 2020

2 Chapter

5480 Controller

CompactLogix 5480 Controller

Characteristic Controller tasks: � Continuous � Periodic � Event Event tasks User memory
Built-in ports

CompactLogixTM 5480 Controller
� 32 tasks � 1000 programs/task � All event triggers

Consumed tag, EVENT instruction triggers, Module Input Data changes, and motion events

Windows 10 (commercial operating system on controller)

� RAM: 6 GB � SSD: 64 GB

Logix control engine

5069-L430ERMW

3 MB

5069-L450ERMW

5 MB

5069-L4100ERMW

10 MB

5069-L4200ERMW

20 MB

Logix control engine use: � 3 - Ethernet, 10 Mpbs/100 Mbps/1 Gbps � 1 - USB client
IMPORTANT: Consider the following � When the controller operates in Dual-IP mode, each Ethernet port requires a unique IP address. � When the controller operates in Linear/DLR mode, the controller uses only one IP address.

Communication options Network nodes
Controller redundancy Integrated motion

Windows 10 use: � 1 - Ethernet, 10 Mbps/100 Mbps/1 Gbps � 2 - USB 3.0 ports � 1 - DisplayPort

� Dual-port EtherNet/IPTM � USB Client

Studio 5000 Logix Designer� application, version 32.00.00 or later

5069-L430ERMW

60

5069-L450ERMW

120

5069-L4100ERMW

180

5069-L4200ERMW

250

5069-L46ERMW

250

None

Total axis count

512 (Any combination of physical, virtual, or consumed axes)

Virtual axis, max

512

Position-loop axis, max

150

Axes/ms, max

100

Rockwell Automation Publication 1756-RM094K-EN-P - October 2020

17

Chapter 2 5480 Controller
Controller Memory

The Logix CPU runs control and motion, communications, and packet processing each on a separate core.
� The Logix Engine executes the user program, the control task, and the motion task.
� The Communications core manages all Class 3 and unconnected communications via the Ethernet, USB, and backplane communication ports. Communications do not interrupt the user task, and you do not need to adjust the System Overhead Time Slice Percentage.
� The Packet Processing Engine moves all Ethernet Class 1 packets to and from the wire, and moves all packets to and from the backplane.

The controller allocates memory as needed to help prevent many runtime errors that are related to free memory. Runtime memory no longer consumes application memory space.

1756 CompactLogix 5480 controllers- Memory is in one, contiguous section.

Logic and Data Memory

Logix Engine

Communications Core

Program source code Tag data

Logix CPU Packet Processing Engine

Data Types

The controllers support IEC 61131-3 atomic data types. The controllers also support compound data types, such as arrays, predefined structures (such as counters and timers, and user-defined structures.)

The Logix CPU reads and manipulates 32-bit data values. The minimum memory allocation for data in a tag is 4 bytes. When you create a standalone tag that stores data that is less than 4 bytes, the controller allocates 4 bytes, but the data only fills the part that it needs.

For more information See Data Structures on page 75.

Data Type Bits

64...32

31

16 15

BOOL

Not allocated

Allocated but not used

SINT

Not allocated

Allocated but not used

INT

Not allocated

Allocated but not used

-32,768...32,767

DINT

Not allocated

REAL

Not allocated

-2,147,483,648...2,147,483,647
-3.40282347E38...-1.17549435E-38 (negative values) 0 1.17549435E-38...3.40282347E38 (positive values)

LINT

-9223372036854775808...+9223372036854775807

87

10

0 or 1

-128...+127

18

Rockwell Automation Publication 1756-RM094K-EN-P - October 2020

5480 Controller Chapter 2

Extended Data Types

The 5480 controller supports these extended data types:

Data Type
USINT UINT UDINT ULINT LREAL

Bits

64...32

31

16

15

8

7...1

0

Not allocated Allocated but not used

Unsigned 0...255

Not allocated Allocated but not used

Unsigned 0...65,535

Not allocated Unsigned 0...4,294,967,295

Unsigned 0...18,446,744,073,709,551,615

-1.7976931348623157E308...-2.2250738585072014E-308 (negative values) 0.0 2.2250738585072014E-308...1.7976931348623157E308 (positive values)

The compute, compare, and math instructions support these extended data types for 64-bit operations.

Programming Techniques
Programming Technique Subroutines
Add-On Instructions PhaseManagerTM equipment phases

Consideration
For Logix Designer application Version 32.00.00 and later: � JSR calls are limited to 40 input parameters and 40 output parameters. � There is a maximum of 25 JSR nesting levels.
You can nest Add-On Instructions up to 25 levels.
The PhaseManager option is supported on 5480 controllers as of firmware revision 32.

For more information See Modular Programming Techniques on page 45.

Data Alignment Rules
The 5480 controllers have these data alignment rules on UDTs: � 8-byte (64-bit) data types (LINT, ULINT, and LREAL) are placed on 8byte address boundaries in RAM. The Studio 5000 Logix Designer application manages this requirement automatically. � UDTs that have no 8-byte elements retain the existing 4-byte memory allocation rules. � UDTs that contain LINTs are considered to be 8-byte data types and their size is a multiple of 8 bytes. � 8-byte data types (LINTs or embedded UDTs) within a data structure are aligned on an 8-byte boundary.

Rockwell Automation Publication 1756-RM094K-EN-P - October 2020

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Chapter 2 5480 Controller

Produced and Consumed Data

The controller supports: � Total number of produced tags 255 � Maximum number of multicast produce tags out of the Ethernet port  32 � Maximum number of consumed tags  255
For more information See Produced and Consumed Data on page 71.

Connections

The controller supports: � Dedicated Class 1 (I/O, Produce and Consume, implicit, and so on) connection pool to support controller node count � Dedicated Class 3 (HMI, message instructions, explicit, and so on) connection pool to support up to 512 connections � This pool is split; 256 incoming and 256 outgoing connections � 256 cached buffers � 320 unconnected buffers for establishing connections � This value is fixed and cannot be increased with a CIPTM Generic message instruction.

20

Rockwell Automation Publication 1756-RM094K-EN-P - October 2020

3 Chapter
5570 Controllers and 5370 Controllers

This chapter highlights these controllers, and where applicable, the controllers are known as:

Controller Family 5570 controllers 5370 controllers

Includes these controllers ControlLogix� 5570 and GuardLogix� 5570 controllers CompactLogixTM 5370 and Compact GuardLogix 5370 controllers

ControlLogix 5570 and GuardLogix 5570 Controllers

Characteristic

ControlLogix 5570 Controllers GuardLogix 5570 Controllers ArmorTM ControlLogix 5570 Controllers ArmorTM GuardLogix� 5570 Controllers

Controller tasks: � Continuous � Periodic � Event

� 32 � 1000 programs/task

Event tasks

Consumed tag, EVENT instruction triggers, Module Input Data changes, and motion events

User memory

1756-L71, 1756-L71EROM

2 MB

1756-L72, 1756-L72EROM

4 MB

1756-L73, 1756-L73XT, 1756-L73EROM

8 MB

1756-L74

16 MB

1756-L75

32 MB

1756-L71S, 1756-L71EROMS

2 MB +1 MB safety

1756-L72S, 1756-L72EROMS

4 MB + 2 MB safety

1756-L73S, 1756-L73EROMS

8 MB + 4 MB safety

Built-in ports

1756-L71, 1756-L72, 1756-L73, 1756-L73XT, 1756-L74, 1756-L75, 1756-L71S, 1756-L72S, 1756-L73S

1-port USB Client

1756-L71EROM, 1756-L71EROMS, 1756-L72EROM, 1756-L72EROMS, 1756-L73EROM, 1756-L73EROMS

� 1-port USB client � Dual-port EtherNet/IPTM, 10 Mpbs/100 Mbps

Communication options

� EtherNet/IP � ControlNet� � DeviceNet� � Data Highway PlusTM � Remote I/O � SynchLinkTM � USB Client

Controller connections

500 connections

Controller redundancy

1756-L71, 1756-L72, 1756-L73, 1756-L73XT, 1756-L74, and 1756-L75 controllers only. Full support with a separate redundancy firmware revision.

Integrated motion

EtherNet/IP

Rockwell Automation Publication 1756-RM094K-EN-P - October 2020

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Chapter 3 5570 Controllers and 5370 Controllers

CompactLogix 5370 and Compact GuardLogix 5370 Controllers

Characteristic Controller tasks: � Continuous � Periodic � Event Event tasks User memory
Built-in ports Communication options
Controller connections Network nodes

CompactLogix 5370 Controllers and Compact GuardLogix 5370 Controllers Armor CompactLogix 5370 Controllers and Armor Compact GuardLogix 5370 Controllers
� 32 � 1000 programs/task

Consumed tag, EVENT instruction triggers, and motion events

1769-L16ER-BB1B

384 KB

1769-L18ER-BB1B, 1769-L18ERM-BB1B, 1769-L18ERM-BB1BK 512 KB

1769-L24ER-QB1B, 1769-L24ER-QBFC1B, 1769-L24ER-QBFC1BK

750 KB

1769-L19ER-BB1B, 1769-L19ER-BB1BK,

1 MB

1769-L27ERM-QBFC1B, 1769-L30ER, 1769-L30ERK,

1769-L30ER-NSE, 1769-L30ERM, 1769-L30ERMK

1769-L33ER, 1769-L33ERK, 1769-L33ERM, 1769-L33ERMK, 2 MB 1769-L33ERMO

1769-L36ERM, 1769-L36ERMO

3 MB

1769-L37ERM, 1769-L37ERMK, 1769-L37ERMO

4 MB

1769-L38ERM, 1769-L38ERMK, 1769-L38ERMO

5 MB

1769-L30ERMS

1 MB + 0.5 MB safety

1769-L33ERMS, 1769-L33ERMSK, 1769-L33ERMOS

2 MB + 1 MB safety

1769-L36ERMS, 1769-L36ERMOS

3 MB + 1.5 MB safety

1769-L37ERMS, 1769-L37ERMSK, 1769-L37ERMOS

4 MB + 1.5 MB safety

1769-L38ERMS, 1769-L38ERMSK, 1769-L38ERMOS

5 MB + 1.5 MB safety

Dual-port EtherNet/IP 1-port USB Client

EtherNet/IP Embedded switch Single IP address DeviceNet USB Client

256 connections

1769-L16ER-BB1B

4

1769-L18ER-BB1B, 1769-L18ERM-BB1B,

8

1769-L18ERM-BB1BK, 1769-L19ER-BB1B, 1769-L19ER-BB1BK

1769-L27ERM-QBFC1B, 1769-L30ER,

16

1769-L30ERK,1769-L30ER-NSE, 1769-L30ERM,

1769-L30ERMK, 1769-L30ERMS

1769-L33ER, 1769-L33ERK, 1769-L33ERM, 1769-L33ERMK, 32 1769-L33ERMS, 1769-L33ERMSK, 1769-L33ERMO, 1769-L33ERMOS

1769-L36ERM, 1769-L36ERMS, 1769-L36ERMO,

48

1769-L36ERMOS

1769-L37ERM, 1769-L37ERMS, 1769-L37ERMO,

64

1769-L37ERMOS, 1769-L37ERMK, 1769-L37ERMSK

1769-L38ERM, 1769-L38ERMS, 1769-L38ERMO,

80

1769-L38ERMOS, 1769-L38ERMK, 1769-L38ERMSK

22

Rockwell Automation Publication 1756-RM094K-EN-P - October 2020

Characteristic
Controller redundancy
Integrated motion Conformal coating

5570 Controllers and 5370 Controllers Chapter 3
CompactLogix 5370 Controllers and Compact GuardLogix 5370 Controllers Armor CompactLogix 5370 Controllers and Armor Compact GuardLogix 5370 Controllers Back up via DeviceNet - CompactLogix 5370 L3 Controllers and Compact GuardLogix 5370 L3 controllers only Logix Hot Backup - CompactLogix 5370 L3 Controllers only EtherNet/IP 1769-L30ERK,1769-L30ERMK, 1769-L33ERK, 1769-L33ERMK, 1769-L33ERMSK, 1769-L37ERMK, 1769-L37ERMSK, 1769-L38ERMK, 1769-L38ERMSK

Controller Memory

The Logix CPU executes application code and messages. The backplane CPU transfers I/O memory and other module data on the backplane. This CPU operates independently from the Logix CPU, so it sends and receives I/O information asynchronous to program execution.
TIP CPU usage is based on the number of devices in the I/O tree. About 6% of the CPU is used for every 100 devices in the I/O tree.

1756 ControlLogix 5570 controllers - Memory is separated into isolated sections. Project Documentation Memory Logic and Data Memory

Comment descriptions Alarm log Extended tag properties

Program source code

Logix

Tag data

CPU

HMI tag group lists

I/O Memory I/O data I/O force tables Message buffers Produced/consumed tags

Backplane CPU

CompactLogix 5370 and Compact GuardLogix 5370 Controllers

The Logix CPU executes application code and messages.

Controller CompactLogix 5370

I/O Task Priority 6

Communication Task Priority 12

CompactLogix 5370 controllers - Memory is separated into isolated segments.

Project Documentation Memory

Logic and Data Memory

Comment descriptions Alarm log

Program source code

Logix

Tag data

CPU

Extended tag properties

HMI tag group lists

I/O Memory I/O data I/O force tables Message buffers Produced/consumed tags

Rockwell Automation Publication 1756-RM094K-EN-P - October 2020

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Chapter 3 5570 Controllers and 5370 Controllers

Controller Connections

The controller uses a connection to establish a communication link between two devices.

IMPORTANT The topics in this section apply only to ControlLogix 5570 and earlier controllers, and CompactLogix 5370 and earlier controllers operation

Connections can be made to the following: � Controller to local I/O modules or local communication modules � Controller to remote I/O or remote communication modules � Controller to remote I/O (rack-optimized) modules � Produced and consumed tags � Messages � Access to programming software � Linx-based software access for HMI or other software applications

The controllers have different communication limits.

Communication Attribute 1756-L7x ControlLogix

1756-L6x ControlLogix 1769 CompactLogix CompactLogix 5370 1768 CompactLogix

Connections

500

250

100

256

250

Cached messages

32 for messages and block transfers combined

Unconnected receive buffers 3

Unconnected transmit buffers Default 20 (can be increased to 40) Default 10 (can be increased to 40)

The limit of connections can ultimately reside in the communication module you use for the connection. If a message path routes through a communication module, the connection that is related to the message also counts toward the connection limit of that communication module.

Controller ControlLogix

Communication Device 1756-CN2R, 1756-CN2RXT

Supported Connections
100 CIPTM connections (any combination of scheduled and message connections)

1756-CN2/B

128 CIP connections

1756-CNB,1756 -CNBR

64 CIP connections depending on RPI, recommend that you use only 48 connections (any combination of scheduled and message connections)

1756-EN2F, 1756-EN2T, 1756-EN2TR, 256 CIP connections 1756-EN2TP, 1756-EN2TXT, 1756-EN3TR 128 TCP/IP connections

1756-EN4TR

CIP connected messages: � 1000 I/O � 528(1)
512 TCP/IP connections

1756-ENBT 1756-EWEB

128 CIP connections 64 TCP/IP connections

CompactLogix 5370 Built-in Ethernet ports

See the CompactLogix 5370 Controllers User Manual, publication 1769-UM021, for information on how to count EtherNet/IP nodes on the I/O Configuration section of the programming software.

(1) There are 1000 explicit connections and 528 implicit connections.

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Connection Type Local I/O module (always a direct connection) SERCOS Motion module ControlNet communication module EtherNet/IP communication module DeviceNet communication module DH+/Remote I/O communication module DH-485 communication module Programming software access to controller Total

5570 Controllers and 5370 Controllers Chapter 3

Determine Total Connection Requirements

The total connections for a controller include both local and remote connections. Counting local connections is not an issue for CompactLogix controllers. They support the maximum number of modules that are permitted in their systems.

When designing your CompactLogix 5370 controllers, you must consider these resources:
� EtherNet/IP network nodes � Controller connections

For more information, see the CompactLogix 5370 Controllers User Manual, publication 1769-UM021.

The ControlLogix controllers support more communication modules than the other controllers, so you must tally local connections to make sure that you stay within the connection limit.

Use this table to tally local connections.

Device Quantity

x Connections per Module x1 x3 x0 x0 x2 x1 x1 x1

= Total Connections = = = = = = = =

IMPORTANT A redundant system uses eight connections in the controller.

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Chapter 3 5570 Controllers and 5370 Controllers

The communication modules that you select determine how many remote connections are available. Use this table to tally remote connections.

Connection Type
Remote ControlNet communication module Configured as a direct (none) connection Configured as a rack-optimized connection
Remote EtherNet/IP communication module Configured as a direct (none) connection Configured as a rack-optimized connection
Remote device over a DeviceNet network (accounted for in rack-optimized connection for local DeviceNet module)
Safety device on a DeviceNet or EtherNet/IP network
Other remote communication adapter
Distributed I/O module (individually configured for a direct connection)
Produced tag and first consumer Each additional consumer
Consumed tag
Connected message (CIP Data Table read/write and DH+TM)
Block transfer message
Linx-based software access for HMI or other software applications
FactoryTalk� Linx software for HMI or other software applications
Total

Device Quantity

x Connections per Module
x 0 or 1
x 0 or 1
x0

= Total Connections =
=
=

x2

=

x1

=

x1

=

x2

=

1

x1

=

x1

=

x1

=

x4

=

x5

=

System Overhead Percentage The system overhead timeslice specifies the percentage of continuous task
execution time that is devoted to communication and background redundancy functions.
� Message communication is any communication that you do not configure through the I/O configuration folder of the project, such as MSG instructions.
� Message communication occurs only when a periodic or event task is not running. If you use multiple tasks, make sure that their scan times and execution intervals leave enough time for message communication.
� System overhead interrupts only the continuous task. � The controller performs message communication for up to 1 ms at a
time and then resumes the continuous task. � Adjust the update rates of the tasks as needed to get the best trade-off
between executing your logic and servicing message communication.
System overhead functions include the following: � Communicating with HMI devices and programming software � Sending and responding to messages � Alarm management processing � Redundancy qualification

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Continuous Task 10% CPU Overhead
Continuous Task 25% CPU Overhead
Periodic Task CPU Overhead

5570 Controllers and 5370 Controllers Chapter 3
The controller performs system overhead functions for up to 1 ms at a time. If the controller completes the overhead functions in less than 1 ms, it resumes the continuous task. The following chart compares a continuous and periodic task.
Continuous Task Restarts

Example
Continuous task 10% CPU overhead
Continuous task 25% CPU overhead
Periodic task

Periodic Task Restarts

Description
In the top example, the system overhead timeslice is set to 10%. Given 40 ms of code to execute, the continuous task completes the execution in 44 ms. During a 60 ms period, the controller is able to spend 5 ms on communication processing.
By increasing the system overhead timeslice to 25%, the controller completes the continuous task scan in 57 ms. The controller spends 15 ms of a 60 ms time span on communication processing.
Placing the same code in a periodic task yields even more time for communication processing. The bottom example assumes that the code is in a 60 ms periodic task. The code executes to completion and then goes dormant until the 60 ms, time-based trigger occurs. While the task is dormant, all CPU bandwidth can focus on communication. Because the code takes only 40 ms to execute, the controller can spend 20 ms on communication processing. Depending on the amount of communication to process during this 20 ms window, it can be delayed as it waits for other modules in the system to process the data that was communicated.

The CPU timeslices between the continuous task and system overhead. Each task switch between user task and system overhead takes additional CPU time to load and restore task information. You can calculate the continuous task interval as:
ContinuousTime=(100/SystemOverheadTimeSlice%) - 1
The programming software forces at least 1 ms of execution time for the continuous task, regardless of the system overhead timeslice. This more efficiently uses system resources because letting shorter execution times of the continuous task exist means switching tasks more frequently.

System Overhead Timeslice % Communication Execution (ms)

10

1

20

1

33

1

50

1

66

2

80

4

90

9

Continuous Task Execution (ms) 9 4 2 1 1 1 1

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Chapter 3 5570 Controllers and 5370 Controllers
Manage the System Overhead Timeslice Percentage
As the system overhead timeslice percentage increases, time that is allocated to executing the continuous task decreases. If there is no communication for the controller to manage, the controller uses the communication time to execute the continuous task.
IMPORTANT System Overhead Time Slice does not apply to ControlLogix 5580 or CompactLogix 5380 controllers.

Consideration Continuous task always has at least 1 ms execution time
Impact on communication and scan time

Description
The programming software forces the continuous task to have at least 1 ms of execution time, regardless of the setting for the system overhead timeslice. This results in more efficient controller use because excessive swapping between tasks uses valuable CPU resources.
Increasing the system overhead timeslice percentage decreases execution time for the continuous task while it increases communication performance. Increasing the system overhead timeslice percentage also increases the amount of time it takes to execute a continuous task - increasing overall scan time.

Tags Per Second

Program Scan Time

Program Scan Time in Milliseconds Tags per Second

Unused portion of system overhead timeslice System overhead

System Timeslice %
You can configure any unused portion of the system overhead timeslice to: � Run the continuous task, which results in faster execution of application code and increases the variability of the
program scan. � Process communication, which results in more predictable and deterministic scan time for the continuous task.
(This is for development and testing of an application to simulate communication.)
System overhead is the time that the controller spends on message communication and background tasks. � Message communication is any communication that you do not configure through the I/O configuration folder of
the project, such as MSG instructions. � Message communication occurs only when a periodic or event task is not running. If you use multiple tasks, make
sure that their scan times and execution intervals leave enough time for message communication. � System overhead interrupts only the continuous task. � The system overhead timeslice specifies the percentage of time (excluding the time for periodic or event tasks)
that the controller devotes to message communication. � System overhead timeslice does not apply to ControlLogix 5580 and CompactLogix 5380 controllers. � The controller performs message communication for up to 1 ms at a time and then resumes the continuous task. � Adjust the update rates of the tasks as needed to get the best trade-off between executing your logic and servicing
message communication.

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5570 Controllers and 5370 Controllers Chapter 3
Individual applications can differ, but the overall impact on communication and scan time remains the same. The data is based on a ControlLogix5555 controller running a continuous task with 5000 tags (no arrays or user-defined structures).

The 5370 controllers use a dedicated periodic task to process I/O data. This I/O task:
� Operates at priority 6. � Higher-priority tasks take precedence over the I/O task and can affect
processing. � Executes at the fastest RPI you have scheduled for the system. � Executes for as long as it takes to scan the configured I/O modules.

The controllers support IEC 61131-3 atomic data types. The controllers also support compound data types, such as arrays, predefined structures (such as counters and timers), and user-defined structures.

The Logix CPU reads and manipulates 32-bit data values. The minimum memory allocation for data in a tag is 4 bytes. When you create a standalone tag that stores data that is less than 4 bytes, the controller allocates 4 bytes, but the data only fills the part that it needs.

For more information See Data Structures on page 75.

Data Type Bits

64...32

31

16

15

8

7

10

BOOL

Not allocated

Allocated but not used

0 or 1

SINT

Not allocated

Allocated but not used

-128...+127

INT

Not allocated

Allocated but not used

-32,768...32,767

DINT

Not allocated

REAL

Not allocated

-2,147,483,648...2,147,483,647
-3.40282347E38...-1.17549435E-38 (negative values) 0 1.17549435E-38...3.40282347E38 (positive values)

LINT

Valid Date/Time range is from 1/1/1970 12:00:00 AM coordinated universal time (UTC) to 1/1/3000 12:00:00 AM UTC

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Programming Techniques
Programming Technique Subroutines
Add-On Instructions

Consideration
For Studio 5000 Logix Designer� Version 28 and later on 5570 and 5370 controllers: � JSR calls are limited to 40 input parameters and 40 output parameters. � There is no limit on nesting JSR instructions. However, it is possible that too many nesting levels can cause the
controller to run out of memory and fault.
For 5570 controllers or earlier, and 5370 controllers or earlier, there is no limit on nesting Add-On Instructions. However, it is possible that too many nesting levels can cause the controller to run out of memory and fault.
For more information See Modular Programming Techniques on page 45.

Produced and Consumed Data

The controller supports: � Total number of produced tags  127 � Maximum number of multicast produce tags out of the CompactLogix Ethernet port  32 � Maximum number of consumed tags  250 (or controller maximum)
For more information See Produced and Consumed Data on page 71

Messages

The controller supports: � As many outgoing, unconnected buffers as fit in controller memory.
Each buffer uses approximately 1.2 KB of I/O memory.
You can use a CIP Generic message instruction to increase the number of unconnected buffers. See the Logix 5000TM Controllers Messages Programming Manual, publication 1756-PM012. � Three incoming unconnected buffers � 32 cached buffers, as of firmware revision 12 and later.

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4 Chapter

The controller operating system is a pre-emptive multitasking system that is IEC 61131-3 compliant.

Tasks to configure controller execution

A task provides scheduling and priority information for a set of one or more programs. You can configure tasks as either continuous, periodic, or event.

Programs to group data and logic

A task contains programs, each with its own routines and program-scoped tags. Once a task is triggered (activated), the programs that are assigned to the task execute in the order in which they are listed in the Controller Organizer.
Programs are useful for projects that multiple programmers develop. During development, the code in one program that uses program-scoped tags can be duplicated in a second program to minimize the possibility of tag names colliding.
Tasks can contain programs and equipment phases.

Routines to encapsulate executable code that Routines contain the executable code. Each program has a main routine that is the first routine to execute within a program. Use is written in one programming language logic, such as the Jump to Subroutine (JSR) instruction, to call other routines. You can also specify an optional program fault
routine.

Decide When to Use Tasks, Programs, and Routines

Use these considerations to determine when to use a task, program, or routine.

Comparison Quantity available
Function Use
Considerations

Task

Program and Equipment Phase

Routine

Varies by controller (4, 6, 8, or 32)

32 program and equipment phases (combined) per task
100 for ControlLogix� controllers with V23 and earlier
1000 programs/task for ControlLogix controllers with V24 and later

Unlimited number of routines per program

Determines how and when code is executed Organizes groups of routines that share a common data area and function.

Contains executable code (relay ladder, function block diagram, sequential function chart, or structured text)

� Most code is expected to reside in a continuous task
� Use a periodic task for slower processes or when time-based operation is critical
� Use an event task for operations that require synchronization to a specific event

� Put major equipment pieces or plant cells into isolated programs
� Use programs to isolate different programmers or create reusable code
� Configurable execution order within a task � Isolate individual batch phases or discrete
machine operations

� Isolate machine or cell functions in a routine � Use the appropriate language for the process � Modularize code into subroutines that can be called
multiple times

� A high number of tasks can be difficult to debug
� Can disable output processing on some tasks to improve performance
� Tasks can be inhibited to help prevent execution
� Do not configure multiple tasks at the same priority

� Data spanning multiple programs must be controller-scoped or a program parameter.
� Listed in the Controller Organizer in the order of execution

� Subroutines with multiple calls can be difficult to debug
� Data can be referenced from program-scoped and controller-scoped areas
� Calling many routines impacts scan time � Listed in the Controller Organizer as Main, Fault,
and then alphabetically

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Specify Task Priorities

Each task in the controller has a priority level. A higher priority task (such as 1) interrupts any lower priority task (such as 15). The continuous task has the lowest priority; periodic or event tasks always interrupt continuous tasks.

Priority Highest
Lowest

The controller has these types of tasks.

User Task -- -- -- -- -- Priority 1 Event/Periodic Priority 2 Event/Periodic Priority 3 Event/Periodic Priority 4 Event/Periodic Priority 5 Event/Periodic Priority 6 Event/Periodic
Priority 7 Event/Periodic Priority 8 Event/Periodic Priority 9 Event/Periodic Priority 10 Event/Periodic Priority 11 Event/Periodic Priority 12 Event/Periodic
Priority 13 Event/Periodic Priority 14 Event/Periodic Priority 15 Event/Periodic Continuous

Description CPU overhead - general CPU operations Motion planner - executed at coarse update rate Safety task - safety logic Redundancy task - communication in redundant systems Trend data collection - high-speed collection of trend data values User defined User defined User defined User defined User defined User defined 1769 CompactLogixTM controllers process I/O as a periodic task based on the chassis RPI setting User defined User defined User defined User defined User defined User defined CompactLogix communication and scheduled connection maintenance User defined User defined User defined Lowest priority task. Interrupted by all other tasks including system overhead timeslice (if applicable.)

If a periodic or event task is executing when another is triggered, and both tasks are at the same priority level, the tasks execute in 1 ms increments until one of the tasks completes execution.

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Manage User Tasks

You can configure these user tasks.

If you want logic to execute All of the time

Use this task Continuous task

� At a constant period (such as every 100 ms)

Periodic task

� Multiple times within the scan of your other logic

Immediately when an event occurs

Event task

Description
The continuous task runs in the background. Any CPU time that is not allocated to other operations or tasks is used to execute the continuous task. � The continuous task runs all of the time. When the continuous task completes a full scan, it
restarts immediately. � A project does not require a continuous task. If used, there can be only one continuous task.
A periodic task performs a function at a specific time interval. Whenever the time for the periodic task expires, the periodic task: � Interrupts any lower priority tasks. � Executes one time. � Returns control to where the previous task left off.
An event task performs a function only when a specific event (trigger) occurs. Whenever the trigger for the event task occurs, the event task: � Interrupts any lower priority tasks. � Executes one time. � Returns control to where the previous task left off.

The user tasks that you create appear in the Tasks folder of the controller. The predefined system tasks do not appear in the Tasks folder and they do not count toward the task limit of the controller.

Pre-defined Tasks in ControlLogix and CompactLogix Process Controllers
PlantPAx system release 5.0 adds process controllers to the Logix 5000 family of controllers. The process controllers offer additional capabilities that are targeted for DCS applications.
The Task folder contains a project structure that consists of four pre-defined periodic tasks:
� Fast (100 ms) � For control fast loops, such as liquid flow or pressure with related transmitters and pump drives
� Normal (250 ms) � For discrete control, such as motors, pumps, and valves
� Slow (500 ms) � For level, temperature, analysis loops, phases, and batch sequencing
� System (1000 ms) � For slow change temperature control and general controller operations, such as messaging or status

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Considerations that Affect Task Execution

Consideration Motion planner
Output processing Too many tasks

Description
The motion planner interrupts all other tasks, regardless of their priority. � The number of axes and coarse update period for the motion group affect how long and how often the motion planner executes. � If the motion planner is executing when a task is triggered, the task waits until the motion planner is done. � If the coarse update period occurs while a task is executing, the task pauses to let the motion planner execute.
At the end of a task, the controller performs output processing for the output modules in your system. This processing depends on the number of output connections that are configured in the I/O tree.
If you have too many tasks, then the following can occur: � Continuous task can take too long to complete. � Other tasks can experience overlaps. If a task is interrupted too frequently or too long, it must be triggered again to complete its
execution. � Controller communication can be slower. � If your application is designed for data collection, try to avoid multiple tasks.

Table 1 - Example Task Execution

This example depicts the execution of a project with these tasks.

Task Motion planner Event task 1 Periodic task 1 Continuous task

Priority -- 1 2 --

Period 8 ms (course update rate) -- 12 ms --

Execution Time 1 ms 1 ms 2 ms 20 ms

Duration 1 ms
12 ms 24 ms
48 ms

Legend:

Task executes.

Task is interrupted (suspended).

Motion Planner
Event Task 1
Periodic Task 1
Continuous Task

5

10

15

20

25

30

35

40

45

50

1

2

3

4

Description
1 Initially, the controller executes the motion planner and the I/O task (if one exists).
2 The period for periodic task 1 expires (12 ms), so the task interrupts the continuous task.
3 The triggers occur for event task 1. Event task 1 waits until the motion planner is done. Lower priority tasks experience longer delays.
4 The continuous task automatically restarts.

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Configure a Continuous Task

When you create a project in the programming software, the Main Task is configured as a continuous task.
� A controller supports one continuous task, but a continuous task is not required.
� You can configure the task to update output modules at the end of the continuous task.
� You can change the continuous task to either a periodic or event task.

Configure a Periodic Task

A periodic task executes automatically based on a preconfigured interval. You can configure whether the task updates output modules at the end of the periodic task. After the task executes, it does not execute again until the configured time interval has elapsed.

Configure an Event Task

An event task executes automatically based on a trigger event occurring, or if a trigger event does not occur in a specific time interval. You configure whether the task updates output modules at the end of the task. After the task executes, it does not execute again until the event occurs again. Each event task requires a specific trigger.

Trigger Module Input Data State Change
Consumed Tag Axis Registration 1 or 2 Axis Watch Motion Group Execution EVENT Instruction

Description
A remote input module (digital or analog) triggers an event task that is based on the change of state (COS) configuration for the module. Enable COS for only one point on the module. If you enable COS for multiple points, a task overlap of the event task can occur. � The ControlLogix sequence of events modules (1756-IB16ISOE, 1756-IH16ISOE) use the Enable Coordinated System Time (CST) Capture
feature instead of COS. � The embedded input points on the 1769-L16ER-BB1B, 1769-L18ER-BB1B, 1769-L18ERM-BB1B, 1769-L18ERM-BB1B, and
1769-L19ER-BB1BKmodules can be configured to trigger an event task when a COS occurs.
Only one consumed tag can trigger a specific event task. Use an Immediate Output (IOT) instruction in the producing controller to signal the production of new data.
A registration input triggers the event task.
A watch position triggers the event task.
The coarse update period for the motion group triggers the execution of both the motion planner and the event task. Because the motion planner interrupts all other tasks, it executes first.
Multiple EVENT instructions can trigger the same task.

For more information on event tasks, see:
� Logix 5000TM Controllers Common Procedures Programming Manual, publication 1756-PM001
� Using Event Tasks with Logix 5000 Controllers, publication LOGIX-WP003

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Guidelines to Configure an Event Task

Guideline
Place the I/O module being used to trigger an event in the same chassis as the controller.
Limit events on digital inputs to one input bit on a module.
Set the priority of the event task as the highest priority on the controller.
Limit the number of event tasks.

Description Placing the I/O module in a remote chassis adds more network communication and processing to the response time.
All inputs on a module trigger one event, so if you use multiple bits you increase the chance of a task overlap. Configure the module to detect change of state on the trigger input and turn off the other bits. If the priority of the event task is lower than a periodic task, the event task has to wait for the periodic task to complete execution. Increasing the number of event tasks reduces the available CPU bandwidth and increases the chances of task overlap.

Additional Considerations for Periodic and Event Tasks

Consideration Amount of code in the event task Task priority CPS and UID instructions Motion planner Trends Output processing

Description Each logic element (for example, rung, instruction, or structured text construct) adds to scan time. If the event task is not the highest priority task, a higher priority task can delay or interrupt the execution of the event task. If one of these instructions is active, the event task cannot interrupt the currently executing task. (The task with the CPS or UID.) The motion planner takes precedence over event or periodic tasks Trend data collection takes precedence over event or periodic tasks. You can disable output processing at the end of a task to reduce the amount of task processing time. The Controller Organizer displays whether outputs processing is disabled.

Access the Module Object

The MODULE object provides status information about a module. To select a particular module object, set the Object Name operand of the GSV/SSV instruction to the module name. The specified module must be present in the I/O Configuration section of the controller organizer and must have a device name.
With the Studio 5000 Logix Designer� application, version 24.00.00 and later, you can access the MODULE object directly from an Add-On Instruction. Previously, you could access the MODULE object data, but not from within an Add-On Instruction.
You must create a Module Reference parameter when you define the Add-On Instruction to access the MODULE object data. A Module Reference parameter is an InOut parameter of the MODULE data type that points to the MODULE Object of a hardware module. You can use module reference parameters in both Add-On Instruction logic and program logic.

For more information on the Module Reference parameter, see the Logix 5000 Controllers Add-On Instructions Programming Manual, publication 1756-PM010, and the Logix Designer application online help.

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Logic Execution Chapter 4
The Path attribute is available with Logix Designer application, version 24.00.00 and later. This attribute provides a communication path to the module.
For more information on the attributes available in the MODULE object, see the Logix 5000 Controllers General Instructions Reference Manual, publication 1756-RM003.

Develop Application Code in Each routine contains logic in one programming language. Choose a

Routines

programming language that is based on the application.

Section of Code Represents Continuous or parallel execution of multiple operations (not sequenced) Boolean or bit-based operations Complex logical operations Message and communication processing Machine interlocking Operations that service or maintenance personnel can interpret to troubleshoot the machine or process. Servo motion control Continuous process and drive control Loop control Calculations in circuit flow High-level management of multiple operations Repetitive sequences of operations Batch process Motion control sequencing (via sequential function chart with embedded structure text) State machine operations Complex mathematical operations Specialized array or table loop processing ASCII string handling or protocol processing

Language to Use Ladder Diagram(LD)
Function block diagram (FBD) Sequential function chart (SFC)
Structured text (ST)

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Comparison of Programming Languages

Comparison Instruction categories

Relay Ladder Logic
� Boolean � General and trig math � Timers and counters � Array management � Diagnostic � Serial port and messaging � ASCII manipulation � Motion control

Editor style Monitoring Comments

� Graphical rungs � Unlimited rungs
� Rung animation � Data value animation � Force status
� Tag � Rung

Function Block Diagram � General and trig math � Timers and counters � Bitwise logical � Advanced process � Advanced drive
� Graphical, free-form drawing � Unlimited sheets � Output and input pin data value
animation
� Tag � Text box

Sequential Function Chart

Structured Text

� Step/action with embedded structured text
� Transition with structure text comparisons
� Simultaneous and selection branches
� Stop element

� General and trig math � Timers and counters � Bitwise logical � Array management � Diagnostic � ASCII manipulation � Specialty CPU control � Motion control � Advanced process � Advanced drive

� Graphical, free-form drawing � Textual

� Unlimited grid space

� Unlimited lines

� Active steps animation � Auto display scroll � Branch/transition force status

� Tag watch pane � Context coloring

� Tag

� Multi-line

� Text box

� End if line

� Embedded structured text

� Comments that are stored in CPU

comments that are stored in CPU

Programming Methods

The capabilities of the controllers make different programming methods possible. There are trade-offs to consider when selecting a programming method.

Inline Duplication
Write multiple copies of the code with different tag references.
Benefits � Uses more memory � Fastest execution time because all tag references
are defined before runtime � Easiest to maintain because rung animation
matches tag values � Requires more time to create and modify

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Indexed Routine
Write one copy of code and use indexed references to data stored in arrays.
Benefits � One copy of code is faster to develop � Slowest execution time because all tag references
are calculated at runtime � Can be difficult to maintain because the data
monitor is not synchronized to execution

The JSR instruction passes the index.

Each indexed reference adds to scan time.

Buffered Routine

Copy the values of an array into tags to directly reference these buffer tags.

Benefits � One copy operation can occur faster than multiple
index offsets � Minimizes the need to calculate array offsets at
runtime � The amount of code increases, but so do the
benefits � Can be difficult to maintain because the data
monitor is not synchronized to execution

A user-defined structure consolidates control data.
Direct reference to a local copy of data.

The JSR instruction passes all control instance data.

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Controller Prescan of Logic

On transition to Run mode, the controller prescans logic to initialize instructions. The controller resets all state-based instructions, such as outputs (OTE) and timers (TON). Some instructions also perform operations during prescan. For example, the ONSR instruction turns off the storage bit. For information on prescan, see the following resources:
� Logix 5000 Controllers General Instructions Reference Manual, publication 1756-RM003.
� Logix 5000 Controllers Process Control and Drives Instructions Reference Manual, publication 1756-RM006.

During prescan, input values are not current and outputs are not written.

Prescan Affects

Description

Relay ladder logic

The controller resets non-retentive I/O and internal values.

Function block diagram logic Along with resetting non-retentive I/O and internal values, the controller also clears the EnableIn parameter for every function block diagram.

Structured text logic

The controller resets bit tags and forces numeric tags to zero .
Use the bracketed assignment operator ([:=]) to force a value to be reset during prescan.
If you want a tag that is left in its last state, use the non-bracketed assignment operator (:=).

Sequential function chart logic Embedded structured text follows the same rules as listed previously.

Prescan differs from first scan in that the controller does not execute logic during prescan. The controller executes logic during first scan. The controller sets S:FS for one scan:
� During the first scan that follows prescan.
� During the first scan of a program when it has been uninhibited.
� Each time a step is first scanned (when step.FS is set). You can view the S:FS bit being set only from the logic that is contained in actions that execute during the first scan of their parent step (N, L, P, and P1).

Add-On Instruction Prescan Logic
An Add-On Instruction prescan logic executes after the main logic executes in Prescan mode. Use the prescan logic to initialize tag values before execution. For example, set a PID instruction to Manual mode with a 0% output before its first execution.
When an Add-On Instruction executes in Prescan mode, any required parameters have their data passed.
� Values are passed to Input parameters from their arguments in the instruction call.
� Values are passed out of Output parameters to their arguments defined in the instruction call.

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Controller Postscan of SFC Logic

Logic Execution Chapter 4
SFCs support an automatic reset option that performs a postscan of the actions that are associated with a step once a transition indicates that the step is completed. Also, every Jump to Subroutine ( JSR) instruction causes the controller to postscan the called routine. During this postscan:
� Output energize (OTE) instructions are turned off and non-retentive timers are reset.
� In structured text code, use the bracketed assignment operator ([:=]) to have tags reset.
� In structured text code, use the non-bracketed assignment operator (:=) to have tags that are left in their last state.
� Selected array faults, that is, 4/20 and 4/83, can be suppressed. When the fault is suppressed, the controller uses an internal fault handler to clear it. Clearing the fault causes the postscan process to skip the instruction containing the fault and continue with the next instruction. This occurs only when SFC instructions are configured for automatic reset.
Add-On Instruction Postscan Logic
When an Add-On Instruction is called by logic in an SFC Action and the Automatic Reset option is set, the Add-On Instruction executes in Postscan mode. An Add-On Instruction postscan routine executes after the main logic executes in Postscan mode. Use the postscan logic to reset internal states and status values or to disable instruction outputs when the SFC action completes.

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Chapter 4 Logic Execution
Timer Execution

Timers in the controllers store off a portion of the real-time clock each time they are scanned. The next time through, they compare this stored value against the current clock and then adjust the ACC value by the difference.
The controller uses native 32-bit data, so there is more space to store the time. The timer stores 22 bits at 1 ms/bit, which equates to 69.905 minutes (2**22 / 1000 ms per second / 60 seconds per minute) of padding before a timer overlaps.
If program execution skips timers, it appears as if the timers pause. Actually, the timers are overrunning themselves. Depending on when the timer logic next executes, the lost time varies ranges from 0...69.905 minutes.
Program execution can skip executing timers due to the following: � Subroutine not being called � Jumping over code � SFC action � Inactive SFC step � Event or periodic task not executing � Equipment phase state routines
SFC Step Timer Execution
An SFC step timer stores the clock time each time the step executes. On subsequent scans of the step, the controller compares the current clock time with the last scan and updates the step timer's ACC by the difference.
When you pause an SFC and then release the SFC, the step timer jumps forward by the duration of the pause. If you want a step timer to remain at its position during a pause:
� Latch a recovery bit when the chart pause is released. � Add an action to the step to store the step timer's.ACC value and restore
that value when the pause recovery bit is set.

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Edit an SFC Online

Logic Execution Chapter 4
When you edit an SFC online, the software initially makes the changes in the offline project. When you accept the changes, they are downloaded to the controller. If you transition the controller to test or untest edits, the controller resets the SFC and starts execution at the initial step. If you edit an SFC online, do the following:
� Plan when you test or untest edits to coincide with the SFC executing the initial step.
� Place structured text logic in subroutines to minimize the impact of online edits.
� Use an SFR instruction to shift SFC execution to the desired step programmatically.
In some cases, this can result in the SFC being out of sync with the equipment. Program logic in the initial step to check the last state and use an SFR instruction to change to the appropriate step, if needed. One method is to set an index number in an action of each step. Then when the restart occurs, use the SFR instruction to jump to appropriate step based on the index value.
As of firmware revision 18, the following online edits to an SFC no longer reset the SFC to the initial step:
� Modified structured text in actions and transitions � Physically moved steps, actions, and transitions on SFC sheets without
changing the wiring � Added, deleted, or modified text and description boxes � Modified indicator tags

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Chapter 4 Logic Execution
Notes:

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5 Chapter
Modular Programming Techniques

Modular programming guidelines support the delivery of standardized programming structures, conventions, configurations, and strategies. The goal of modular programming is to provide consistency.
� Faster and easier development of application software � Faster and easier testing of application software � More reliable application software � Improved maintenance and operation of application software � Improved interoperability with other equipment and systems

This chapter applies to these controllers, and where applicable, the controllers are known as:

Controller Family 5580 controllers 5380 controllers 5570 controllers 5370 controllers 5480 Controllers

Includes these controllers ControlLogix� 5580 and GuardLogix� 5580 controllers CompactLogixTM 5380 and Compact GuardLogix 5380 controllers ControlLogix 5570 and GuardLogix 5570 controllers CompactLogix 5370 and Compact GuardLogix 5370 controllers CompactLogix 5480 Controllers

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Guidelines for Code Reuse

Guideline Use user-defined data types (UDTs) to group data. Use Add-On Instructions to create standardized modules of code for reuse across a project.
Use program parameters to share data between programs.
Use partial import/export programs, routines, Add-On Instructions, and code segments to create libraries of reusable code.
Use subroutines to reuse code within a program.

Description
Within a UDT: � You can mix data types. � The tag names that you assign self-document the structure.
Use an Add-On Instruction to: � Encapsulate specific or focused operations, such as a Motor or Valve action. A Conveyor or Tank action is better
managed as a routine. � Create extensions to the base controller instructions. For example, create an Add-On Instruction to execute an
SLCTM 500 or PLC controller instruction not available in the Logix 5000TM controllers. � Encapsulate an instruction from one language for use in another language. For example, create a function block
PIDE instruction for use in relay ladder.
Program parameters: � Are publicly accessible outside of the program. � Support external HMI external access on an individual basis for each parameter.
Direct access lets the user reference program parameters in logic without configuring parameters in the local program. For example, if Program A has an output parameter that is called Tank_Level, Program B can reference the Tank_Level parameter in logic without creating a corresponding parameter to connect to Program A.
Partial import and export of routines and programs: � Provides more control over the scope of what is extracted from the project. � Provides reusable code for larger machine, cell, or unit control. � Promotes collaboration between multiple engineers, code standardization, and reuse.
The export .L5X file includes all pertinent information, including program configuration, code, user-defined data types, tags, and descriptions, in an XML-formatted, ASCII text file. Use partial import/export to: � Distribute code separately from the project .ACD file. � Edit and create programs and routines by using other editing tools.
Subroutines: � Can be created and used in standard and safety applications. � Pass User-Defined Structures (UDT). � Pass all input and output Parameters by value. � Subroutines require the most overhead to pass parameters when called. � Can only be called from within the program they reside.

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Naming Conventions
Component Name Controller Controller project Tag

Modular Programming Techniques Chapter 5

The following conventions are guidelines to help make an engineering library more reusable by other developers. These guidelines also help the resulting applications have a more consistent look and feel.
� Names that are meaningful (and readable) to people who use the application as a later date are most effective.
� Names use controller memory and have limited length, so keep them short by using abbreviations and acronyms. Use mixed case rather than underscore characters to indicate words.
� When you use acronyms, use those that are common or provided by industry standards.

Names for controller logic components must follow these guidelines. � The name must start with a letter, either upper or lower case � The name can contain as many as 40 characters; any mix of upper case letter, lower case letters, numbers, and underscore characters � Case is not significant. The controller interprets Mix_Tank the same and mix_tank. However, the software displays the case as entered � Underscores are significant. The controller interprets AB_CD as unique from A_BCD � You cannot have two or more underscore characters in a row � The name cannot end with an underscore.

Recommendations
Area, unit, or units the controller controls, underscore, type of controller Example:

Area/Unit + Type

Controller Name: Mixing:ControlLogix

Controller name, the letter C, 1-digit major revision number, underscore, 2-digit minor revision number Example:

Project in controller Mixing_CLX, Major Revision 1, Minor Revision 02

Application Name: Mixing_CLX_C2_092.ACD

Increment the minor revision number for any documented engineering change according to the code in the controller (for example, the code for minor process or equipment changes).
Increment the major revision number for any documented engineering change according to the code in the controller that implements a design change (for example, code that enhances or reduces controller functionality).

Prefix with the abbreviation of the type of tag Examples:

Interprocessor communication tag

IPC_

Input tag

I_

Output tag

O_

Remote I/O tag

RIO_

Control module class tag

Device ID_

Equipment module class tag

EM_

Equipment phase class tag

EP_

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Component Name I/O or communication module

Recommendations

Controller name, underscore, abbreviation of rack location (L=local, R=remote), underscore, the letter S, 2-digit slot number, underscore, abbreviation of function
Example Functions:

Analog input

AI

Analog output

AO

Discrete input

DI

Discrete output

DO

Analog input/output combination

AIO

Discrete input/output combination

DIO

Analog/discrete input/output combination ADIO

Serial data

SIO

Motion data

MIO

DeviceNet� data

DNET

EtherNet/IPTM data

ENET

ControlNet�

CNET

Examples:

Mixer123 Controller, Local chassis, Slot 4, Analog Module Name: M123_CLX_L00_S04_AO Output

Mixer123 Controller, Local chassis, Slot 12, Discrete Output

Module Name: M123_CLX_L00_S12_DO

Mixer123 Controller, Remote chassis #1, Slot 1, Module Name: M123_CLX_R01_S01_AI Analog Input

Mixer123 Controller, Remote chassis #1, Slot 2, Module Name: M123_CLX _R01_S02_AO Analog Output

Mixer123 Controller, Remote chassis #2, Slot 5, Module Name: M123_CLX _R02_S05_DI Discrete Input

Mixer123 Controller, Remote chassis #2, Slot 6, Module Name: M123_CLX _R02_S06_DO Discrete Output

Mixer123 Controller, Local chassis, Slot 5, Remote I/O

Module Name: M123_CLX _R02_S06_RIO

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Modular Programming Techniques Chapter 5

Parameter Name Prefixes

Parameter Function Command

Prefix Cmd_

Configuration

Cfg_

Status

Sts_

Error

Err_

Alarm

Alm_

Input

Inp_

Output

Out_

Reference

Ref_

Programming structures, such as Add-On Instructions and programs support parameters for passing values. The convention for prefixes is to abbreviate the function of the parameter to three letters and an underscore, followed by additional text to clarify the specific function.
Description
Designates a command input, either from the operator via the HMI or from the program. Examples: � Cmd_Reset: Clear faults and reset the process � Cmd_JogServo: Jog a servo axis � Cmd_FillTank: Fill a tank with a liquid
Designates a configuration value for the structure. Enter from the HMI or as part of a recipe. Examples: � Cfg_JogDirection: Selects the direction a servo jogs: 0=Positive, 1=Negative � Cfg_BulkFill: Selects the fill rate to use: 0=Slow Rate, 1=Fast Rate � Cfg_UserUnits: Selects the measure of volume to use: 0=mm, 1=m, 2=gal � Cfg_EnableInterlocks: Enable interlock functionality � Cfg_EnablePermissive: Enable permissive functionality
Status of the process within the structure. Examples: � Sts_Alarm: An alarm condition (such as a HI/LOW alarm) exists within the process � Sts_ER: An error with an instruction execution within the process has been detected � Sts_IndexComplete: The servo index move within the process has completed � Sts_FillInProcess: The tank filling process is underway
If the Sts_ER bit is on, the Err_ parameter indicates the actual error. This can be either a bit level or value level indication. � Bit level error recording supports multiple errors simultaneously, but can require a large number of indicators to
support all error states. � Value-based error annunciation supports a large quantity of errors within one indicator. However, this approach
requires that errors are annunciated one at a time. Examples: � Err_Value: A nonzero value indicates an error condition � Err_PCamCalcFault: Indicates that an error has occurred in an MCCP
If the Sts_Alm bit is on, the Alm_ parameter indicates which alarm is occurring. This can be either a bit-level or valuelevel indication. � Bit-level alarming supports multiple alarms simultaneously, but can require a large number of indicators to support
all alarm states. � Value-based alarm annunciation supports a large quantity of alarms within one indicator. However, this approach
requires alarms to be annunciated one at a time. Examples: � Alm_Value: A nonzero value indicates an alarm condition � Alm_TankHI: Indicates that a HI level condition has been detected within a tank
Real-time data used to drive the process. Designates a connection either to a real input point, a control device, or to data received from other processes. Examples: � Inp_ServoPosition: Variable providing the input value for a position of a servo � Inp_ServoRegistrationPosition: Input of the registration position of the servo � Inp_InterlockOK: Input indicating external interlocks are met � Inp_TankLevel: Variable providing the analog input for a tank'level � Inp_TankLevelFillRate
Real-time data driven from the process. Designates a connection to a real output point, a control device, or to data sent to other processes. Examples: � Out_GlueGun1: Output signal to turn of Glue Gun 1 � Out_ServoCorrectionDistance: Output of a servo registration correction distance � Out_OverflowValve: Output signal to open the Overflow Valve � Out_TankLevelError: Output of a difference between target and actual fill level of a tank
Complex data structures that combine input and output data.These structures pass data into a structure, where some process is performed. The results are then loaded back into the structure to be passed out of Add-On Instruction for use elsewhere. Example: Ref_PositionCamRecovery: Provides the data set for calculating a Position Cam with all offsets factored in, and the resulting Position Cam Profile to run in an MAPC instruction

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Parameter Function Parameter

Prefix Par_

Set point

Set_

Value Report Information Ready
Program Command (optional)

Val_ Rpt_ Inf_ Rdy_
PCmd_

Operator Command (optional)

OCmd_

Description
Variables that are received from an external source that can be internal or external to the program. Examples: � Par_MachineSpeed: Provides a machine's running speed � Par_TargetFillLevel: Provides a tank's target fill level
Variables received from an operator or HMI and are not part of an external source. Examples: � Set_MachineMaxSpeed: Provides the setting for a machine's maximum permissible speed � Set_TankHILevel: Provides the setting for a tank's HI alarm limit
Designates a value that might not be the primary output of the structure.
Designates a value that is typically used for reporting.
Non-functional data such as a revision level or name for displaying a faceplate.
Command-ready bits that are typically Booleans calculated inside the control routines to reflect whether the routine let states change commands. Used with HMI faceplates to enable or disable command buttons.
Command input for commands typically issued by the application program. Examples: � PCmd_ProgReq - Request for Program Mode made by the application (as opposed to Cmd_ProgProgReq) � PCmd_AutoReq - Request for Auto Mode made by the application (as opposed to Cmd_ProgAutoReq)
Command input for commands typically issued by the operator via the HMI. Examples: � OCmd_ProgReq - Request for Program Mode made by the operator (as opposed to Cmd_OperProgReq) � OCmd_AutoReq - Request for Auto Mode made by the operator (as opposed to Cmd_OperAutoReq)

Guidelines for Subroutines Follow these parameter guidelines for subroutines.

Guideline

Description

Input and Return parameters depend on the subroutine logic.

If the subroutine needs to know the previous state of any Return parameters (the values are used elsewhere in the project), these values should also be Input parameters: � If the subroutine contains latch/unlatch logic (holding circuits), intended outputs of the subroutine should be passed
into and returned from the subroutine. � If the subroutine does not contain latch/unlatch logic, intended outputs of the subroutine only need to be returned
from the subroutine.

Pass complete timers in and out of subroutines.

If a subroutine needs a timer, pass the complete timer tag to the subroutine as an input and return the complete timer tag as an output. Store the timer in a buffer tag outside of the subroutine.

Create a user-defined tag to pass large numbers Input Create and pass a UDT if you have several Input and Output parameters to save on execution time. The more parameters

and Output parameters

that you pass, the fewer nested JSRs you can perform.

Data types must match

For each parameter in an SBR or RET instruction, use the same data type (including any array dimensions) as the corresponding parameter in the JSR instruction. Using different data types can produce unexpected results.

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Guidelines for User-defined Data Types

A UDT lets you organize or group data logically, so that all of the data associated with a device (such as a pressure transmitter or variable-frequency drive) can be grouped.
� You can mix data types, such as real or floating point values, counters, timers, arrays, Booleans, and other UDTs, within one UDT.
� You can copy a UDT from one project to another, and even from one Logix controller type to another.
� A UDT is self-documenting based on the tag names you assign, and provides a logical representation of parts or subsystems.

Naming Conventions for User-Defined Data Types

Element Prefix_ UDT name

Description UDT_ Function or purpose of the UDT

Examples:
Inventory tracking tag Clean-in-place system Two-state valve control module in control module Water addition in equipment module

UDT_InventoryTracking UDT_CIP UDT_CMV2S UDT_EM

UDT Member Order
The order in which elements are listed in the UDT can have a significant impact on memory use if several BOOL, INT, or SINT elements are defined. Memory is allocated in 4-byte (32-bit) increments, and every DINT, REAL, STRING, or sub-UDT element always start at the beginning of a 4-byte boundary.

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For example, if the first element defined is a BOOL, it uses the first 4 bytes allocated to the UDT. Other BOOLs can be assigned immediately following without consuming any more memory, until the first 4 bytes are consumed. However, if the next element is a DINT, the DINT element allocates another 4 bytes even though the BOOL occupies only a single bit in the first 4 bytes. So for this example, the 31 bits of memory between the BOOL and the start of the DINT are allocated but are not accessible.
� UDT memory is allocated in 4-byte increments.
� Elements that occupy 4 bytes or more always start at a 4-byte boundary. These include DINT, REAL, STRING, any UDT, or any other complex data structure.
� Elements of smaller data types (BOOL, SINT, or INT) start on the next byte boundary that matches its size, so that all the data types in the UDT are fully contained in their respective 4-byte increments. For example, INT elements start on 2-byte boundaries, SINT elements follow at the next byte, and BOOL elements in succession occupy consecutive bits within a byte.
In the following example, the UDT on the left, UDT_Tank, has members arranged by function without regard for memory usage. This makes sense in the context of implementation, because members toward the top are ordinarily used in the software code.
However, the disjointed listing of data types in UDT_Tank consumes 25% more memory than the example UDT on the right, UDT_TankPacked. In UDT_TankPacked, the BOOL members are grouped according to their functionality, with the input BOOLs grouped at the top and the output BOOLs grouped at the bottom. As a result, the data type size is reduced from 80 bytes to 64 bytes.

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For 64 bit data types such as LINT, ULINT, and LREAL, it is necessary for proper operation that these be aligned on 8 byte boundaries.

The following two examples show how this alignment is accomplished within UDTs.

Data Type BOOL PAD LINT

Byte Offset or Size 0 7 8

Data Type DINT PAD LREAL

Byte Offset or Size 0 4 8

Guidelines for Add-On Instructions
Guideline Create Add-On Instructions in relay ladder, function block diagram, or structured text languages.
An Add-On Instruction supports parameters: � Input (copied in) � Output (copied out) � InOut (passed by reference)
Create and modify offline only.

An Add-On Instruction encapsulates commonly used functions or device controls. It is not intended for use as a high-level hierarchical design tool. Once an Add-On Instruction is defined in a project, it behaves similarly to the builtin instructions that are already available in the programming software. The Add-On Instruction appears on the instruction toolbar and in the instruction browser.
Description
Supports all Add-On Instructions and most built-in instructions. Excludes JSR/SBR/RET, JXR, FOR/BRK (relay ladder), SFR, SFP, SAR, IOT, and EVENT instructions. GSV/SSV instructions in an Add-On Instruction cannot reference the Module, Message, Axis, Motion Group, or Coordinate System class names. Add-On Instructions support function block, relay ladder, and structured text programming languages. Each of the Add-On Instruction logic areas can be any language. For example, the main logic can be function block and the prescan logic can be relay ladder.
You can create safety Add-On Instructions in a safety task.
� For Version 24 and earlier, you are limited to 512 total parameters: Input parameter + Output parameter + local tags (no limit on the number of InOut parameters)
� For Version 28 and later, you are limited to 40 InOut parameters, but no limit on the number of Input or Output parameters)
� 2 MB maximum data instance (parameters and locals) � Alarm, axis, axis group, coordinate system, message, motion group, and produced/consumed tags must exist at the
program or controller scope and passed as an InOut parameter � Can include references to controller-scoped tags, program-scoped tags, and immediate values. � Input and Output parameters are limited to atomic (BOOL, SINT, INT, DINT, REAL) data types. Use the InOut parameter
for LINT, user-defined, and structure data types. � DINT data types provide optimal execution. � Default values of parameters and local tags are used to initialize the data structure when a tag is created of the
instruction's data type. When an existing parameter or local tag's default value is modified, the existing tag instances for that instruction are not updated. When a parameter or local tag is added to the instruction definition, the tag's default value is used in the existing tags.
Online operation supports monitoring.
Modifications to Add-On Instructions are made offline. Make changes once to the Add-On Instruction definition to affect all instances.

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Guideline

Description

An Add-On Instruction executes like a routine.

A task with a higher execution priority can interrupt an Add-On Instruction. Use a UID/UIE instruction pair to make sure an Add-On Instruction's execution is not interrupted by a higher priority task.
If you have many parameters or specialized options, consider multiple Add-On Instructions
Calling many Add-On Instructions impacts scan time

The code within an Add-On Instruction can access Copy the local data to a parameter if you want to programmatically access it outside of an Add-On Instruction. data that is specified only via parameters or defined as local.

Use optional Scan mode logic to set up, initialize, or reset the Add-On Instruction code.

An Add-On Instruction can have logic along with the main logic for the instruction. � Prescan logic executes on controller startup. � Postscan logic executes on SFC Automatic reset. � EnableInFalse logic executes when rung condition is false.

Apply code signatures to Add-On Instructions for revision control.

Add-On Instructions can be sealed with a code signature. Use the code signature for revision control and to identify any changes. For safety controllers, the signature can be used to get T�V certification for a safety Add-On Instruction. For more information, see the Logix 5000 Controllers Add-On Instructions Programming Manual, publication 1756-PM010.

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Component Name Add-On Instruction

Modular Programming Techniques Chapter 5
Add-On Instruction Design Concepts
To be sure that specific data is passed into or out of the Add-On Instruction, use a required parameter. A required parameter must be passed as an argument in order for a call to the instruction for verification. To pass a required parameter in ladder diagrams and in structured text, specify an argument tag for the parameter.
� In a function block diagram, required Input parameters and Output parameters must be wired.
� In a ladder diagram, InOut parameters must have an argument tag. � If a required parameter lacks an associated argument, the routine that
contains the call to the Add-On Instruction does not verify.

Naming Conventions for Add-On Instructions

Recommendations
Start with the application name. Add a variant name, is applicable. Capitalize the first letter in all words in the name. Example:

PCam profile display
Suffix with underscore AOI, if space permits. Example:

PCamProfileDisplay

PCam profile display

PCamProfileDisplay_AOI

Comparison of Subroutines and Add-On Instructions

Comparison Accessibility Parameters Numeric parameters

Subroutine Within program (multiple copies) Pass by value No conversion, you must manage

Parameters data types

Atomic, arrays, structures

Parameter checking Data encapsulation
Monitor/debug
Supported programming languages Callable from Protection Documentation

None, you must manage All data at program or controller scope (accessible to anything) Logic that is animated with mixed data from multiple calls FBD, LD, SFC, ST FBD, LD, SFC, ST Locked and View Only Routine, rung, textbox, line

Execution performance

� JSR/SBR/RTN add overhead � All data is copied

Add-On Instructions Anywhere in controller (single copy) Pass by value or reference via InOut Automatic data type conversion for Input and Output parameters InOut parameters must match declared type exactly � Atomic data types as In or Out parameters � LINT, user-defined, and structure data types as InOut parameters Verification checks
Local data is isolated (only accessible within instruction) Logic that is animated with data from one calling instance
FBD, LD, ST
FBD, LD, SFC, ST Locked and View Only Instruction description, revision information, vendor, rung, textbox, line, extended help � Call is more efficient � InOut passed by reference

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Comparison Memory use Edit
Import/export

Subroutine Compact
Both code and data can be modified offline and online in a running controller
All routines are imported/exported in the full project .L5K file (protected routines can be excluded or encrypted) Individual LD rungs and references and tags/UDTs can be imported/exported via the .L5X file

Add-On Instructions
� Call requires more memory � All references need additional memory
Code modifications are limited to offline in the project file and require a new download Data values associated can be modified online and offline
All Add-On Instructions are imported/exported in the full project .L5K file (protected instructions can be excluded or encrypted) Individual Add-On Instruction definitions and code are imported/ exported via the .L5X file

Comparison Logic Controller accessibility
Logic checking Data

Comparison of Partial Import/Export and Add-On Instructions

Partial Import/Export

Add-On Instructions

Any program, equipment phase, routine, Add-On Instruction, or userdefined data type in the project can be imported/exported via .L5X file.

Create once (single copy) and use anywhere in the same controller project.

Import on-line with a running controller: � Add programs, routines, and Add-On Instructions � Existing programs and routines can be replaced � Create tags and UDTs � Name collisions are detected automatically and you are prompted to
rename or bind to existing components � The data values in the controller are maintained and new tags have their
values initialized from the import file

Existing Add-On Instructions can only be edited offline. New Add-On Instructions can be created online or offline.

You resolve conflicts on import.

The software verifies the components that you add to Add-On Instruction as you create it.

Editing member definitions of an Add-On Instruction maintains the values that are assigned to the parameters when: � Inserting, adding, or deleting members � Rearranging (moving) members � Renaming members � Changing the data types of members

Local data is isolated (only accessible within the instruction).

Values for members that are both renamed and moved in the same operation are not to be maintained.

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Guidelines for Program Parameters

Program parameters define a data interface for programs to facilitate data sharing. Data sharing between programs can be achieved either through pre-defined connections between parameters or directly through a special notation. Unlike local tags, all program parameters are publicly accessible outside of the program. Additionally, HMI external access can be specified on individual basis for each parameter.
Standard (non-Safety) parameters can be created, edited, and deleted while online with the controller. The following exceptions apply:
� Parameters cannot be deleted while online if they are connected/bound to other parameters, or if the control logic references them.
� InOut parameters cannot be deleted while online
� InOut bindings can only be changed online through a Partial Import Online (PIO) operation
A safety parameter cannot be connected with or bound to a standard parameter or controller-scoped tag. A safety connection cannot be created, modified, or deleted in a safety-locked project. Input, Output, and Public parameters support the External Access attribute. InOut parameters do not.

Program Parameter Input
Output
InOut Public

Description
� Input parameters (including members) can only support ONE connection. Only one source can be delivering the value to the input parameter. � Input Parameter values are refreshed before each scan of a program. The values do not change during the logic execution so you do not need to
write code to buffer inputs. � A program can write to its own input parameters. � Data values for Output parameters that are connected to controller scope tags or Public parameters are copied after the scan of a program. In a
project with multiple tasks, the data copy for a parameter that is of type BOOL, SINT, INT, DINT, LINT, or REAL will not be interrupted. A task switch can interrupt the data copy from an Output parameter to a controller scope tag or Public parameter, or any other predefined or userdefined data type.
� Output parameters (including members) can support multiple connections. For example, lets assume you have a BOOL input parameter in Program A and Program B named Input1a and Input1b. You can connect an output parameter in Program C to Input1a AND Input1b. As stated earlier, this is often referred to as fanning.
� Output Parameter values are refreshed AFTER each scan of a program. Updated output parameter values are NOT available to the parameters connected to that output parameter until the program execution is complete.
� Output parameters that are connected to Public parameters or controller scope tags are copied (pushed) at the end of the program execution. � An Output parameter can ONLY be connected to an InOut parameter if both the Output and InOut parameters are configured as Constants.
� InOut parameters can only support ONE connection. You cannot configure connections to any member of an InOut parameter. � InOut parameters are passed by REFERENCE, which means they simply point to the base tag. In other words, when an InOut parameter is used
in logic, the current value of the parameter that is connected to the InOut Parameter is used. � An InOut parameter can ONLY be connected to an Output parameter if both the Output and InOut parameters are configured as Constants. See
the tool tip for Output Parameters for a more detailed explanation. � InOut parameters CANNOT be changed online, unless using the Partial Import Online (PIO).
� Public parameters can support MULTIPLE connections. You can configure connections to the base Public parameter or any member of a Public parameter. This includes User-Defined Structures.
� Public parameters are updated when the source is updated. In other words, when a Public parameter value updates, it is immediately available to any higher priority tasks that are connected to that parameter.
� Public parameters can be aliased to Controller Scope Tags. If this functionality is desired, remember that the alias update is asynchronous to program execution. The public parameter contains the real-time value of the controller scope tag.

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Comparison Accessibility Parameters Numeric parameters
Parameters data types Parameter checking Data encapsulation
Monitor/debug Supported programming languages Callable from Protection Documentation Execution performance Memory use
Edit

Comparison of Program Parameters and Add-On Instructions

Program Parameters

Add-On Instructions

Within program (multiple copies)

Anywhere in controller (single copy)

Input / Output (pass by value), InOut (pass by reference), Public (pass Input / Output (pass by value), InOut (pass by reference) by value)

� Automatic data type conversion for Input and Output parameters � Automatic data type conversion for Input and Output parameters

� InOut parameters must match declared type exactly

� InOut parameters must match declared type exactly

Atomic, strings, arrays, structures

� Atomic data types as In or Out parameters � LINT, user-defined, and structure data types as InOut parameters

None, user must manage

Verification checks

All data at program or controller scope (accessible to anything). Programs can talk directly and exchange data between them. Local tags remain private to the Program. Cannot access Local Tags, only the parameters.
Online editable.

Local data is isolated (only accessible within instruction) Logic that is animated with data from one calling instance

FBD, LD, SFC, ST

FBD, LD, ST

FBD, LD, SFC, ST

FBD, LD, SFC, ST

--

Locked and View Only

--

Instruction description, revision information, vendor, rung, textbox,

line, extended help

� Programs can talk directly and exchange data between them. � InOut passed by reference

� Call is more efficient � InOut passed by reference

Compact. One Public parameters can be connected or bound to

� Call requires more memory

multiple Input, Output or InOut parameters to form a shared memory � All references need additional memory

space.

Online editable, and supports sub-element connections. Copy / Paste Code modifications are limited to offline in the project file and require

Programs without disturbing parameter configuration.

a new download

Data values associated can be modified online and offline

Compare Controller Organizer and Logical Organizer

The Controller Organizer presents program logic how the controller executes the logic. The Logical Organizer is configurable to present program logic how the user views the system.

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Model Physical
Procedural

6 Chapter
Structure Logic According to Standards
The ANSI/ISA-88.01-1995 (R2006) standard is the most recognized and broadly adopted standard for modular equipment control. Complementing ISA-88.01 is the ISA-TR88.00.02 technical report, which is also known as PackML. The ISA-TR88.00.02 technical report comes from the Organization for Machine Automation and Control (OMAC). The OMAC provides examples of how to apply ISA-88.01 in discrete manufacturing segments.
ISA refers to the International Society of Automation, an ANSI recognized Standards Development Organization (SDO).
� ISA-88 refers to a specific set of ISA standards, of which ISA88.01 is a subset.
� SP88 refers to the ISA working member group responsible for the creation and publication of the ISA-88 standards.
ISA-88 provides these models to define and understand the automation control requirements for manufacturing plants.
Description The physical model (also known as the equipment model) describes a hierarchical organization of equipment and the basic control capabilities that are associated with that organization. The physical model is a representation of the equipment in the plant that makes the product. The procedural model describes a multi-tiered, hierarchical model that defines the process capability and automation control in relation to the Physical Model to perform a task. The procedural model is a representation of how to use the equipment (described in the physical model) to make the product.

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Physical Model

The physical model (also known as the equipment model) describes a hierarchical organization of equipment and the basic control capabilities that are associated with that organization. The physical model is a representation of the equipment in the plant that is used to make the product.
Enterprise

Site

Area Process Cell

Unit
Equipment Module

Control Module
Control Module

Control Module
Control Module

Equipment Module
Equipment Module
Control Module
Control Module

Control Module
Control Module

Physical Model Component Enterprise Site Process cell

The physical model defines the automation components within a given environment, and determines modular areas and component interactions.
The physical model shows that an enterprise can contain multiple sites, and a site can contain multiple areas, down to the equipment modules and control modules that carry out the manufacturing process
Description
The company that owns the facilities.
The location of one facility.
A collection of one or more units that are linked together to perform a task or multiple tasks of the process for one or more products in a defined sequence. A process cell contains the units, equipment modules, and control modules that are needed to make one or more batches.

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Physical Model Component Unit (or machine) Equipment module
Control module

Structure Logic According to Standards Chapter 6
Description
A collection of related equipment modules and control modules that execute one or more processing activities. The unit corresponds to the logical grouping of mechanical and electrical assemblies that historically has been called a machine. The term unit can apply to either a single-function machine or a multi-functional machine.
A functional group of control modules, equipment modules, or both that execute a finite number of activities. The primary purpose of control in an equipment module is to coordinate the functions of other equipment modules and lower-level control modules. A process cell, unit, operator, or another equipment module can command an equipment module. An equipment module can be part of A unit, or a standalone equipment group can include an equipment module in a process cell. If engineered as a standalone equipment grouping, an equipment module can be an exclusive-use resource or a shared-use resource. The equipment module combines all necessary physical processing and control equipment that is required to perform the manufacturing process. The finite tasks that an equipment module is designed to carry out defines the scope of the equipment module. The terms control module and equipment module apply to the physical equipment as well as to the equipment entity. The following are examples of equipment modules. � A valve matrix used for material transfer between units (shared resource of process cell) � A level control for a tank (equipment module within a specific unit) � A vertical form-fill-seal machine's `sealing jaws control'(equipment module within a discrete unit)
Control module: A regulating device, state-oriented device, or combination thereof (typically, a collection of sensors, actuators, and other control modules) that is operated as a single device. Control that is normally found at this level directly manipulates actuators and other control modules. A control module can direct commands to other control modules, or to actuators that have been configured as part of the control module. Control of the process is affected through the equipment-specific manipulation of control modules and actuators. The control module is the lowest level grouping of equipment in the physical model that can carry out basic control. The following are examples of control modules. � An individual sensor or actuator � A state-oriented device that consists of an on/off automatic block valve with position feedback switches and that is
operated via the set point of the device � A header that contains several on/off automatic block valves that coordinates the valves to direct flow to one or
several destinations based on the set point directed to the header CM � A servo-controlled electronic gear or cam function (that is, a discrete unit), including its interlock and permissives. The following are typical control modules in a programming library:. � Analog output � Analog input with scaling and alarms � Reversing motor � Variable speed drive � Solenoid-operated 2-state valve � Motor-operated 2-state valve � PID with standard modes and deviation alarms

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Chapter 6 Structure Logic According to Standards
Separate a Process Unit into Equipment Modules and Control Modules
To create a modular control program, start with one of these approaches. � Identify the control modules in the process. Then group the control modules into equipment modules to be supervised and coordinated by procedural controls. � Determine the units (typically vessels containing a single batch at a time). Then determine the equipment modules (such as ingredient addition equipment, agitating equipment, thermal jacket temperature control equipment, and transfer out equipment) by reviewing the related equipment, piping, and instrumentation on a process and instrumentation diagram (P&ID). Then determine the control modules that are related to the equipment states that must be controlled (such as motors, valves, or other process control loops).
One way to organize application logic in the Controller Organizer is to create a separate folder for each unit.
Process Cell
Physical Model
Unit
Equipment Modules
Control Modules

Component Name Site Area
62

Physical Model Naming Conventions

Recommendations
Short, preferably single character abbreviation, all upper case, of the formal name of the site Example:

Site: My Site

Site Name: M

Building number prefixed by a site name, but with no separating underscore Example:
Area: Manufacturing Building (102) Area Name: M102

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Component Name Cell Unit
Equipment module Control Module

Structure Logic According to Standards Chapter 6

Recommendations

Two- to three-character abbreviation of the formal name of the cell Prefix with an area name and a single underscore (optional) Example:

Cell: Mixing

Cell Name: A102_MIX_123

In a unit class, prefix the unit name with UN and an underscore Example:

Unit Class: Mix Tank

Unit Name: (Machine)

Unit Class: Packer

Unit Name: UN_Pckr

In a unit instance, use the unit identification from the piping and instrumentation diagram (P&ID) All uppercase letters; use underscored instead of dashes Prefix the unit name with the area name, separated from the unit name by a single underscore Example:

Unit Instance: Mix Tank 1234

Unit Name: A102_MT1234

Machine Instance: Packaging Machine 1234

Unit Name: A102_PKR1234

In a unit program instance, add the unit identifier between the area name and the unit name Example:

Unit Instance Program Name:

A102_UN02_MT1234

Machine Instance Program Name:

A102_UN02_PKR1234

In a unit tag instance, prefix the tag with the unit name Example:

Unit Instance Tag Name:

MT1234

Machine Instance Tag Name:

PKR1234

Area name, underscore, letters EM, underscore, function abbreviation All uppercase letters Example:

EM Instance: Mix Tank 1234 Vessel Agitator

EM Name: MT1234_EM_Agitate

EM Instance: Packager 1234 Bag Forming

EM Name: PKR1234_EM_BagForming

In a control module class, prefix the name with CM and an underscore Example:

CM Class: PID Control Loop

CM Name: CM_PID

CM Class: Cylinder

CM Name: CM_Cylndr

In a control module instance, use all uppercase letters Area name, underscore, unit name, underscore, instrument name, loop sequence number Example:

CM Instance: Temperature Controller 01

CM Name: TC_01

CM Instance: Cylinder 01

CM Name: CY01

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Procedural Model
Procedural Model Component Procedure Unit procedure Operation Phase

The procedural model describes a multi-tiered, hierarchical model that defines the process capability and automation control in relation to the physical model to perform a task. The procedural model is a representation of how to use the equipment (described in the physical model) to make the product.
The procedural control that is laid out in the procedural model directs the equipment components, via the component interfaces, to perform the specific tasks out of the available capabilities, needed to produce a given product.
Description The general strategy for production within a process cell. A procedure is composed of unit procedures. A production sequence. Unit procedures are composed of operations. The single sequence necessary for the initiation, organization, and control of phases. Operations are composed of phases. The lowest level of a procedure that can accomplish an action. The intent of a phase is to cause or define a process-oriented action, while the set of steps in the phase is equipmentspecific. � A phase can be subdivided into smaller parts. � A phase can issue one or more commands or cause one or more actions. � The execution of a phase can result in additional commands.
Combine the procedural model with the physical model to reflect the hierarchy of control and equipment, as well as the vertical separation between process controls and procedural controls.
Process Cell
Unit Procedure
Operation

Phase

Equipment

Module

Control Module

Not all manufacturing processes require the procedural control to reside in the physical equipment.
In a distributed or flexible process, procedural control can reside outside the equipment, in what is called the control recipe. Examples of this type of manufacturing are large batch systems, material handling systems, or automotive assembly systems. Use of the control recipe lets manufacturers with different automation requirements separate procedural control and process control.

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Structure Logic According to Standards Chapter 6

The procedural control is where distributed and flexible control occurs, and where the need arises for a separation from process control.
Procedural Control
Procedure

Unit Procedure Operation
Phase

Equipment Control

Procedural Control in Equipment
Equipment Module

Process Control
Equipment Module

Control Module

Identify Operations and Phases
One way to organize application logic in the Controller Organizer is to add the procedural model as a separate folder of phases.
Process Cell Physical Model Unit Equipment Modules Control Modules
Procedural Model Phases

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Procedural Control Modes
Control Mode Automatic (procedural) Automatic (basic control) Semi-Automatic (procedural) Manual (procedural) Manual (basic control)

A control mode determines how equipment entities and procedural elements respond to commands and how they operate. The mode determines how the procedure progresses and who can affect that progression. For example, in a control module that contains basic control functions, such as an automatic block valve, the mode determines what drives the valve position and who can manipulate the position.

The ISA-88 standard defines the following modes.

Behavior
Transitions within a procedure are conducted without interruption as appropriate conditions are met.

Command
Operators can pause the progression, but can not force transitions.

Equipment entities are manipulated by their control algorithm.

Equipment entities cannot be manipulated directly by the operator.

Transitions within a procedure are conducted on manual commands as appropriate conditions are fulfilled.
Procedural elements within a procedure are executed in the order that is specified by an operator.

Operators can pause the progression or redirect the execution to an appropriate point.Transitions cannot be forced.
Operators can pause the progression or force transitions.

Equipment entities are not manipulated by their control Equipment entities can be manipulated directly by the

algorithm.

operator.

Procedural Control States

The ISA-88 standard defines the following states.

Control State Idle Running Complete Pausing
Paused
Holding Held Restarting
Stopping

Description
The procedural element is waiting for a Start command to cause a transition to the Running state.
The procedural element is operating normally.
The procedural element has run to completion and is now waiting for a reset command that prompts a transition to Idle.
The procedural element or equipment entity received a Pause command. This causes the procedural element to stop at the next defined safe or stable stop location in its normal Running logic. Once the procedural element has stopped, the procedural element automatically transitions from Pausing to Paused.
Once the procedural element is paused at a defined stop location, it transitions from a Pausing to Paused. The Paused state is usually used for short-term pauses. A Resume command starts a transition to the Running state, and the procedural element resumes normal operation immediately following the defined stop location.
The procedural element received a Hold command and is executing its Holding logic to put the procedural element or equipment entity into a known state. If no sequencing is required, then the procedural element or equipment entity transitions immediately to the Held state.
The procedural element completed its Holding logic and proceeded to the Held state. This state is usually used for a long-term stop. The procedural element or equipment entity waits for a further command to proceed.
The procedural element receives a Restart command while in the Held state and executes its restart logic to return to the Running state. If no sequencing is required, then the procedural element or equipment entity transitions immediately to the Running state.
The procedural element received a Stop command and is executing its Stopping logic that facilitates a controlled normal stop. If no sequencing is required, then the procedural element or equipment entity transitions immediately to the Stopped state.

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Structure Logic According to Standards Chapter 6

Control State Stopped Aborting
Aborted

Description
The procedural element or equipment entity completed its Stopping logic and waits for a Reset command to transition to an Idle state.
The procedural element received an Abort command and is executing its Abort logic that is the logic that facilitates a quicker, but not necessarily controlled, abnormal stop. If no sequencing is required, then the procedural element transitions immediately to the Aborted state.
The procedural element completed its Aborting logic and waits for a Reset command to transition to the Idle state.

Procedural Control Commands

The ISA-88 standard defines the following commands.

Command Start Stop
Hold
Restart Abort
Reset Pause Resume

Description

Valid States

Orders the procedural element to begin executing the normal Running logic.

Idle

Orders the procedural element to execute the Stopping logic.

Running Pausing Paused Holding Held Restarting

Orders the procedural element to execute the Holding logic.

Running Pausing Paused Restarting

Orders the procedural element to execute the Restarting logic to safely return to the Running state. Held

Orders the procedural element to execute the Aborting logic.

Running Pausing Paused Holding Held Restarting Stopping Stopped

Orders the procedural element to transition to an Idle state.

Complete Aborted Stopped

Orders the procedural element to pause at the next programmed pause transition within its sequencing logic and await a Resume command before proceeding.

Running

Orders a procedural element that is in the Paused state, due to either a Pause command or a Single Step Paused mode, to resume normal operation.

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Chapter 6 Structure Logic According to Standards

Component Name Procedure
Unit procedure
Operation
Phase

Procedural Model Naming Conventions

Recommendations
Use all upper case letters Prefix with type of procedure (such as RP for recipe procedure), underscore, abbreviation of procedure Example:

Recipe Procedure Class: Clean

Procedure Name: RP_CLEAN

For a procedure executed in a Logix controller, prefix with area name, underscore, cell name, underscore Example:

Mixing, Tank: Clean

Procedure Name: M102_MIX_RP_CLEAN

Use all upper case letters Prefix with UP, underscore, abbreviation of unit procedure Example:

Unit Procedure Class: Clean

Unit Procedure Name: UP_CLEAN

For a unit procedure executed in a Logix controller, prefix with area name, underscore, unit name, underscore Example:

Unit Procedure Class: Mix Tank Clean

Procedure Name: M102_TK2333_UP_CLEAN

Use all upper case letters Prefix with OP, underscore, abbreviation of operation Example:

Operation Class: Steam-In-Place

Operation Name: OP_SIP

For an operation executed in a Logix controller, prefix with area name, underscore, unit name, underscore Example:

Mix Tank: Steam-In-Place Operation

Operation Name: M102_TK2333_OP_SIP

Use all uppercase letters Unit identifier, underscore, function abbreviation, EP, underscore, abbreviation of phase Example:

EP Instance: Mix Tank 1234 Vessel Agitator

EP Name: MT1234_EP_Agitate

EP Instance: Packager 1234 Bag Forming

EP Name: PKR1234_EP_BagForming

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State Model

Structure Logic According to Standards Chapter 6
A state model helps program the equipment in a structured way, which results in the same behavior in all equipment throughout the plant.

Command Initial State
Idle Running Complete Pausing Paused Holding Held Restarting Stopping Stopped Aborting Aborted Resetting

Start No Command State
Running Complete
Paused
Held
Running Stopped
Aborted
Idle

Stop
Stopping Stopping Stopping Stopping Stopping Stopping Stopping
Stopping

Hold
Holding Holding Holding Holding Holding

Restart

Abort

Reset

State Transition Matrix

Aborting

Aborting

Idle

Aborting

Aborting

Restarting Aborting

Aborting

Aborting

Aborting

Aborting

Idle

Idle Aborting

Pause

Resume

Pausing Running

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Chapter 6 Structure Logic According to Standards
Notes:

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Produced and Consumed Data

7 Chapter

The controllers support the ability to produce (broadcast) and consume (receive) system-shared tags.
For two controllers to share produced or consumed tags, both controllers must be in the same backplane or attached to the same control network. You cannot bridge produced and consumed tags over two networks.

IMPORTANT

The actual number of produced and consumed tags that you can configure over ControlNet� or EtherNet/IPTM in a project depends on the connection limits of the communication module through which you produce or consume the tags.

For more information on produced and consumed tags, see the Logix 5000 Controllers Produced and Consumed Tags Programming Manual, publication 1756-PM011.

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Chapter 7 Produced and Consumed Data

Guidelines for Produced and Consumed Tags

Guideline

Description

You cannot bridge produced and consumed tags over different networks.

For two controllers to share produced or consumed tags, both controllers must be attached to the same network. You can produce and consume tags over ControlNet or EtherNet/IP networks.

Create the tag at controller scope.

You can only produce and consume (share) controller-scoped tags.

Limit the size of the tag to  500 bytes.

If you produce or consume a tag over a network, the tag must be  480 bytes. Network transfers require 20 bytes of data overhead.

Combine data that goes to the same controller.

If you are producing several tags for the same controller: � Group the data into one or more user-defined structures. This uses fewer connections than producing each
tag separately. � Group the data according to similar update intervals. To conserve network bandwidth, use a greater RPI for
less critical data.

The following atomic data types can be directly produced or consumed: DINT UDINT LINT ULINT REAL LREAL

The listed atomic data types can be produced or consumed individually or in arrays. Other atomic data types (BOOL,SINT,USINT,INT,UINT) cannot be done individually or in arrays and are required to be part of a data structure to be produced or consumed.

Data structures can be produced or consumed

Data structures include user-defined data types (UDT), strings, add-on-defined, predefined, and module-defined data structures. Data structures meeting the size requirements can be produced or consumed.

AXIS_CIP_DRIVE

Use AXIS_CIP_DRIVE to produce and consume axis data.

The data type in the producer and the consumer must match.

The data type for a produced or consumed tag must be the same in both the producer and the consumer.

Produce tags that are based on user-defined structures to The controller produces tags in 32-bit words. For devices that communicate in other word boundaries, such as 16-bit

non-Logix devices.

words, the resulting data in the target device can be misaligned. To help avoid misalignment, structure the produced

data in a user-defined structure.

Use a programmatic handshake to help ensure data is exchanged.

Produced tags continually transmit based on the RPI, so it can be difficult to know when new data arrives. You can set a bit or increment a counter that is embedded in the produced tag to identify to the consumer that new data is present. You can also provide a return handshake via a reverse produced/consumed tag, so that the original producer knows that the consumer received and processed the tag.

Use a CPS instruction to buffer produced and consumed data.

Use the CPS instruction to copy the data to the outgoing tag on the producer side. Then use another CPS instruction to copy the data into a buffer tag on the consumer side.
The CPS instructions provide data integrity for data structures greater than 32 bits.
Important: The controller inhibits all interrupts while it executes a CPS instruction.

Use unicast EtherNet/IP communication to reduce broadcast network traffic.

To reduce bandwidth use and preserve network integrity, some facilities block multicast Ethernet packets. You can configure a produced and consumed tag to use multicast or unicast connections. Unicast connections help with the following: � Reduce network bandwidth � Simplify Ethernet switch configuration

Monitoring produced and consumed data.

Group produced and consumed tags as members in user-defined structures whose first member is a CONNECTION_STATUS type. This technique helps monitor connection status between controllers without increasing execution time, such as using a GSV instruction to detect status.

Firmware revisions

When adding the Producer controller to the I/O configuration list of the Consumer controller, the firmware revision does not have to match. However, the rack size and slot number must be correct.

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Guidelines for Produced and Consumed Axis

Guideline

Description

You can configure a produced and consumed axis between controllers in a chassis or over an EtherNet/IP network.

Controllers that support motion support the AXIS_CIP_DRIVE data type for produced and consumed tags.

Use a produced and consumed axis to synchronize motion functions across multiple controllers.

Synchronize functions such as: � PCAM � GEAR � MDSC moves � Scheduled outputs � Registration events � Position-based interlocks (handshake)

Guidelines to Specify an RPI Rate for Produced and Consumed Tags

When configuring produced and consumed tags, you specify a requested packet interval (RPI) rate. The RPI value is the rate at which the controller attempts to communicate with the module.

Guideline

Description

Make sure that the RPI is equal to or greater than the NUT. You use RSNetWorxTM for ControlNet software to select the network update time (NUT) and the software schedules the network connections.
RSNetWorx software cannot schedule a ControlNet network if a module and/or produced/consumed tag on the network has an RPI that is faster than the network update time.

RPI of multicast tags

� For Studio 5000 Logix Designer� application version 24 and earlier: The smallest (fastest) consumer RPI determines the RPI for the produced tag. If multiple consumers request the same tag, the smallest (fastest) request determines the rate at which the tag is produced for all consumers.
� For Studio 5000 Logix Designer application version 28 and later: the first consumer of a produce tag determines the RPI at which data is produced. All subsequent consumers must request the same RPI value as the first consumer. Otherwise, the subsequent consumers fail to connect.

Guidelines to Manage Connections for Produced and Consumed Tags

Guideline Minimize the use of produced and consumed tags. Use arrays or user-defined structures. Configure the number of consumers accurately.
Multiple produced/consumed connections are linked.

Description
To reduce network traffic, minimize the size of produced and consumed tags. Also, minimize the use of produced and consumed tags to high-speed, deterministic data, such as interlocks.
When sending multiple tags to the same controller, use an array or user-defined structure to consolidate the data. The byte limit of  500 bytes per produced and consumed tag still applies.
Make sure the number of consumers that are configured for a produced tag is the actual number of controllers that consumes the tag. If you set the number higher than the actual number of controllers, you unnecessarily use up connections. The default is two consumers per produced tag.
If there are multiple produced and consumed connections between two controllers and one connection fails, all produced and consumed connections fail. Consider combining all produced and consumed data into one structure or array so that you only need one connection between the controllers.

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Chapter 7 Produced and Consumed Data

Configure an Event Task Based on a Consumed Tag

An event task executes automatically based on a preconfigured event occurring. One such event can be the arrival of a consumed tag.
� Only one consumed tag can trigger a specific event task.
� Use an IOT instruction in the producing controller to signal the production of new data.
� When a consumed tag triggers an event task, the event task waits for all data to arrive before the event task executes.

Compare Messages and Produced/Consumed Tags

Method Read/Write Message
Produced/Consumed Tag

Benefits
� Programmatically initiated � Communication and network resources that are only used when
needed � Support automatic fragmentation and reassembly of large data
packets, up to as many as 32,767 elements � Some connections can be cached to improve retransmission time � Generic CIPTM message useful for third-party devices
� Configured once and sent automatically based on requested packet interval (RPI)
� Multiple consumers can simultaneously receive the same data from a produced tag
� Can trigger an event task when consumed data arrives � ControlNet resources are reserved up front � Does not affect the scan of the controller

Considerations
� Delay can occur if resources are not available when needed � MSG instruction and processing can impact controller scan
(system overhead timeslice) � Data arrives asynchronous to program scan (use a programmatic
handshake or a UID/UIE instruction pair to reduce impact, no event task support) � Can add additional messages online in Run mode.
� Support limited to Logix 5000TM and PLC-5� controllers, and the 1784-KTCS I/O Linx and select third-party devices
� Limited to 500 bytes over the backplane and 480 bytes over a network
� Must be scheduled when using ControlNet � Data arrives asynchronous to program scan (use a programmatic
handshake or CPS instruction and event tasks to synchronize) � Connection status must be obtained separately � You can configure status information for a produced/consumed
tag � On an EtherNet/IP network, you can configure produced/
consumed tags to use multicast or unicast connections. � Cannot create additional produced/consumed tags online in Run
mode.

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8 Chapter

Data Structures

The controllers support IEC 61131-3 atomic data types, and compound data types, such as arrays, predefined structures (such as counters and timers), and user-defined structures.

Guidelines for Data Types

Follow these guidelines depending on the data type for your application.

Guideline Use DINT data types whenever possible
Group BOOL values into arrays

Description
The controllers perform DINT (32 bit) and REAL (32 bit) math operations. DINT data types use less memory and execute faster than other data types. Use the following data type: � DINT for most numeric values and array indexes. � REAL for manipulating floating point, analog values. � SINT (8 bit) and INT (16 bit) primarily in user-defined structures or when communicating with an external device that
does not support DINT values.
When you use BOOL values, group them into DINT arrays to best use controller memory and to make the bits accessible via FBC or DDT instructions.

Memory Memory that is reserved for a standalone tag Memory that is reserved for data in a user-defined structure
Memory that is used to access a tag in an ADD instruction

SINT
4 bytes
1 byte (8-bit aligned)
236 bytes

INT
4 bytes
2 bytes (16-bit aligned)
260 bytes

DINT
4 bytes
4 bytes (32-bit aligned)
28 bytes

REAL
4 bytes
4 bytes (32-bit aligned)
44 bytes

A tag uses additional memory in the controller to store the tag name and symbol, and allocate memory for data.
To manipulate SINT or INT data, the controller converts the values to DINT values, performs the programmed manipulation, and then returns the result to a SINT or INT value. This requires additional memory and execution time when compared to using DINT values for the same operation.

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Chapter 8 Data Structures
Arrays

This array One dimension

Stores Data like

Two dimension

Three dimension

BOOL[96] = 12 bytes
BOOL arrays use 32-bit increments of memory

An array allocates a contiguous block of memory to store a specific data type as a table of values.
� Tags support arrays in one, two, or three dimensions.
� User-defined structures can contain a single-dimension array as a member of the structure.

For Example

Tag name

Type

Dimension 0

Dimension 1

Dimension 2

one_d_array

DINT[7]

7

Total number of elements = 7 Valid subscript range DINT[a] where a=0...6

Tag name

Type

Dimension 0

-- Dimension 1

-- Dimension 2

two_d_array

DINT[4,5] 4

5

--

Total number of elements = 4  5 = 20 Valid subscript range DINT[a,b] where a=0...3; b=0...4

Tag name

Type

Dimension 0

three_d_array

DINT[2,3,4] 2

Dimension 1 3

Dimension 2 4

Total number of elements = 2  3  4 = 24 Valid subscript range DINT[a,b,c] where a=0...1; b=0...2, c=0...3

The data type you select for an array determines how the contiguous block of memory gets used.

SINT[10] = 12 bytes of memory (2 bytes unused) SINT arrays are padded to use any left over bytes
INT[5] = 12 bytes of memory (2 bytes unused) INT arrays are padded to use any left over bytes
DINT[3] = 12 bytes and REAL[3] = 12 bytes DINT and REAL arrays use 4-byte increments of memory

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Data Structures Chapter 8

Guidelines for Arrays

Guideline

Description

You can create arrays of most data types, except for ALARM_xxx, AXIS_xxx, COORDINATE_SYSTEM, ENERGY_xxx, HMIBC, MESSAGE, and MOTION_GROUP data types.

A subscript identifies an individual element within the array. A subscript starts at 0 and extends to the number of elements minus 1 (zero based). � Single-dimension arrays take less memory and execute faster than two-dimension or three-dimension arrays. � Direct references to array elements execute faster than indexed references. � An array can be as large as 2 MB. � If you create an array of structures, the memory for each element is allocated based on the structure definition.

Type of Array

Benefit

Considerations

Single (1) dimension

� Better support by native file instructions � Fully supported in user-defined structures and arrays � Smallest impact (execution time and memory) for
indexed references � Can create arrays when programming online

� Multiple arrays cannot be indirectly referenced like in PLC or SLCTM processors (such as, N[N7:0]:5)
� BOOL arrays are not directly supported by file instructions
� Can be changed only when programming offline

Double (2) dimension and Triple (3) dimension

� Can provide a more accurate data representation for a physical system
� Can emulate PLC file/word indirection with a twodimension array
� Can create arrays when programming online

� Larger impact (execution time and memory) for indexed references
� File manipulation requires extra code and file instructions
� Can only be changed when programming offline

Nest arrays.

The file instructions offer limited support for arrays. To work with array data, create a user-defined structure with one array as a member of the structure. Then create an array tag by using the user-defined structure as its data type.

Select the data type of the array based on the data While SINT and INT arrays can compact more values into a given memory area, they require additional memory and

and the instructions that manipulate that data.

execution time for each instruction that references the array.

Limit arrays to 2 MB of data.

The maximum array size is 2 MB. The software displays a warning if you try to create an array that is too large. The software also displays a warning if an array is 1.5...2 MB, even though these sizes are valid.

Edit arrays online and offline.

You can create arrays when online or offline. However, you can modify only the size or data type of an existing array when offline.

Indirect Addresses of Arrays

If you want an instruction to access different elements in an array, use a tag in the subscript of the array (an indirect address). By changing the value of the tag, you change the element of the array that your logic references.

When index equals 1, array[index] points here.

array[0] 4500 array[1] 6000

When index equals 2, array[index] points here.

array[2] 3000 array[3] 2500

When you directly reference an element in an array (such as MyArray[20]), uses less memory and executes faster than an indirect reference (MyArray[MyIndex]). You can also indirectly address bits in a tag (MyDint.[Index]).
If you use indirect addresses, use DINT tags because other data types require conversion and execute slower. For each indexed access to data, the controller recalculates the array index. If you access a specific array element multiple times, copy the data out of the array into a fixed tag and use that tag in subsequent logic.

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Operator + * / ** ABS ACS AND ASN ATN COS DEG FRD

Description Add Subtract/negate Multiply Divide Exponent (x to y) Absolute value Arc cosine Bitwise AND Arc sine Arc tangent Cosine Radians to degrees BCD to integer

You can also use an expression to specify the index value. For example: MyArray[10 + MyIndex].
� An expression uses operators to calculate a value.
� The controller computes the result of the expression and uses it as the index.
� These are valid operators.

Optimal DINT, REAL DINT, REAL DINT, REAL DINT, REAL DINT, REAL DINT, REAL REAL DINT REAL REAL REAL DINT, REAL DINT

Operator LN LOG MOD NOT OR RAD SIN SQR TAN TOD TRN XOR

Description Natural log Log base 10 Modulo divide Bitwise complement Bitwise OR Degrees to radians Sine Square root Tangent Integer to BCD Truncate Bitwise exclusive OR

Optimal REAL REAL DINT, REAL DINT DINT DINT, REAL REAL DINT, REAL REAL DINT DINT, REAL DINT

Guidelines for Array Indexes

Guideline
Use the SIZE instruction to determine the number of elements in an array.

Description
By determining the number of elements in an array at runtime, you can write reusable code that adjusts itself to meet each instance where it is used.

Use immediate values to reference array elements. Use DINT tags for array indexes.
Avoid using array elements as indexes.

The SIZE instruction returns the number of elements. Arrays are zero-based, so subtract 1 from the result to determine the last element position.
Immediate value references to array elements are quicker to process and execute faster than indexed references.
DINT tags execute the fastest. SINT, INT, and REAL tags require conversion code that can add additional scan time to an operation.
The controller does not directly support the use of an array element as the index to look up a value in another array. To work around this, you can create an alias to the element and then use this as the index. Or copy the element to a base tag and use that base tag as the index.

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Guidelines for User-defined Data Types (UDT)

Guideline

Description

Group members of the same data type within a structure. You can create members of most data types, except for AXIS, COORDINATE_SYSTEM, MOTION_GROUP, and MESSAGE data types.
Place members that use the same data type in sequence.

Arrays within a UDT can only be 1-dimension.
I/O data that is used in a UDT must be copied into the members.
Limit user-defined data types to 500 members.
Limit user-defined data types to 2 MB of data.
Limit the size of user-defined structures if they are to be produced and consumed tags.
Use the appropriate instruction to load data into a structure.
Use structure descriptions to automatically create tag descriptions. Online and offline editing.

The controller aligns every data type along an 8-bit boundary for SINTs, a 16-bit boundary for INTS, or a 32-bit boundary for DINTs and REALs. BOOLs also align on 8-bit boundaries, but if they are placed next to each other in a user-defined structure, they are mapped so that they share the same byte.
If you include an array as a member, limit the array to one dimension. Multidimension arrays are not permitted in a user-defined structure.
If you include members that represent I/O devices, you must use logic to copy the data into the members of the structure from the corresponding I/O tags. Make sure that the data type of the structure member matches the I/O data type to avoid data type conversion.
The controllers limit user-defined structures to 500 members. If you need more, consider nesting structures within the main structure.
The maximum UDT size is 2 MB. The software displays a warning if you try to create an UDT that is too large. The software also displays a warning if the UDT is 1.5...2 MB, even though these sizes are valid.
Produced and consumed tags are limited to 500 bytes over the backplane and 480 bytes if over a network. Linx-based software can optimize user-defined structures that are less than 480 bytes. UDT larger than the noted produced and consumed tag limits must use a MESSAGE instruction (MSG) if they are to be communicated.
Load input values into the user-defined structure at the beginning of the program and copy output values from the user-defined structure at the end of the program. � Single bit - Examine On (XIC) and Output Energize (OTE) instructions � Contiguous bits - Bit Field Distribute (BTD) instruction � Single value - MOV instruction � Multiple contiguous values -COP/CPS instruction
Enable the Use Pass-through Description workstation option (Tools > Options > Display) to display the descriptions you add to the members of structures for each tag that uses that structure data type.
You can create user-defined structures when online or offline. However, you can modify only an existing structure when offline.

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Select a Data Type for Bit Tags
Tag Type BOOL tag
MyBit:BOOL
BOOL array BitTable:BOOL[32]
DINT array FaultTable:DINT[3]
User-defined structure BitStructure
Bit1:BOOL Bit2:BOOL

Bits in a controller can exist as: BOOL tags, bits in a BOOL array, bits in elements of a SINT, USINT, INT, UINT, DINT, UDINT, LINT, ULINT array, members of a user-defined structure, or as bits in a SINT, USINT, INT, UINT, DINT, UDINT, LINT, ULINT member of a user-defined structure.

Description Each tag accesses a specific bit. Each tag uses 4 bytes. Benefits � Each bit has a specific tag

Considerations
� Requires extra bandwidth to communication � Uses more memory � Cannot use FBC/DDT bit file instructions

A BOOL array combines multiple bits into adjacent words (32-bit words).

Benefits

Considerations

� Consolidates multiple bits into one word � Better use of memory � Can address all bits in an array by using indirect
addressing

� BOOL data type only supported by bit instructions � Cannot use file instructions, copy instructions, or DDT/
FBC instructions

A DINT combines multiple bits into adjacent words.
Benefits
� Consolidates multiple bits into one word � File instructions, copy instructions, and DDT/FBC
instructions support DINT arrays � Lets you access the bits by element (word) and
bit number

Considerations
� Requires extra planning to indirectly address bits � Difficult to address bits in the array by using indirect
addressing

A user-defined structure combines multiple bits into adjacent, individually named words.

Benefits

Considerations

� Object based � Consolidates multiple bits into one word

� Third-party MMI/EOI products do not directly support structures.
� Cannot use FBC/DDT bit file instructions

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Data Structures Chapter 8

Serial Bit Addresses
Address Mode
Serial bit In PLC-5 or SLC software, this addressing mode is represented as /Bit
Word bit In PLC-5 or SLC software, this addressing mode is represented as Word/Bit

The BOOL B data table in the PLC-5� and SLCTM 500 processors supports two address modes that can address the same bit.
Description
Serial bit addressing references all bits as a contiguous list (array) of bits. For example, if you want to reference the third bit in the second word of a B file, specify B3/18. This method is similar to a BOOL array in a Logix 5000TM controller where you specify FaultBit[18].
Word bit addressing identifies a bit within a specific word. For example, B3:1/2 is the same as B3/18 from the serial bit example. This method is similar to accessing the bits of a SINT, INT, DINT array in a Logix 5000 controller where you specify FaultTable[1].2.

The Logix 5000 controller supports both of these addressing modes, but you cannot use both to reference bits in the same array due to conformance with the IEC 61131-3 standard. Choose the method that best meets your application needs. You can copy data between arrays by using both methods.

You can also use an expression to indirectly reference a bit in a DINT array by using a serialized bit number. For example:

Tag

MyBits : DINT[10]

BitRef : DINT

EndTag

MOV(34, BitRef )

XIC(MyBits[BitRef / 32].[BitRef AND 31])

where:

This expression

Calculates the

[BitRef / 32]

Element in the DINT array

If the tag MyBits is an INT or SINT, the divisor is 16 or 8, respectively.

[BitRef AND 31]

Bit within the element

If the tag MyBits is an INT or SINT, the mask value is 15 or 7, respectively.

The Diagnostic Detect (DDT) and File Bit Compare (FBC) instructions provide a bit number as a result of their operation. These instructions are limited to DINT arrays so you can use them to locate the bit number that is returned from the example above.

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Guidelines for String Data Types

String data types are structures that hold ASCII characters. The first member of the structure defines the length of the string; the second member is an array that holds the actual ASCII characters.

Guideline

Description

You can create a string data type that is longer or shorter than the default string data type.

The default string data type can contain as many as 82 characters. You can create custom-length string data types that range from 1 to 65535 characters.

Only some instructions support string data types.

These comparison instructions support string tags: EQU, NEQ, GRT, GEG, LES, LEQ, CMP. These serial port instructions support string tags: ARD, ARL, AWA, AWT. These string-handling instructions support string tags: STOD, DTOS, STOR, RTOS, CONCAT, MID, FIND, DELETE, INSERT, UPPER, LOWER, SIZE. These file instructions support string arrays: FAL, FFL, FFU, LFL, LFU, COP, CPS, FSC.

Use the SIZE instruction to determine the number of By determining the number of characters in a string at runtime, you can write reusable code that adjusts itself to meet

characters in a string.

each instance where it is used.

Use the DTOS, RTOS, and CONCAT instructions to embed tag values within a string.

The SLC 500 processor supports the ability to embed a data-table reference address within a string (inline indirection). The SLC 500 AWA and AWT instructions can then look up the data value and place an ASCII representation into the outgoing string. The Logix 5000 controller does not directly support this ability. Use the DTOS or RTOS instructions to convert a value to a string and the CONCAT instruction to merge characters with another string.

Set the LEN field to indicate the number characters that The LEN field in the string structure indicates how many characters are in the string. The programming software and the

are present.

controller instructions that manipulate strings use the LEN value to determine how many positions in the string DATA

array contain valid characters. Both the programming software and the instructions stop processing the DATA array once

they reach the LEN value.

PLC-5/SLC 500 Access of Strings

The ASCII A data table in the PLC-5 and SLC 500 processors uses a string format that is similar to the Logix string data type. The main difference is that the LEN field (length) in a PLC-5/SLC 500 processor is a 16-bit, INT value. The LEN field in a Logix 5000 controller is a 32-bit, DINT field. This difference can impact converted logic and data communication. The Logix 5000 controller converts the LEN field to the appropriate value and size when a PLC-5/SLC 500 message format is used to read or write a string.

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Configure Tags

Data Structures Chapter 8

A tag is a text-based name for an area of controller memory where data is stored. Tags are the basic mechanism to allocate memory, reference data from logic, and monitor data.

If you want the tag to

Then choose this type

Store a value for use by logic within the project

Base

Use another name for an existing tag's data

Alias

(can help simplify long, pre-determined tag names, such as for I/O data or user-defined structures)

Send (broadcast) data to another controller

Produced

Receive data from another controller

Consumed

For more information on I/O tags, see Communicate with I/O on page 89.

Guidelines for Base Tags

Use the following guidelines for base tags.

Guideline Create standalone atomic tags. Create user-defined structures
Use arrays like files to create a group of similar tags.
Take advantage of program-scoped tags.

Description
The controller supports pre-defined, standalone tags. � Atomic tags are listed directly in the Tag Editor and Data Monitor and can easily be found by browsing the alphabetical list. � Atomic tags can be created online, but the data type can be only modified offline. Using only atomic tags can impact HMI communication performance as more information must be passed and acted on.
User-defined structures (data types) let you organize your data to match your machine or process. � One tag contains all data that is related to a specific aspect of your system. This keeps related data together and easy to locate,
regardless of its data type. � Each piece of data (member) gets a descriptive name. � You can use the structure to create multiple tags with the same data layout. � User-defined structure can only be modified offline. Linx-based software optimizes user-defined structures more than standalone tags.
An array creates multiple instances of a data type under a common tag name. � Arrays let you organize a block of tags that use the same data type and perform a similar function. � You organize the data in one, two, or three dimensions to match what the data represents. � Arrays can be only modified offline. � Linx-based software optimizes array data types more than standalone tags. Minimize the use of BOOL arrays. Many array instructions do not operate on BOOL arrays, making it more difficult to initialize and clear an array of BOOL data.
If you want multiple tags with the same name, define each tag at the program scope (program tags) for a different program. This lets you reuse both logic and tag names in multiple programs. Avoid using the same name for both a controller tag and a program tag. Within a program, you cannot reference a controller tag if a tag of the same name exists as a program tag for that program.

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Guideline Use mixed case and the underscore characters. Consider alphabetical order.
Use leading zeroes (0) when numbers are part of tag names

Description
Although tags are not case-sensitive (upper case A is the same as lower case a), mixed case is easier to read. For example, Tank_1 can be easier to read than tank1.
The programming software displays tags of the same scope in alphabetical order. To make it easier to monitor related tags, use similar starting characters for tags that you want to keep together. For example, consider using Tank_North and Tank_South rather than North_Tank and South_Tank.
The programming software uses a simple sort to alphabetize tag names in the Tag Editor and Data Monitor. This means if you have Tag1, Tag2, Tag11, and Tag12, the software displays them in order as Tag1, Tag11, Tag12, and then Tag2. If you want to keep them in numerical order, name them Tag01, Tag02, Tag11, and Tag12.

Create Alias Tags

An alias tag lets you create one tag that represents another tag. � Both tags share the same value as defined by the base tag. � When the value of a base tag changes, all references (aliases) to the base tag reflect the change.

Guideline

Description

Upload behavior for alias tags.

For 5370 and 5570 controllers, there are situations when uploading a project file that instruction operands that use alias references can change. To avoid these situations with ladder instruction operands, do not use:
� Nested aliases (also known as an alias chain)
� Multiple aliases to the same tag
On an upload, the software uses a technique referred to as "best fit"to reconstruct instruction operands and operands that use an alias can change.
This does not apply to 5380, 5480 and 5580 controllers and on an upload, the aliases for these controllers are faithfully reproduced.

Alias tags do not affect controller execution. During download, the program is compiled into machine executable code and physical memory addresses. While the existence of an alias requires controller memory to store the name, the program performs the same operation for a reference with an alias or its associated base tag.

Access alias tags from Linx-based software. Because an alias tag appears as a standalone tag to Linx-based software, an alias tag that references a compound array or structure can require additional communication time. When you reference tags from Linx-based software or other HMI, it can be fastest to reference base tags directly.

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Data Structures Chapter 8

Guidelines for Data Scope
Controller scope
Program scope Phase scope

Data scope defines where you can access tags. Controller-scoped tags and parameters are accessible by all programs. Local tags are accessible only by the code within a specific program. Equipment Phases, like Programs, have parameters and local tags.

If you want to
Produce or consume data
Use a tag in multiple programs in the same project
Use a tag in a message (MSG) instruction
Use motion tags
Reuse the same tag name multiple times for different parts or processes within a controller
Have multiple programmers work on logic and you want to merge logic into one project

Then assign this scope Controller scope (controller tags) Controller scope (controller tags) Parameters
Parameters Local Tags

Isolate portions of a machine or different stations into separate programs or equipment phases and use program-scoped or phase-scoped tags. This lets you do the following:
� Provide isolation between programs and equipment phases
� Help prevent tag name collisions
� Improve the ability to reuse code

See publication 1756-PM021, Logix 5000 Controllers Program Parameters Programming Manual, for more information on Parameters.

Guidelines for Tag Names Use the following guidelines when you name tags.

Guideline

Description

Create descriptive names but keep them short.

Tag names can be from 140 characters long. � Each character of the tag name uses 1 byte of controller memory, rounded to a 4-byte boundary. � For example, a tag name with 1...4 characters uses 4 bytes. A tag name with 5 characters uses 8 bytes. � Tag names are stored in the controller. � Use structures to reduce the number and size of tags needed.
Program upload preserves tag names.

Create a naming convention.

Develop a tag-naming convention on electrical drawings or machine design. For example, Conv1_Full_PE101 combines the sensor function with the photoeye number.

Use correct characters in tag names.

Tag names follow the IEC 61131-3 standard. You can use: � Letters A through Z. � Numbers 0...9. � Underscore character (_).
Tags must start with a letter to avoid confusion with logical expressions. The remaining characters can be any of the supported characters.

Pad names to improve sort order.

The programming software displays tags in alphabetical order. If you use numbers in your tag names, pad the number with leading zeros so the names sort in the proper order.
For example, tag names: TS1, TS2, TS3, TS10, TS15, TS20, TS30 display as: TS1, TS10, TS15, TS2, TS20,TS3, and TS30.
Pad the numbers with zero so they display as: TS01, TS02, TS03, TS10, TS15, TS20, TS30.

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Guidelines for Extended Tag Use the following guidelines for extended tag properties. Properties

Guideline

Description

Use extended tag properties to define additional information, such as limits, engineering units, or state identifiers, for various components within your controller project.

You can define extended tag properties for these components: � Tag � Parameter � User-defined data type � Add-On Instruction

Some extended tag properties support passthrough for data structures and arrays.

Pass-through behavior is available for descriptions, state identifiers, and engineering units and is configurable in data structures and arrays.
Pass-through behavior is not available for limits.

You can read extended properties via logic, but you cannot write to extended properties values in logic.

� Extended properties must be used as an input operand. � Alias tags with extended properties cannot be accessed in logic. � Limits can be configured for input and output parameters in Add-On Instructions. However, limit extended properties
must not be defined on an InOut parameter of an Add-On Instruction. � Limits cannot be accessed inside Add-On Instruction logic. � If you read an extended property value in logic, it consumes memory equivalent to an equivalent program-scoped tag of
that data type. If you do not use them in logic, extended tag properties use no user memory, only extended memory.

If an array tag uses indirect addressing to access limit extended properties in logic, the following conditions apply.

� If the array tag has limit extended properties that are configured, the extended properties are applied to any array element that does not explicitly have that particular extended property configured. For example, if the array tag MyArray has Max configured to 100, then any element of the array that does not have Max configured inherits the value of 100 when used in logic. However, it is not visible to you that the value inherited from MyArray is configured in the tag properties.
� At least one array element must have specific limit extended property configured for indirectly referenced array logic to verify. For example, if MyArray[x].@Max is being used in logic, at least one array element of MyArray[] must have Max extended property configured if Max is not configured by MyArray.
� Under the following circumstances a data type default value is used: � Array is accessed programmatically with an indirect reference. � Array tag does not have the extended property configured. � A member of an array does not have the extended property configured.

Tag Descriptions

The programming software searches a tag's origin to locate the first available description. This reduces the number of descriptions you need to enter. This also verifies that tag references display associated descriptions.

Guideline

Description

Tag descriptions display in the programming software according to the tag's origin.

Type of Tag Atomic

Alias
User-defined structure and Add-On Instruction
Atomic array

Structure array

Description Display in the programming software
For a BOOL, SINT, USINT, INT, UINT, DINT, UDINT, LINT, ULINT, REAL or LREAL tag, the description that is associated with the tag is the only description available for display.
First the alias tag description, then the base tag description.
All members use the description for tag, unless you define a specific description for a member. For example, MyTimer.DN uses the description for MyTimer if there is no description for MyTimer.DN.
� All references into an array use the description for the array, unless you define a description for an element of the array.
� For example, MyTable[10] uses the description for MyTable if there is no description for MyTable[10]. � All indexed references into an array use the description for the array. � For example, MyTable[Index] uses the description for MyTable.
All references to a member of a structure in an array default to the array definition, unless you define a description for the structure member of the array. For example, Table[0].Field1 uses the description for Table if there is no description for the specific field.

For more information, see the Create Tag Descriptions Automatically with User-Defined Data Types White Paper, publication LOGIX-WP004.

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Data Structures Chapter 8

Protect Data Access Control New tag attributes define access to tag data at runtime. at Tag Level

Tag Attribute External access
Constant

Description
Defines how an external application, such as an HMI, historian, or OPC data server, can access a tag. For arrays, this feature applies to the top level only; for user-defined structure, this feature applies to individual members. Possible values are: � Read/Write: External applications can both read and modify the tag's value � Read Only: External applications can read the tag's value, but not modify it � None: External applications can neither read or write the tag's value
Defines whether a tag value remains constant. Tags with this attribute set cannot be changed programmatically.

You can Use RSLinx� Classic software, version 2.56 or later, RSLinx Enterprise software, versions 5.21 to 5.90, or FactoryTalk� Linx software version 6.00 or later, for best results with these tag attributes. Using earlier versions of RSLinx software can result in anomalous behavior from the data servers with the external access options of Read Only and None.

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Notes:

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Buffer I/O Data

Communicate with I/O

9 Chapter

I/O values update at a period, requested packet interval (RPI), which you configure via Module Property dialog in the I/O configuration folder of the project. The values update asynchronously to the execution of logic.
The module sends input values to the controller at the specified RPI. Because this transfer is asynchronous to the execution of logic, an I/O value in the controller can change in the middle of a scan.

If you reference an I/O tag multiple times, and the application could be impacted if the value changes during a program scan, you must buffer the I/O value. You can buffer an I/O tag by using input parameters or coping into a buffer tag. In your code, reference the buffer tag rather than the I/O tag.

IMPORTANT

Use the synchronous copy (CPS) instruction to buffer I/O data. While the CPS instruction copies data, no I/O updates or other tasks can change the data. Tasks that attempt to interrupt a CPS instruction are delayed until the instruction is done. Overuse of the CPS instruction can impact controller performance by keeping all other tasks from executing.

Buffer I/O data to do the following: � Help prevent an input or output value from changing during the execution of a program (I/O updates asynchronous to the execution of logic). � Copy an input or output tag to a member of a structure or element of an array. � Help prevent produced or consumed data from changing during the execution of a program. � Make sure all produced and consumed data arrives or is sent as a group (not mixed from multiple transfers). � Only use the CPS instruction if the I/O data that you want to buffer is greater than 32 bits (or 4 bytes) in size.
Overuse of the CPS instruction can greatly impact controller performance.
If you have a user-defined structure with members that represent I/O devices, you must use logic to copy the data into the members of the structure from the corresponding I/O tags.

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Guidelines to Specify an RPI Configure an RPI rate per module (ControlLogix�) or an RPI rate per

Rate for I/O Modules

controller (CompactLogixTM). The RPI value is the rate at which the controller attempts to communicate with the module.

Guideline

Description

Specify an RPI at 50% of the rate you need new data.

If you set the RPI faster (specify a smaller number) than what your application needs, it can waste network resources, such as ControlNet� schedule bandwidth, network processing time, and CPU processing time.
For example, if you need information every 80 ms, set the RPI at 40 ms. The data is asynchronous to the controller scan, so you sample data twice as often (but no faster), you ensure that you have the most current data.

Group devices with similar performance needs onto By grouping devices with similar performance needs on the same module, you consolidate data transmission to one

the same module.

module rather than multiple modules. This conserves network bandwidth.

Set the ControlNetTM network update time (NUT) equal to or less than the fastest RPI.

When configuring a ControlNet network, set the network update time (NUT) equal to or less than the fastest RPI of the I/O modules and produced/consumed tags in the system. For example, if your fastest RPI is 10 ms, set the NUT to 5 ms for more flexibility in scheduling the network.

In an ControlNet system, use even multiples of the Set the RPI to a binary multiple of the NUT. For example, if the NUT is 10 ms, select an RPI such as 10, 20, 40, 80, or

NUT for the RPI value.

160 ms.

In a ControlNet system, isolate I/O communication.

If you use unscheduled ControlNet communication or want to be able to add ControlNet I/O at runtime (see page 98), dedicate one ControlNet network to I/O communication only. On the dedicated I/O network, make sure that there is the following: � No HMI traffic � No MSG traffic � No programming workstations � No peer-to-peer interlocking in multi-processor system architectures

In an EtherNet/IPTM system, module change of state is If you configure change of state communication for a module in a remote chassis that is connected via an EtherNet/IP

limited to 1/4 of the RPI.

network, the module can send data only as fast as the module RPI. Initially, the module sends its data immediately.

However, when an input changes, the module data is held at the adapter until 1/4 of the RPI is reached to avoid

overloading the EtherNet/IP network with the module communication.

Data transmission depends on the controller.

The type of controller determines the data transmission rate. � ControlLogix controllers transmit data at the RPI you configure for the module. � CompactLogix controllers transmit data at powers of 2 ms (such as 2, 4, 8, 16, 64, or 128). For example, if you specify an
RPI of 100 ms, the data actually transfers at 64 ms.

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Communication Formats for I/O Modules

The communication format determines whether the controller connects to the I/O module via a direct or a rack-optimized connection. The communication format also determines the type and quantity of information that the module provides or uses.

Direct Connection Each module passes its data to/from the controller individually.
Communication modules bridge data across networks.

Digital Inputs

Digital Outputs

Controller

Communication Module

Communication Module

Benefits
� Each module can determine its own rate (RPI) � More data can be sent per module, such as diagnostic and analog data � Supports event task communication

Local Chassis

Remote Chassis

Considerations
� Requires additional connections and network resources � This is the only method that is supported in the local chassis � I/O data is presented as individual tags

Rack-optimized Connection The communication module in a remote chassis consolidates data from
multiple modules into one packet and transmits that packet as one connection to the controller.

Digital Inputs

Digital Outputs

Controller

Communication Module

Communication Module

.
Benefits � One connection can service a full chassis of digital modules � Reduces network resources and loading

Local Chassis

Remote Chassis

Considerations
� All Modules are sent at the same rate � Unused slots are still communicated � Still need a direct connection for analog and diagnostic data � Limited to remote chassis � I/O data is presented as arrays with alias tags for each module

The rack-optimized format limits data to one 32-bit input word per module in a chassis. If you place a diagnostic module in a chassis, the rack-optimized format eliminates the value that the diagnostic module offers. In this case, it's better to use a direct connection so that the diagnostic information from the module is passed to the controller.

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Peer Control Output modules let peer ownership of input modules to consume input data to
directly control outputs without requiring controller processing.
The 1756-IB16IF and 1756-IB16IFC modules can be listened to presuming the output module knows the input data layout and connection information. The configuration from the controller defines how the peer input data is mapped to the output modules. The controller can use the other digital points on the module that are not peer-owned as conventional outputs.
The controller can also use the output data it normally sends to the module with consumed inputs, letting `gate-type' features enabled by controller logic selectively letting application of the consumed peer input data.
Connection / Peer Control Output Data

Connection

Listen Only

I

O

N

U

P

T

U

P

T

U

T

Input

Input

Output Echo

.

Benefits

Considerations

� Faster response time because the controller scan time is removed from the equation. Data is sent directly to the output module from the input module.
� Increases controller performance by reducing the need for event tasks to close loops quickly.
� Each input module has an AND and OR bit mask that defines the logic that is applied to each input module.

� You must program the controller for proper relationship with the output modules. � The peer output module must be in the same chassis as the input module to
maximize response time.

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Electronic Keying

Communicate with I/O Chapter 9

Electronic Keying reduces the possibility that you use the wrong device in a control system. It compares the device that is defined in your project to the installed device. If keying fails, a fault occurs. These attributes are compared.

Attribute Vendor Device Type Product Code Major Revision Minor Revision

Description The device manufacturer. The general type of the product, for example, digital I/O module. The specific type of the product. The Product Code maps to a catalog number. A number that represents the functional capabilities of a device. A number that represents behavior changes in the device.

The following Electronic Keying options are available.

Keying Option Compatible Module
Disable Keying
Exact Match

Description
Lets the installed device accept the key of the device that is defined in the project when the installed device can emulate the defined device. With Compatible Module, you can typically replace a device with another device that has the following characteristics: � Same catalog number � Same or higher Major Revision � Minor Revision as follows:
� If the Major Revision is the same, the Minor Revision must be the same or higher. � If the Major Revision is higher, the Minor Revision can be any number. This is the default selection in the Logix Designer application.
Indicates that the keying attributes are not considered when attempting to communicate with a device. With Disable Keying, communication can occur with a device other than the type specified in the project. ATTENTION: Be cautious when using Disable Keying; if used incorrectly, this option can lead to personal injury or death, property damage, or economic loss. We strongly recommend that you do not use Disable Keying. If you use Disable Keying, you must take full responsibility for understanding whether the device being used can fulfill the functional requirements of the application.
Indicates that all keying attributes must match to establish communication. If any attribute does not match precisely, communication with the device does not occur.

Carefully consider the implications of each keying option when selecting one.

IMPORTANT

When you change Electronic Keying parameters online, it interrupts connections to the device and any devices that are connected through the device. Connections from other controllers can also be broken.
If an I/O connection to a device is interrupted, the result can be a loss of data.

More Information
For more detailed information on Electronic Keying, see Electronic Keying in Logix 5000TM Control Systems Application Technique, publication LOGIXAT001.

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Guidelines to Manage I/O Connections
Use the following guidelines to administer your I/O modules.

IMPORTANT Compact 5000TM I/O does not support rack-optimization.

1. The type of I/O module can determine the type of connection.
� Analog modules always use direct connections, except for 1771 analog modules that use messaging and 1734 analog modules that use Enhanced Rack Optimization.
� Digital modules can use direct or rack-optimized connections. Communication formats that include optimization in the title are rack-optimized connections; all other connection options are direct connections.
2. Select the communication format for a remote adapter based on the remote I/O modules.

Select None Rack-optimized
Listen Only Rack-optimized

If
The remote chassis contains only analog modules, diagnostic digital modules, fused output modules, or communication modules. On a ControlNet network, use None to add a chassis to the network while the controller is running.
The remote chassis only contains standard, digital input, and output modules (no diagnostic modules or fused output modules). For a ControlNet network at runtime (controller is online), you can add new digital modules to an existing rack-optimized connection, but new rack-optimized connections can only be added when offline. An EtherNet/IP network supports new rack-optimized connections both offline and at runtime (online). For more information, see page 98.
You want to receive I/O module and chassis slot information from a rack-optimized remote chassis that is owned by another controller. The runtime capability for listen only rack-optimized connections is the same as for rack-optimized connections.

3. Use rack-optimized connections to conserve connections.
If you are trying to limit the number of controller and network connections, rack-optimized connections can help.
4. In some cases, all direct connections work best.
For a remote adapter that is configured for rack-optimized connections, there is always data that is sent for each slot in the chassis, even if a slot is empty or contains a direct connection module. There are 12 bytes of data that is transferred for rack-optimized overhead between the controller and the remote adapter. In addition, the remote adapter sends 8 bytes per slot to the controller; the controller sends 4 bytes per slot to the remote adapter.

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For a few digital modules in a large chassis, it can be better to use direct connections because transferring the full chassis information can require more system bandwidth than direct connections to a few modules.

Example Remote 17-slot chassis Slot 0: 1756-CNBR/D Slots 1...15: analog modules Slot 16: standard digital module
Remote 17-slot chassis Slot 0: 1756-CNBR/D Slots 1...8: analog modules Slots 9...16: digital modules

Description
Option 1: Select Rack Optimization as the communication format for the remote adapter. This example uses 16 controller connections (15 for analog modules and 1 for the rack-optimized connection). This example also transfers: � 12 bytes for rack-optimized overhead. � 12 bytes for the digital module. � 12 bytes for each of the 15 analog modules, for a total of 180 bytes.
Option 2: Select None as the communication format for the remote adapter. This example also uses 16 controller connections (1 direct connection to each I/O module). There is no rack-optimized overhead data to transfer.
Recommendation: Option 2 is recommended because it avoids unnecessary network traffic, and thus improves network performance.
Option 1: Select Rack Optimization as the communication format for the remote adapter. This example uses nine controller connections (eight for analog modules and one for the rack-optimized connection). This example also transfers: � 12 bytes for rack-optimized overhead. � 12 bytes for each of the 8 digital modules, for a total of bytes 96 bytes. � 12 bytes for each of the 8 analog modules, for a total of 96 bytes.
Option 2: Select Rack Optimization for the communication format of the remote adapter. This example uses 16 controller connections (1 direct connection to each I/O module). There is no rack-optimized overhead data to transfer.
Recommendation: The best option for this example depends on the type of digital I/O modules in the system and other controller connections. If the total system has many analog modules, diagnostic modules, fused output modules, or produced/consumed tags, select Option 1 to conserve controller connections. If there are plenty of controller connections available, select Option 2 to reduce unnecessary network traffic.

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Create Tags for I/O Data

Each I/O tag is automatically created when you configure the I/O module through the programming software. Each tag name follows this format:

This address variable Location
SlotNumber Type
MemberName SubMemberName Bit (optional)

Location:SlotNumber:Type.MemberName.SubMemberName.Bit

Is

Identifies network location LOCAL = local chassis or DIN rail ADAPTER_NAME = identifies remote adapter or bridge

Slot number of I/O module in its chassis

Type of data: I = input O = output

C = configuration S = status

Specific data from the I/O module, such as Data and Fault; depends on the module

Specific data that is related to a MemberName

Specific point on the I/O module; depends on the size of the I/O module (0...31 for a 32-point module)

If you configure a rack-optimized connection, the software creates a rackobject tag for the remote communication module. You can reference the rackoptimized I/O module individually, or by its element within the rack-object tag.

For example, a remote EtherNet communication module (Remote_ENT2R) has an I/O module in slot 1.
The individual tag that is created for the I/O module in remote slot 1.

The entry in the rack-object tag for the remote communication module that identifies the I/O module in remote slot 1.

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Controller Ownership
Mode Owner Listen-only

Controlling Input modules

This Ownership Owner

Output modules

Listen-only Owner Listen-only

When you choose a communication format, you have to choose whether to establish an owner or listen-only relationship with the module.
Description
The owner controller writes configuration data and can establish a connection to the module.
A controller that uses a listen-only connection only monitors the module. It does not write configuration data and can only maintain a connection to the I/O module when the owner controller is actively controlling the I/O module.
There is a noted difference in the ownership of input modules versus the ownership of output modules.
Description
An input module is configured by a controller that establishes a connection as an owner. This configuring controller is the first controller to establish an owner connection. Once an input module has been configured (and owned by a controller), other controllers can establish owner connections to that module. This lets additional owners to continue to receive multicast data if the original owner controller breaks its connection to the module. All other additional owners must have the identical configuration data and identical communication format that the original owner controller has, otherwise the connection attempt is rejected.
Once an input module has been configured (and owned by a controller), other controllers can establish a listen-only connection to that module. These controllers can receive multicast data while another controller owns the module. If all owner controllers break their connections to the input module, all controllers with listen-only connections no longer receive multicast data.
An output module is configured by a controller that establishes a connection as an owner. Only one owner connection can be connected to an output module. If another controller attempts to establish an owner connection, the connection attempt is rejected.
Once an output module has been configured (and owned by one controller), other controllers can establish listenonly connections to that module. These controllers can receive multicast data while another controller owns the module. If the owner controller breaks its connection to the output module, all controllers with listen-only connections no longer receive multicast data.

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Runtime/Online Addition of You can add modules when the controller is in Run mode. Modules

Network ControlNet network
EtherNet/IP network

Considerations
You can use: � 1756-CN2, 1756-CN2R, 1756-CN2RTXT any series modules. � 1756-CNB, 1756-CNBR series D or later communication modules.
Digital I/O modules can be added as rack-optimized connections if the parent module is already configured with rack-optimized connections. While you can add a new digital I/O module to an existing rack-optimized connection, you cannot add rack-optimized connections while online. Digital I/O modules can also be added as direct connections.
Analog I/O modules can be added only as direct connections.
Disable the Change of State (COS) feature on digital input modules because it can cause inputs to be sent more quickly than the RPI.
If you plan to add large amounts of I/O to the ControlNet network, dedicate one ControlNet network for I/O. For the dedicated ControlNet network, verify that there is little or no: � HMI traffic. � MSG traffic. � Programming workstations.
If the module has a Real Time Sample (RTS), disable it or set to a rate that is greater than the RPI.
Considerations for 1756-CN2, 1756-CN2R, 1756-CN2RXT Modules
You can add I/O modules until you reach these limits: � 80% of CPU utilization of the 1756-CN2, 1756-CN2R, or 1756-CN2RXT communication module. � Less than 400,000 unscheduled bytes per second are displayed in RSNetWorxTM for ControlNet software after the network has been scheduled.
Considerations for 1756-CNB, 1756-CNBR Modules
Requested Packet Intervals (RPIs) faster than 25 ms for unscheduled modules can overload the 1756-CNB or 1756-CNBR communication module. To avoid the overload, make these considerations: � Use a NUT of 10 ms or more. � Keep the SMAX and UMAX values as small as possible.
You can add I/O modules until you reach these limits: � 75% of CPU utilization of the 1756-CNB or 1756-CNBR communication module. � Plan for a CPU-use increase of 1...4% of the 1756-CNB or 1756-CNBR module for each I/O module you add, depending on RPI. � 48 connections on the 1756-CNB or 1756-CNBR communication module. � Less than 400,000 unscheduled bytes per second are displayed in RSNetWorx for ControlNet software after the network has been scheduled.
The EtherNet/IP I/O modules that you add at runtime can be: � Added to existing rack-optimized connections � Added to new rack-optimized connections � Added as direct connections (you can create rack-optimized connections when adding EtherNet/IP I/O modules at runtime)
You can add I/O modules until you reach the limits of the communication module:

1756-EN4TR, 1756-EN4TRXT Module

1756-EN2TR, 1756-EN3TR

� 50,000 pps without CIP Security
� 25,000 pps with integrity
� 15,000 pps with integrity and confidentiality

20,000 pps

512 TCP connections 128 TCP connections

CIPTM connected messages:
1000 I/O 528(1)

256 CIPTM connected messages

(1) There are 1000 explicit connections and 528 implicit connections.

1756-EN2T, 1756-EN2TP, 1756-EN2TXT, 1756-EN2F Module 10,000 pps
128 TCP connections 256 CIP connected messages

1756-ENBT Module 5069-AENTR, 5094-AENTxx
COMPACT 5000 I/O Ethernet Adapter

5000 pps

100,000 pps (total number of packets from both Ethernet Ports)

5069-AEN2TR COMPACT 5000 I/O Ethernet Adapter
100,000 pps (total number of packets from both Ethernet Ports)

64 TCP connections
128 CIP connected messages

32 TCP Connections
80 CIP Connected Messages

32 TCP Connections
320 CIP Connected Messages

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Online Addition of Module and Connection Types

Module Type and Connection Method

In Local Chassis

Remote via an

Remote via a ControlNet� Network

EtherNet/IP Network

Configure Hold Last Output State

Offline Runtime Offline Runtime Offline

Runtime

Offline only

Scheduled Unscheduled Scheduled Unscheduled

Digital - direct

Yes

Yes

Yes Yes

Yes

Yes

--

Yes

Yes - 1756 I/O digital output modules

Digital - rack-optimized

--

--

Yes Yes

Yes

--

Yes

--

Yes - 1756 I/O digital output modules

Analog - direct

Yes

Yes

Yes Yes

Yes

Yes

--

Yes

Yes

Generic third-party - direct Yes

Yes

Yes Yes

Yes

Yes

--

Yes

--

1715 Redundant I/O 1718/1719 I/O

--

--

--

--

Yes Yes

--

--

--

--

Yes

Yes

--

--

--

--

-- Yes � both analog and digital modules

1756-ENx - no connection Yes

Yes

Yes Yes

--

--

--

--

--

1756-ENx - rack-optimized --

--

Yes Yes

--

--

--

--

--

Generic EtherNet/IP third- --

--

Yes Yes

--

--

--

--

--

party - direct

1788-EN2FFR or 1788-EN2PAR

--

--

--

--

--

--

Yes

Yes

--

1788-CN2FFR or

--

--

Yes Yes

No

Yes

--

--

--

1788-CN2PAR

1794 FLEX I/O

--

--

Yes --

Yes

Yes

--

--

Yes - Analog output modules only

1734 POINT I/O

--

--

Yes --

Yes

Yes

--

--

Yes

1734 POINT Guard I/OTM

Yes

--

Yes --

--

--

--

--

--

5069 Compact 5000 I/O

Yes

--

Yes

Yes(1)

--

--

--

--

Yes

5069 Compact 5000 I/O Safety Yes

--

Yes --

--

--

--

--

--

Modules

5094 FLEX 5000

--

--

Yes Yes

--

--

--

--

Yes

5094 FLEX 5000 I/O Safety --

--

Yes --

--

--

--

--

Yes

Modules

(1) Only supported if adding an entire rack of Compact 5000 I/O modules.

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Design Issue I/O modules Other modules Input transmission rate Network topology
Network configuration
Network performance

Design Considerations for Runtime/Online Addition of Modules
When you design your network, address these considerations to add modules at runtime.
Considerations
If you plan to add 1756 I/O modules at runtime, leave space in the local chassis, remote chassis on a ControlNet network, or remote chassis on an EtherNet/IP network for the I/O modules you want to add.
You can add 1757-FFLDC devices remotely via the unscheduled portion of a ControlNet network at runtime.
Make sure the RPIs work for the data you want to send and receive. Make sure the added I/O does not depend on change of state data.
On a ControlNet network, install spare taps so you can add modules at runtime without disrupting the network. Each tap must be terminated not to ground out the system. Check ControlNet system requirements to determine how many spare taps your network can support. � In a ControlNet network with redundant cabling, you can break the trunk and add a tap, but redundant cabling is lost during the module
installation. � In a ControlNet ring, add a drop off the ring or add new nodes off the coax and disrupt only part of the network. � You could remove an existing node and add a repeater off that drop. Then reconnect the existing node and add any new nodes off the new
segment. On an EtherNet/IP network, reserve some connection points on the switch so that you can connect additional nodes or switches in the future.
On a ControlNet network, plan which communication can be scheduled or unscheduled. On an EtherNet/IP network, all communication is immediate and occurs based on the module RPI (also referred to as unscheduled). If you know that you need a new chassis with digital modules in the future, configure the network and add it to the I/O configuration tree as rack optimized. Then inhibit the communication adapter until you need the chassis.
You can add modules at runtime until you impact the capacity of the communication module. Make sure that you have sufficient communication modules for the connections you plan to add.

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Determine the Appropriate Network

Comparison Function Typical devices networked
Data repetition Number of nodes, max Data transfer rate Typical use
Design Issue Network topology
Network configuration Network performance Chassis Input transmission rate

EtherNet/IPTM, ControlNet�, and DeviceNet� networks share a universal set of communication services. These are the recommended networks for Logix control systems.

EtherNet/IP Network

ControlNet Network

Plant management system tie-in (material Supports transmission of time critical data handling); configuration, data collection, and between PLC processors and I/O devices control on a high-speed network

Mainframe computers Programmable controllers Robots HMI I/O Drives Process instruments

Programmable controllers I/O chassis HMIs PCs Drives Robots

Large packets, data sent regularly
Network overall: no limit 10 Mbps, 100 Mbps, or 1000 Mbps Plant-wide architecture High-speed applications Redundant Applications Safety Applications

Medium-size packets; data transmissions are deterministic and repeatable
99 nodes
5 Mbps
Redundant applications Scheduled communication

DeviceNet Network
Connects low-level devices directly to plant-floor controllers--without interfacing them through I/O modules
Sensors Motor starters Drives PCs Push buttons Low-end HMIs Barcode readers PLC processors Valve manifolds
Small packets; data is sent as needed
64 total nodes
500 Kbps, 250 Kbps, or 125 Kbps
Supply power and connectivity to low-level devices.

Follow these guidelines when planning a network.
Considerations
Plan for future connections. Plan for additional controllers and/or communication modules to handle future I/O modules. Consider distances between devices. Determine resiliency requirements.
On a ControlNet network, plan which communication can be scheduled or can be unscheduled. On an EtherNet/IP network, all I/O communication is based on the RPI of the module.
Make sure that you have sufficient communication modules for the connections you plan to use. Use available network performance tools.
Consolidate communication connections for multiple modules to one network node. Group digital I/O modules into a rack-optimized connection to reduce the amount of communication and network bandwidth.
Make sure the RPIs work for the data you want to send and receive. Make sure that I/O added at runtime does not depend on change of state data.

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EtherNet/IP Network Topology

This section features these controllers, and where applicable, the controllers are known as:

Controller Family 5580 controllers 5380 controllers 5570 controllers 5370 controllers

Includes these controllers ControlLogix� 5580 and GuardLogix� 5580 controllers CompactLogixTM 5380 and Compact GuardLogix 5380 controllers ControlLogix 5570 and GuardLogix 5570 controllers CompactLogix 5370 and Compact GuardLogix 5370 controllers

EtherNet/IP Network
� An EtherNet/IP network supports messaging, produced and consumed tags, and distributed I/O.
� An EtherNet/IP network with 5570 or earlier, and 5370 or earlier controllers supports half-duplex/full-duplex, 10 Mbps or 100 Mbps operation.
� An EtherNet/IP network with 5580 or 5380 controllers supports full-duplex, 10/100/ 1000 Mbps operation.
� An EtherNet/IP network requires no network scheduling. � There are several methods available to configure EtherNet/IP network parameters for
devices. Not all methods are always available. These methods are device and configuration dependent: � DHCP � Rockwell Automation� BOOTP/DHCP utility � Programming software � Studio 5000 Logix Designer� application � RSNetWorxTM for EtherNet/IP software � Web browser � SNMP tools
Application Ideas � Connectivity to commercial devices (such as cameras and phones) � Business systems with remote access or sharing data � Applications with motion or safety on the same network. � Plant management (material handling) � Configuration, data collection, and control on a high-speed network � Time-critical applications with no established schedule � Inclusion of commercial technologies (such as video over IP) � Internet/Intranet connection

Example Topologies Star
Ring with Switches
Linear
Device Level Ring (DLR)

Parallel Redundancy Protocol (PRP)

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Guidelines for EtherNet/IP Networks

Guideline Use these publications. Data transmission depends on the controller.
You can add I/O modules at runtime. Data transmission rate depends on the RPI.
Select unicast EtherNet/IP communication whenever possible.

Description
� EtherNet/IP Network Devices User Manual ENET-UM006A-EN-P, publication ENET-UM006 � EtherNet/IP Device Level Ring Application Technique, publication ENET-AT007 � EtherNet/IP Design Considerations Reference Manual, publication ENET-RM002
The type of controller determines the data transmission rate. � ControlLogix controllers transmit data at the RPI you configure for the module. � CompactLogix controllers transmit data at powers of 2 ms (such as 2, 4, 8, 16, 64, or 128). For example, if you
specify an RPI of 100 ms, the data actually transfers at 64 ms.
You can add I/O modules to remote chassis connected via an EtherNet/IP network to a running controller. You can configure direct or rack-optimized connections. For more information, see Runtime/Online Addition of Modules on page 98.
An EtherNet/IP network broadcasts I/O information to the controller based on the RPI setting. With change of state (COS) enabled and: � No data changes, the EtherNet/IP module produces data every RPI. � Data changes, the EtherNet/IP module produces data at a maximum rate of RPI/4.
To reduce bandwidth use and preserve network integrity, some facilities block multicast Ethernet packets. Multicast is a more efficient method for transmitting data with multiple consumers and redundancy applications. You can configure multicast or unicast connections for: � Produced and consumed tags by using the Logix Designer application � I/O modules by using the Logix Designer application. Unicast connections help with the following: � Let produced and consumed tag communication span multiple subnets � Reduce network bandwidth. � Simplify configuration for EtherNet/IP network devices because of unicast default setting for the Logix Designer
application.

ControlNet Network Topology

ControlNet Network

Topology

� A ControlNet network lets both I/O and messaging on the same wire. � Multiple controllers and their respective I/O can also be placed on the same
ControlNet wire. � When new I/O is added, or when the communication structure on an existing I/O module changes,
you must use RSNetWorx for ControlNet software to reschedule the network. � If the network timing changes, every device with scheduled traffic on the network
is affected. � To reduce the impact of changes, place each CPU and its respective I/O on isolated ControlNet
networks. � Place shared I/O and produced/consumed tags on a common network available to each CPU that
needs the information. � Built-in redundant cabling supports I/O network and provides HMI switchover in redundant
ControlLogix system.
Application Ideas � Default Logix network � Best replacement for universal remote I/O � Backbone to multiple distributed DeviceNet networks � Peer interlocking network � Common devices include: Logix 5000TM controllers, PanelViewTM terminals, I/O modules, and drives

ControlNet Network ControlNet Network

Shared I/ O
ControlNet Network

CPU

CPU

I/O

I/O

I/O

I/O

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Guidelines for ControlNet Networks

Guideline Use these publications. Adjust the default RSNetWorx for ControlNet settings.
Design for at least 400 KB of available, unscheduled network bandwidth, as displayed by RSNetWorx for ControlNet software. Place DeviceNet (1756-DNB) communication modules in the local chassis.
Limit 1756-CNB, 1756-CNBR connections.
For additional connections, consider the 1756-CN2, 1756-CN2R, 1756-CN2RXT modules. If you change network settings, resave each controller project. You can add I/O modules at runtime. Data transmission depends on the controller.

Description
� ControlNet Coax Media Planning and Installation Guide, publication CNET-IN002 � ControlNet Fiber Media Planning and Installation Guide, publication CNET-IN001 � ControlNet Network Configuration User Manual, publication CNET-UM001
Change these settings in the RSNetWorx for ControlNet software: � UMAX (highest unscheduled node on the network)
� Default is 99 � The network takes the time to process the total number of nodes that are specified in this setting, even if there
are not that many devices on the network � Change to a reasonable level to accommodate the active network devices and additional devices that can be
connected � SMAX (highest scheduled node on the network)
� Default is 1 � This must be changed for all systems � Set SMAX < UMAX
Leaving too little bandwidth for unscheduled network communication results in poor message throughput and slower workstation response. Unscheduled data transfers on ControlNet occur asynchronous to the program scan and support a maximum of 510 bytes/node per ControlNet NUT.
DeviceNet (1756-DNB) communication modules have multiple, 500-byte data packets that impact scheduled bandwidth. Place these modules in the same chassis as the controller to avoid this data being scheduled over the DeviceNet network. If you must place these communication devices in remote chassis, configure the input and output sizes to match the data that is configured in RSNetWorx for DeviceNet software. This reduces the amount of data that must be transmitted.
For best performance, limit the 1756-CNB, 1756-CNBR to 40...48 connections. Add additional 1756-CNB, 1756-CNBR modules in the same chassis if you need more connections. To improve system performance, you can add more modules and split connections among the modules. If the chassis that contains the CNB module also contains multiple digital I/O modules, configure the CNB communication format for Rack Optimization. Otherwise, use None. As a cost savings measure, use 1756-CNB, 1756-CNBR modules in chassis that contain only I/O modules for traditional adapter functionality. Use the 1756-CN2, 1756-CN2R, 1756-CN2RXT modules in the same chassis as the controller for traditional scanner functionality.
The 1756-CN2/B, 1756-CN2R/B, 1756-CN2RTXT communication modules each support 131 connections, and have higher performance than previous modules. The 1756-CN2/A, 1756-CN2R/A communication modules each support 100 connections.
Any time that you edit the network with RSNetWorx for ControlNet software and you save or merge your edits, connect to each controller in the system with their respective project file and perform a save and upload. This copies the ControlNet settings into the offline, database file and makes sure that future downloads of the controller permit it to go online without having to run RSNetWorx for ControlNet software.
You can add 1756 I/O modules and some drives to remote chassis connected via ControlNet to a running controller. It is recommended to use a 1756-CN2/B, 1756-CNB2R/B, or 1756-CN2RXT module as the traditional scanner in these applications.
The type of controller determines the data transmission rate. � ControlLogix controllers transmit data at the RPI you configure for the module. � CompactLogix controllers transmit data at powers of 2 ms (such as 2, 4, 8, 16, 64, and 128). For example, if you
specify an RPI of 100 ms, the data actually transfers at 64 ms.

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Guidelines for Unscheduled ControlNet Networks

Guideline

Description

You can run an entire ControlNet network as unscheduled. An unscheduled ControlNet network:
� provides for easier network configuration. � is useful if your I/O updates needs are slower. � supports the addition of 1756 I/O modules and some drives without placing the controller in Program mode. � provides an HMI network with fast switchover times in a redundant controller system.
You must still run RSNetWorx for ControlNet software at least once to configure NUT, SMAX, UMAX, and media configuration settings.

Plan appropriately if you place I/O on an unscheduled ControlNet network.

Follows these recommendations for I/O on an unscheduled ControlNet network:
� A 1756-CN2, 1756-CN2R Series B or later, or a 1756-CN2RXT is recommended. � Disable the Change of State (COS) feature on digital input modules because it can cause inputs to be sent faster
than the RPI. � Set the real-time sample (RTS) on analog cards slower than the RPI � Dedicate a ControlNet network to I/O only. � Do not exceed 80% utilization of a 1756-CN2, 1756-CN2R, 1756-CN2RXT communication module. � Do not exceed 75% utilization of a 1756-CNB, 1756-CNBR communication module. � Have no more than 48 connections on the 1756-CNB, 1756-CNBR communication module. � Use a NUT of 10 ms or more. � Keep the SMAX and UMAX values as small as possible.

1756-CNB, 1756-CNBR only Set the RPI at 25 ms or slower.

Use RPI of 25 ms or slower for unscheduled modules to avoid overload on the 1756-CNB, 1756-CNBR communication module. Depending on the RPI, the communication module loading increases 1...4% for each I/O module added.
Additional 1756-CNB, 1756-CNBR Loading

Additional CNB Loading %

1756-CNB, 1756-CNBR only The RPI affects how many I/O modules you can have.

RPI (ms)
This chart shows the number of modules and associated RPIs so that you do not exceed 75% utilization of the 1756-CNB, 1756-CNBR communication module.
Maximum Number of I/O Modules in an Unscheduled Network

Number of Unscheduled Modules

RPI (ms)

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Compare Scheduled and Unscheduled ControlNet Communication

Scheduled ControlNet Communication

Unscheduled ControlNet Communication

Deterministic

Less deterministic than scheduled communication Provides simpler ControlNet installations when scheduled networks are not required

To add scheduled I/O on the ControlNet network, you must: � Add the I/O to an offline controller project. � Download the project to the controller. � Run RSNetWorx to schedule the network requires network to be scheduled (must stop
the network and put the controller in Program mode to schedule a network). � Save the controller project.

Can be changed online without impacting the schedule New modules can affect other modules communicating via unscheduled bandwidth Supports 1756 I/O modules and some drives

RPI and NUT determine module communication rates

RPI determines module communication rates

MSG and HMI traffic can occur on the same network because they are isolated in unscheduled traffic
MSG and HMI traffic do not affect I/O communication

Recommend 1756-CN2, 1756-CN2R, 1756-CN2RXT Recommend a dedicate ControlNet network for only I/O modules MSG and HMI traffic can affect I/O communication

Direct and rack-optimized connections to I/O

Only direct connections to I/O (results in being able to use fewer total I/O modules because of the connection limits of controllers and communication modules)

Supports any firmware revision of a ControlNet communication module

You can use any 1756-CN2, 1756-CN2R, 1756-CN2RXT communication module If you use a 1756-CNB, 1756-CNBR communication module, it must be series D or later

Supports any I/O platform that can communicate via a ControlNet network

Supports only 1756 I/O modules

DeviceNet Network Topology

DeviceNet Network

Topology

� You need a DeviceNet scanner to connect the controller to DeviceNet devices.
� You must use RSNetWorx for DeviceNet software to configure devices and create the scanlist for the scanner.
� You can configure the network communication rate as 125 Kbps (default and a good starting point), 250 Kbps, or 500 Kbps.
� If each device on the network (except the scanner) sends  4 bytes of input data and receives  4 bytes of output data, you can use AutoScan to configure the network.
Application Ideas � Distributed devices � Drives network � Diagnostic information

Single Network

CPU Scanner

Device

Device

Several Smaller Distributed Networks (Subnets)

CPU

Linking

Device

Device

Device

Linking Device

Device

Device

Device

Device

Device

Device

Device

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Guidelines for DeviceNet Networks

Guideline

Description

Use these publications.

� DeviceNet Cable System Manual, publication DNET-UM072 � DeviceNet Network Configuration User Manual, publication DNET-UM004

Use the DeviceNet Tag Generator tool.

The Logix Designer application includes a DeviceNet tag generator tool that creates device-specific structured tags and logic based on the network configuration in RSNetWorx for DeviceNet software.
The logic copies data to and from the DNB data array tags to the device tags so that data is presented synchronously to program scan.

Place DeviceNet (DNB) communication modules in the local chassis.

Place DNB modules in the local chassis to help maximize performance, especially in ControlLogix systems.
Size the input and output image for the DNB modules to the actual devices that are connected plus 20% for future growth. If you have to place DNB modules in remote chassis, sizing the input and output images is critical for best performance.

Verify that the total network data does not exceed the maximum DNB data table size.

A DNB supports: � 124, 32-bit input words. � 123, 32-bit output words. � 32, 32-bit status words.
You can use RSNetWorx for DeviceNet software offline to estimate network data. Use a second DNB if there is more network data than one module can support.

Configure slaves first.

Configure device parameters before adding that device to the scanlist. You cannot change the configuration of many devices once they are already in the scanlist.
If you configure the scanner first, there is a chance that the scanner configuration cannot match the current configuration for a device. If the configuration does not match, the device does not show up when you browse the network.

Leave node address 63 open to add nodes.

Devices default to node 63 out-of-the-box. Leave node address 63 unused so you can add a new device to the network. Then change the address of the new device.

Leave node address 62 open to connect a computer. Always leave at least one open node number to let a computer be attached to the network if needed for troubleshooting or configuration.

Don't forget to set the scanner run bit.

For the scanner to be in Run mode, the controller must be in Run mode and the logic in the controller must set the scanner run bit.

Make sure that you have the most current EDS files for RSNetWorx for DeviceNet software uses EDS file to recognize devices. If the software is not properly recognizing a device,

your devices.

you are missing the correct EDS files. For some devices, you can create an EDS file by uploading information from the

device. Or you can get EDS files from: http://www.ab.com/networks/eds.

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Communicate with Other Devices

The MSG instruction asynchronously reads or writes a block of data to another device.

If the target device is a Logix 5000TM controller I/O module that you configure with the Studio 5000 Logix Designer� application SERCOS drive PLC-5� controller
SLCTM controller MicroLogixTM controller Block transfer module PLC-3� processor
PLC-2� processor

Select one of these message types CIPTM Data Table Read CIP Data Table Write Module Reconfigure CIP Generic SERCOS IDN Read SERCOS IDN Write PLC5 Typed Read PLC5 Typed Write PLC5 Word Range Read PLC5 Word Range Write SLC Typed Read SLC Typed Write Block Transfer Read Block Transfer Write PLC3 typed read PLC3 typed write PLC3 word range read PLC3 word range write PLC2 unprotected read PLC2 unprotected write

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Cache Messages

Some types of messages use a connection to send or receive data. Some also give you the option to either leave the connection open (cache) or close the connection when the message is done transmitting. This table shows messages that use a connection and whether you can cache the connection.

Message Type

Communication Method

Uses Connection Can Cache Connection

CIP data table read or write

CIP

Yes

Yes

PLC2, PLC3, PLC5, or SLC (all types) CIP

CIP with Source ID

CIP generic

DH+TM N/A

Yes Your option(1)

Yes Your option(1)

Block transfer read or write

N/A

Yes

Yes

(1) You can connect CIP generic messages, but for most applications we recommend that you leave CIP generic messages unconnected.

A cached connection remains open until one of the following occurs: � The controller goes to Program mode. � You rerun the message as uncached. � Another message is initiated and a cached buffer is needed. � An intermediate node in the connection goes down.

Message Buffers
MSG and Block Transfer Instructions
Communication Handler
Data To and From the Controller

The controller has buffers for unconnected messages and for cached messages. Buffers store incoming and outgoing message data until the controller can process the data.

Unconnected Buffers Incoming
Outgoing

Open/Close Connections CIP Generic MSG Unconnected MSG

Controller Connections
Connections (Buffers)

Uncached Connected CIP MSG or Block Transfer

Cache Buffers MSG Buffers BT Buffers

Cached Connected MSG or Block Transfer

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Buffer Outgoing, connected
Incoming,unconnected
Cached buffers
Buffers 1...10 11 12...40

Communicate with Other Devices Chapter 11
Description
The outgoing unconnected buffers are for: � Establishing I/O connections to local I/O modules and remote devices on ControlNet�, EtherNet/IPTM, and
remote I/O networks. � Executing unconnected PLC2, PLC3, PLC5, or SLC (all types) messages over Ethernet/IP or ControlNet
(CIP and CIP with Source ID) networks. � Initiation of messaging over a DH+TM network (uses 2 buffers, one to open the connection and one to transfer
data). � Initiation of uncached block transfers. � Initiation of uncached CIP read/write message instructions. � Initiation of cached block transfers. � Initiation of cached CIP read/write messages instructions. � CIP Generic message instructions.
The incoming unconnected buffers: � Initially receive a cached CIP message instruction. � Receive an uncached CIP message instruction. � Receive a message over a DH+ network. � Receive a CIP Generic message instruction. � Receive a read or write request from a ControlNet PanelViewTM terminal (unconnected messaging). � Initially receive of a read request from an EtherNet/IP PanelView terminal (connected messaging). � Receive a write request from an EtherNet/IP PanelView terminal (unconnected messaging). � Receive an initial request from the Logix Designer application to go online. � Initially receive Linx-based connections.
The cached buffers are outgoing buffers for messages and block transfers. A cached connection helps message performance because the connection is left open and does not need to be re-established the next time that it is executed. A cached connection counts towards the total limit of connections for a controller. A cached connection is refreshed at the connection RPI. All cached entries are closed when the controller transitions to Program mode. The first time a cached message is executed, it uses one of the outgoing unconnected buffers. When the connection is established, it moves into the cached buffer area. For optimum performance, do not cache more messages or block transfers than there are cached buffers. If you cache more than the available cached buffers, the controller looks for a connection that has been inactive for the longest time, closes that connection, and lets a new connection take its place. The controller closes a cached message or block transfer, depending on which has been inactive the longest. If all cached connections are in use, the message is executed as connected and, once it is completed, the connection is closed. You can multiplex cached connections. If a connection is inactive and a message instruction executes that has the same target and path, it uses that inactive connection. For example, if you have a block transfer read and write to the same module, interlock the read and write so that only one is active at a time. Then when they are cached, they use the same cached connection.
Outgoing Unconnected Buffers
IMPORTANT This section does not apply to 5380, 5480, or 5580 controllers.
Use
The first 10 buffers (default) are shared for unconnected messaging, initiating connected messaging, establishing I/O connections, and establishing produced/consumed connections.
The 11th buffer is dedicated to establishing I/O and produced/consumed connections.
The 12th to the 40th buffers are used only for initiating connected messages and executing unconnected messages. To increase the outgoing buffers to a value higher than 11, execute a CIP generic message to configure that change each time you transition from Program mode to Run mode.

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Guidelines for Messages

Guideline Message tags may be created at controller scope or program scope. You can use a message to send a large amount of data.
Do not manipulate the message status bit

Description
The operating system accesses the information in a message tag asynchronously to the program scan. Along with the visible fields within the message tag, there are hidden attributes that are only referenced by the background operating system.
Even though there are network packet limitations (such as 500 bytes on ControlNet and 244 bytes on DH+), the controller can send a large amount of data from one MSG instruction. When configuring the message, select an array as the source/destination tags and select the number of elements (as many as 32,767 elements) you want to send. The controller automatically breaks the array into small fragments and sends all of the fragments to the destination. On the receiving side, the data appears in fragments, so some application code can be required to detect the arrival of the last piece.
Do not change the following status bits of a MSG instruction: � DN � EN � ER � EW � ST
Do not change those bits either by themselves or as part of the FLAGS word. If you do, the controller can have a nonrecoverable fault. The controller clears the project from its memory when it has a nonrecoverable fault.

Guidelines to Manage Message Connections

Guideline Create user-defined structures or arrays.
Cache connections when appropriate.

Description
User-defined structures let you organize your data to match your machine or process. � One tag contains all data that is related to a specific aspect of your system. This keeps related data together and easy
to locate, regardless of its data type. � Each individual piece of data (member) gets a descriptive name. This automatically creates an initial level of
documentation for your logic. � You can use the structure to create multiple tags with the same data layout. � Linx-based software can optimize user-defined structures more than standalone tags.
If a message executes repeatedly, cache the connection. This keeps the connection open and optimizes execution time. You can increase execution time if you open a connection each time the message executes. If a message executes infrequently, do not cache the connection. This closes the connection upon completion of the message, which frees up that connection for other uses.

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Guidelines for Block Transfer Messages

Guideline

Description

Distribute 1771 analog modules across multiple chassis. To reduce the number of block transfers that one 1771-ACN or 1771-ASB module manages, distribute 1771 analog modules across multiple chassis.

Isolate different 1771 chassis on different networks.

When you isolate different chassis onto different networks, it diversifies the communication so that no single network or communication module has to deal with all communication.

Increase ControlNet unscheduled bandwidth.

If you communicate over a ControlNet network, increase the amount of ControlNet unscheduled bandwidth to permit additional time on the network for data exchange.
See Compare Scheduled and Unscheduled ControlNet Communication on page 106 for more information about unscheduled bandwidth on a ControlNet network.

Increase the system overhead timeslice percentage on Increase the system overhead timeslice to allocate more CPU time to communication processing from the continuous ControlLogix� 5570 or earlier and CompactLogixTM 5370 or task. earlier controllers.

Interlock block transfer read and write messages to the Programmatically interlock block transfer read and write messages to the same module so that both operations

same module.

cannot be active simultaneously.

Use the 1756-RIO module for systems with a high number The 1756-RIO module provides connectivity from a ControlLogix chassis to 1771 I/O and other modules that are

of block transfer modules.

connected via remote I/O. The 1756-RIO module off-loads the burden of performing block transfers from the

controller and increases the number of block transfer operations that can be performed.

Map Tags

A Logix 5000TM controller stores tag names on the controller so that other devices can read or write data without having to know physical memory locations. Many products only understand PLC/SLC data tables, so the Logix 5000 controller offers a PLC/SLC mapping function that lets you map Logix tag names to memory locations.
� You only have to map the file numbers that are used in messages; the other file numbers do not need to be mapped.
� The mapping table is loaded into the controller and is used whenever a logical address accesses data.
� You can only access controller-scoped tags (global data).

Follow these guidelines when you map tags.
� Do not use file numbers 0, 1, and 2. These files are reserved for Output, Input, and Status files in a PLC-5 processor.
� Use PLC-5 mapping only for tag arrays of data type INT, DINT, or REAL. Attempting to map elements of system structures can produce undesirable effects.
� Use these file types and identifiers.

For this Logix 5000 array type INT array DINT array REAL array

Use this PLC file identifier N or B L F

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12 Chapter

Alarm Option FactoryTalk� Alarms and Events
Controller tag-based alarms Controller instruction-based alarms

The following options are available for alarms:
Description
The FactoryTalk Alarms and Events system integrates alarming between FactoryTalk View SE applications and the controllers by embedding an alarming engine in the controllers. � Uniform, micro-second accurate, time stamps determined at the alarm source � Server-client model so all clients get the updates simultaneously � Single connection to controller � Combines all alarms in the system into one uniform view � Supports ControlLogix�, CompactLogixTM, SLCTM, PLC-5�, and non-Rockwell Automation controller For more information, see FactoryTalk Alarms and Events Configuration Guide, FTAE-RM001.
Tag-based alarms monitor a tag value to determine the alarm condition. Tag-based alarms are not part of the logic program and do not increase the scan time for a project. � Alarms defined on tags with periodic evaluation � Standards-based design � Leverages existing FactoryTalk Alarms and Events infrastructure Only 5380 and 5580 controllers support tag-based alarms.
Instruction-based alarms are generated and maintained by using an instruction in a Logix controller. Two Logix-based alarm instructions that are available in relay ladder, structured text, and function block diagram. � The Digital Alarm (ALMD) instruction detects alarms that are based on Boolean (true/false) conditions. � The Analog Alarm (ALMA) instruction detects alarms that are based on the level or rate of change of analog values. Alarm instructions and their specific data types consume a larger portion of controller memory and scan time than tagbased alarms. � Alarms are detected at the same time logic is executed � Alarms events are buffered in controller memory � Alarms events are pushed to the HMI only on state changes

Guidelines for Tag-Based Alarms
Guideline An alarm definition is associated with an Add-On Instruction (AOI) or a defined data type.
Use the keyword THIS to create modular logic to access alarm attributes Access individual alarm attributes

Tag-based alarms are useful when you want to maximize controller scan time and when you want to integrate alarms with legacy or third-party devices.
Description
When a tag is created using a data type or an AOI that has alarm definitions, alarms are created automatically based on the alarm definitions. You can create an alarm definition for the following components: � Tag or parameter of an AOI. � Member of a user-defined data type (UDT) � Member of a system-defined data type � Member of a module-defined data type When a tag uses a data type that has alarm definitions that are associated with it, alarm conditions are automatically added for the tag based on its alarm definitions. When an AOI is based on an AOI definition, alarm conditions are automatically added for the AOI instance based on the alarm definitions that are associated with the AOI definition.
When the logic executes, the controller replaces THIS with the name of a program, controller, or Add-On Instruction. The keyword THIS lets you create a logic module that can be inserted in any project on any controller and still execute correctly. Use ::THIS to represent a controller name, \THIS to represent a program name, and THIS to represent the name of an Add-On Instruction.
Use tag-based alarm attributes as operands in instructions to access tag-based alarm attributes or attributes from a set of alarms. For example, the alarm set for a controller, program, or for instances of an Add-On Instruction.

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Guideline
Access alarm set attributes
Access individual alarm attributes in Add-On Instruction definitions
Access attributes from Add-On Instruction alarm sets

Description
Use alarm set attributes as operands in instructions to access the attributes.
Use individual alarm attributes as operands in Add-On Instruction (AOI) definitions to access the attributes of alarms that are associated with local tags, input parameters, or output parameters within the same AOI instance.
The alarms contained in an Add-On Instruction (AOI) definition, a structured tag of an AOI definition, or an array tag of an AOI definition can be referenced as an alarm set. Use these alarm set attributes as operands in logic. When you reference an attribute from an individual alarm, you insert the owner of the alarm in the operand syntax. Similarly, when you reference an attribute from an AOI alarm set, you insert the alarm set container (the AOI definition, AOI structured tag, or AOI array tag) in the operand syntax.

Access Tag-based Alarms
Instructions can access the members of the following tag-based alarms: � Alarm conditions that are associated with controller tags. � Alarm conditions that are associated with local scalar tags, input parameters, output parameters, or public parameters within the same program. � Alarm conditions that are associated with input, output, or public parameters of other programs. � Alarm definitions that are associated with local tags, input parameters, or output parameters of an Add-On Instruction. � Alarm definitions that are associated with local tags, input parameters, or output parameters of nested Add-On Instructions.
Instructions can access the following alarm sets or members of alarm sets: � Alarm sets that are associated with the controller or with a program. � Alarm sets that are associated with controller tags. � Alarm sets that are associated with local tags, input parameters, output parameters, or public parameters within the same program. � Alarm sets that are associated with local tags, input parameters, output parameters, or public parameters of other programs. � Alarm sets that are associated with input, output, or public parameters in other programs. � Alarm sets that are associated with local tags, input parameters, or output parameters of an Add-On Instruction. � An alarm condition or an alarm set of an input, output, or public parameter in another program. � Alarm sets that are associated with local tags, input parameters, or output parameters of nested Add-On Instructions.
Instruction cannot access the members of the following tag-based alarms: � Alarm conditions that are associated with local tags in other programs. � Alarm definitions that are associated with the parent Add-On Instruction. � Alarm definitions that are associated with tags or parameters of the parent Add-On Instruction.

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Instruction cannot access the members of the following alarm sets: � Alarm sets that are associated with local tags in other programs. � Alarm sets that are associated with the parent Add-On Instruction. � Alarm sets that are associated with tags or parameters of the parent AddOn Instruction.
Instructions cannot access the following alarm attributes: � Evaluation period, alarm condition types, and expressions. � Time-related attributes that have LINT data types. � Attributes that have STRING data types. � Reference type attributes, such as associate tags, target tags, and input tags.

Guidelines for InstructionBased Alarms

Instruction-based alarms are useful when you want timestamps on alarm or you want to integrate alarms without modifying the HMI displays.

Guideline

Description

Estimate increased controller memory use for each alarm.

The alarm instructions use new alarm data types that contain state information and time stamps for each alarm. Estimate this memory use in the controller: � 2 KB per FactoryTalk Alarms and Events subscriber that receives alarms from the controller � There is a maximum of 16 subscribers per controller. Most applications only require one subscriber to a controller
to provide data to many FactoryTalk View SE clients. � 2.2 KB per alarm (typical), depends on use of associated tags

Alarm instructions increase total controller scan time.

The ALMD instructions and ALMA instructions affect total scan time. See Logix 5000TM Controllers Instruction Execution Time and Memory Use Reference Manual, publication 1756-RM087 for execution times for your controller firmware.
An alarm state change is any event that changes the condition of the alarm, such as acknowledgment or suppression of the alarm. Creating dependencies on related alarms to minimize the potential for many alarms to change state simultaneously (alarm bursts). Large alarm bursts can have a significant impact on application code scan time.
Important: In redundancy systems, consider scan time impact due to crossloading alarm tag data. For more information see the ControlLogix Enhanced Redundancy System User Manual, publication 1756-UM535.

You can edit or add an alarm instruction online.

Online edits of new and existing alarms are automatically sent to the subscribers. You do not have to re-subscribe to receive the updated information. Online changes automatically propagate from the controller alarm structure to the rest of the architecture.

In relay ladder, how you define the alarm values on the instruction determines whether you can access those values programmatically through the alarm structure.

When you create an alarm instruction, you also create an alarm data type for that alarm. For example, MyDigitalAlarm of data type DigitalAlarm. In relay ladder, the following values are shown on the instruction: � ProgAck � ProgReset � ProgDisable � ProgEnable
If you enter a value or assign a tag to these faceplate parameters (such as AckSection1All), the value or tag value is automatically written to the alarm structure each time the instruction is scanned.
If you want to programmatically access the alarm structure, you must assign the structure tag to the faceplate. For example, to use MyAnalogAlarm.ProgAck in logic, assign the tag MyAnalogAlarm.ProgAck on the faceplate to the ProgAck parameter.

Test alarm behavior from within the Logix Designer application.

On the Status tab of the alarm dialog, monitor the alarm condition, acknowledge an alarm, disable an alarm, suppress an alarm, or reset an alarm. Use the dialog selections to see how an alarm behaves, without needing an operational HMI.

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Guideline

Description

Reduce mistakes by making sure that alarms are noticed.

Shelving an alarm removes the alarm from the operator view for a period of time. It is like suppressing an alarm, except that shelving is time-limited. If an alarm is acknowledged while it is shelved, it remains acknowledged even if it becomes active again. It becomes unacknowledged when the shelve duration ends provided the alarm is still active at that moment.

Increase productivity by eliminating nuisance alarms.

Set a duration (ms) on the ALMA instruction to specify how long an alarm condition must exist before being reported. Apply the duration to individual, analog alarm levels.

High availability of alarm data helps reduce material losses.

Previous to revision 31, the alarm log in the controller stores the last 10,000 alarm state transitions in a circular log. This replaces the alarm buffer in controllers with firmware earlier than revision 21.

Configure Logix-based Alarm Instructions

Option Message string
Associated tags Severity Alarm class
View command Defaults

Description
The message string (maximum of 255 characters, including embedded text) contains the information to display to the operator regarding the alarm. Besides entering text, you can also embed variable information. In the alarm message editor, select the variable that you want and add it anywhere in the message string. You cannot programmatically access the alarm message string from the alarm tag. To change the alarm message based on specific events, configure one of the associated tags as a string data type and embed that associated tag in the message. You can maintain alarm messages in multiple languages. Either enter the different languages in the associated language versions of the Logix Designer application or in an import/export (.CSV or .TXT) file.
You can select as many as four additional tags from the controller project to associate with the alarm. These tags are sent with an alarm message to the alarm server. Associated tags can be BOOL, INT, SINT, DINT, REAL, or string data types. For example, a digital alarm for a pressure relief valve can also include information such as pump speed and system pressure, and tank temperature. Optionally, embed the associated tags into the message text string.
Use the configurable severity range from 1...1000 to rank the importance of an alarm. A severity of 1 is for low-priority alarms; a severity of 1000 is for an emergency condition. You can configure how the FactoryTalk ranges are presented to the operator. The operator can also filter on alarm levels. For example, a maintenance engineer can filter to see only those alarms at severity 128.
Use the alarm class to group related alarms. Specify the alarm class the same for each alarm you want in the same class. The alarm class is case-sensitive. For example, specify class Control Loop to group all alarms for PID loops. You can then display and filter alarms at the HMI based on the class. For example, an operator can display all tank alarms or all PID loop alarms. The alarm class does not replace subscription to specific alarms. The FactoryTalk View SE Alarm object graphics have configuration options to determine which controller alarms an operator sees.
Execute a command on the operator station when requested by an operator for a specific alarm. This lets an operator execute any standard FactoryTalk View command, such as call specific faceplates and displays, execute macros, access help files, and launch external applications. When the alarm condition occurs and is displayed to the operator, a button on the summary and banner displays lets the operator run an associated view command.
The Parameters tab of the alarm instruction properties lets you define values for instruction parameters. You can return the parameters to factory defaults and you can define your own set of instruction defaults. The instruction defaults you assign are defaults for only that instance of the instruction.

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Automatic Diagnostics

Alarms Chapter 12
Automatic Diagnostics provide device diagnostics to HMIs and other clients, with zero programming. You need:
� ControlLogix 5580, GuardLogix 5580, CompactLogix 5380, Compact GuardLogix 5380, or CompactLogix 5480 controller with firmware revision 33 or later.
� FactoryTalk View SE version 12 or later to add the Automatic Diagnostic object to FactoryTalk View displays. See the FactoryTalk View Site Edition User's Guide, publication VIEWSE-UM006.
� FactoryTalk Alarms and Events version 6.20 or later to subscribe to the diagnostic messages created in the controller. See the FactoryTalk Alarms and Events System Configuration Guide, publication FTAE-RM001.
The diagnostics include device description conditions and state events. Diagnostics based on the device definition (such as fault or open wire) are sent to a compatible Rockwell Automation HMI device or software, and displayed on the Automatic Diagnostic Event Summary object.

Automatic Diagnostics is enabled by default with firmware revision 33.00 or later. You can disable and enable the whole feature while online or offline from the Controller Properties dialog box. You can also disable Automatic Diagnostics for a specific device in the device's configuration.
When Automatic Diagnostics is enabled, there is little impact to device and network performance.

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Notes:

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13 Chapter
Optimize an Application for Use with HMI

Rockwell Automation offers these HMI (human machine interface) platforms.

Platform PanelViewTM 5000 terminal PanelView Plus terminal FactoryTalk� View software

Description
Dedicated, machine-level HMI running Studio 5000 View Designer� software
Dedicated, machine-level HMI running FactoryTalk� View Machine Edition software
Product family that consists of: � FactoryTalk View ME (Machine Edition) software for an open, machine-level HMI; also runs on PanelView Plus terminals � FactoryTalk View Site Edition Station software for a single-workstation, supervisory-level HMI � FactoryTalk View Site Edition distributed software for a multi-server, multi-client, supervisory-level HMI"

Software products that provide plant-floor device connectivity for HMI applications include:
� RSLinx� Classic software � FactoryTalk Linx software (formerly RSLinx Enterprise)

Linx-based Software Use of The amount of memory that Linx-based software needs depends on the type of

Controller Memory

data Linx-based software reads. These equations provide a memory estimate.

IMPORTANT This topic does not apply to 5380, 5480, or 5580 controllers.

Linx-based software overhead (per _____ * 1345 = ___ bytes (four connections by default) connection)

Individual tags

_____ * 45 = ___ bytes

Arrays / structures

_____ * 7 = ___ bytes

Total = ___ bytes

You can consolidate tags into an array or a structure to reduce the communication overhead and the number of connections that are used to obtain the data.

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HMI Implementation Options

Method Single HMI Multiple, Independent HMI
Client/Server HMI

Benefits

Considerations

� All HMI/EOI support this method � Limited number of controller connections � No server to configure and manage � Local control and monitoring

� Single point of failure for visualization � Only one person can monitor one display at a time

� All HMI/EOI support this method � The same HMI screens can be viewed at multiple stations � Multiple people can monitor different parts of system
simultaneously � Each HMI gets its own data � No central server to configure and manage � Local control and monitoring

� More controller connections are required � Additional burden on controller to service all communication
(controller resource impact) � No sharing of data except through the controller � Adding additional HMIs has larger increase on system

� The same HMI screens can be viewed at multiple stations � Server provides data to multiple clients � Fewer controller connections required � Impact on system is smaller than with multiple HMIs � Administer application at the server, not individually at the clients
or multiple, independent HMIs

� Server is a point of failure for all HMIs, unless you implement redundancy
� Little communication overhead savings if each client wants different data
� Networking knowledge that is required

Most third-party HMIs are limited to direct communication similar to the multiple HMI method.

Guidelines for FactoryTalk View Software

For the latest information on guidelines for FactoryTalk View Site Edition Software, see the Rockwell Automation� Knowledgebase ID 32549 titled FactoryTalk View SE Distributed System Design Considerations.

How a Data Server Communicates with the Controllers

Linx-based software acts as a data server to optimize communication to HMI applications. Linx-based software groups data items into one network packet to reduce:
� The number of messages that are sent over the network. � The number of messages a controller processes.
1. When Linx-based software first connects to a controller, it queries the tag database and uploads definitions for all controller-scoped tags. If there are multi-layer, user-defined structures that are controller-scoped, Linx-based software just queries the upper layer.
2. When the HMI client requests data, Linx-based software queries the definitions for program-scoped tags and the lower layers of multi-layer user-defined structures.
3. Linx-based software receives requests for data items from local or remote HMI/EOI clients and combines multiple requests in optimized packets. Each data item is a simple Logix tag, array, or user-defined structure. Each optimized packet can be as large as 480 bytes of data and can contain one or more data items.

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Optimize an Application for Use with HMI Chapter 13
4. The controller allocates unused system memory to create an optimization buffer to contain the requested data items. � One optimization buffer can contain as much data as can fit into one 480-byte packet (optimization is limited to 480 bytes). � If you use the Logix Designer application to monitor controller RAM, you can see used memory increase. (Note that this does not apply to 5380, 5480, or 5580 controllers.) � The controller creates an optimization buffer for each Linx-based optimization packet in the scan.

Kbytes of Memory Needed

Standalone Tags Tags on Scan in Linx-based Software

Optimized Array Tags

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Compare RSLinx Classic and FactoryTalk Linx Software

Comparison

RSLinx Classic Software

FactoryTalk Linx Software(1)

Supported platforms

Microsoft� Windows operating systems. For the latest information regarding software platform support, see the Product Compatibility and Download Center: http://www.rockwellautomation.com/global/support/pcdc.page

Data server

OPC data server
Preferred data server for PLC/SLC platforms and applications that require complex network routings
Maximum 10 clients per data server

Factory Talk Live data server Preferred data server for Logix 5000TM platforms Maximum 20 clients per data server

PLC/SLC systems

Maximum 20 controllers per data server via an Ethernet network

Maximum 20 controllers per data server via an Ethernet network

Logix 5000 systems

Maximum: � 10 controllers per data server via an Ethernet network � 10,000 active (on-scan) tags per data server � Three RSLinx data servers per controller

Maximum: � 20 controllers per data server via an Ethernet network � 20,000 active (on-scan) tags per data server � Three FactoryTalk Linx data servers per controller

User interface and event logs Yes

� Available user interfaces are FactoryTalk Studio software and FactoryTalk Administration Console software
� Event logs are available with FactoryTalk Diagnostics software

Benefits

� Supports topic switching with redundant ControlLogix� system � Supports used-defined tag optimization � RSLinx Gateway software consolidates multiple HMI requests to
reduce network traffic � Works with an integrated OPC server

� Automatically handles Logix tag changes � FactoryTalk Live Data software consolidates multiple HMI requests
to reduce network traffic

Considerations

� Requires HMI to be restarted if a Logix 5000 controller is reloaded with changes to tags on scan
� Default is four connections for a read and one connection for a write

� Does not support topic switching with redundant ControlLogix system
� Optimization is limited to array tags � FactoryTalk Gateway software provides OPC support � Default is four connections for a read and one connection for a
write

(1) With version 6.00, RSLinx Enterprise is known as FactoryTalk Linx.

The Logix Designer application defaults to RSLinx Classic software. With version 31 or later, you can configure the Logix Designer application to use RSLinx Classic or FactoryTalk Linx software.

Guidelines for Linx-based Software

Guideline Use Linx-based software as the data server for multiple HMIs.
Do not use too many RSLinx stations.
Account for delay time when adding/removing scanned tags.

Description
For multiple HMI stations: � Leverage remote OPC (RSLinx Classic software) or FactoryTalk software (FactoryTalk Linx software) for
data collection. � Only the RSLinx data server is expected to have an active topic. � Do not configure or use topics on the HMI stations. � Linx-based software does not need to be on the HMI stations.
The performance of tag collection decreases as the more RSLinx stations collect data from the same controller. Use an RSLinx Gateway station and have the other data collection stations use remote OPC for data collection.
When switching from one HMI screen to another, it takes time to put items in the controller on scan and take items off scan. Part of this time delay is because the controller allocates system memory for the optimization buffer. To minimize this delay, when switching between HMI screens, put the items in the HMI screens on scan and leave them on scan. For example, you can create a data log to keep the items on scan. Then when switching between HMI screens, data collection continues without interruption. FactoryTalk Linx and FactoryTalk View Site Edition software account for this time delay. When HMI screens change, these applications deactivate tags rather than remove them from scan.

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Guidelines to Configure Controller Tags

Guideline Use INT data types with third-party products.
Group related data in arrays.
Use Linx-based OPC services.

Description
Most third-party operator interface products do not support DINT (32-bit) data types. However, there are additional performance and memory-use considerations when you use INT data types. FactoryTalk View software supports native Logix 5000 data types (including BOOL, SINT, INT, DINT, and REAL), structures, and arrays.
Most third-party operator interface products do not support user-defined structures. Arrays also make sure that data is in contiguous memory, which optimizes data transfer between the controller and Linx-based software or other operator interfaces. Arrays of tags transfer more quickly and take up less memory than groups of individual tags.
Use Linx-based OPC services to bundle multiple tag requests into one message to reduce communication overhead. OPC provides better optimization than DDE.

Logix 5000 Array Data Type BOOL SINT INT DINT LINT REAL

Reference Controller Data from FactoryTalk View Software

This table shows how to reference data in a FactoryTalk View tag address.

Description Value of 0, 1, or -1 8-bit integer 16-bit integer 32-bit integer 64-bit integer value to store date and time values Floating point

PLC File Identifier B A N L No PLC identifier F

FactoryTalk View Tag Data Type Digital Byte Integer Long Integer Not supported Floating Point

When addressing a Logix 5000 string tag, use the address syntax [OPC_Topic]StringTag.Data[0],SC82 to address a SINT array. The string data is stored in the SINT array .Data of the string tag, and you address the first element of this array (.Data[0]). The maximum number of characters in a STRING tag is 82. If you need more characters, then create your own user-defined structure to hold the characters.
To write data into a Logix 5000 string tag from an HMI or external source, set the L.EN field to indicate the number of characters that are in the string. The Logix Designer application and the controller use the .LEN value to determine how many characters are present.

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Notes:

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Develop Equipment Phases

14 Chapter

The PhaseManagerTM option of the Studio 5000 Logix Designer� application gives you a state model for your equipment. It includes the following components:
� Phase to run the state model
� Equipment phase instructions for programming the phase
� PHASE data type

Guidelines for Equipment Phases

Guideline Use a separate phase for each activity of the equipment. Complete one state model for each phase.
Separate phase code from equipment code. Separate normal execution from exceptions.
Use Equipment Phases in redundant systems.

Description
Each phase is a specific activity that the equipment performs. � Use one phase for standalone machines. � Make sure that each phase does an independent activity. � Keep the total number of phases and programs in a project within the limit of programs for the controller. � List the equipment that goes with each phase.
Each phase runs its own set of states. A state model divides the operating cycle of the equipment into a series of states. � Decide which state to use for the initial state after power-up. � Start with the initial state and work through the model. � Use only the states you need; skip those states that do not apply. � Use subroutines for producing and standby states.
The state model of an equipment phase is similar to the S88 state model. U.S. standard ISA S88.01-1995 and its IEC equivalent IEC 61512-1-1998 is commonly referred to as S88. It is a set of models, terms, and good practices for the design and operation of manufacturing systems.
One advantage of a phase is that it lets you separate the procedures (recipes) for how to make the product from the control of the equipment that makes the product. This makes it easier to execute different procedures for different products by using the same equipment.
A state model makes it much easier to separate the normal execution of your equipment from any exceptions (faults, failures, off-normal conditions). � Use a prestate routine to watch for faults. � A prestate routine is not a phase state routine. Create a routine like you do for any program and assign it as the
prestate routine for the equipment phase program. � Use a state bit to limit code to a specific state. � The Logix Designer application automatically makes a tag for each phase. The phase tag has bits that identify the
state of the phase. For example, My_Phase.Running.
PhaseManager has been tested for compatibility with ControlLogix� redundancy systems. See the ControlLogix Enhanced Redundancy System, firmware revision 16.81, Release Notes, publication 1756-RN650, for more information.

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Equipment Phase Instructions

The equipment phase instructions are available in relay ladder and structured text programming languages. You can use them in relay ladder routines, structured text routines, and SFC actions.

If you want to: Signal a phase that the state routine is complete so go to the next state. Change the state or substate of a phase. Signal a failure for a phase. Clear the failure code of a phase. Initiate communication with FactoryTalk� Batch software. Clear the NewInputParameters bit of a phase. Create breakpoints within the logic of a phase. Take ownership of a phase to either: � Prevent another program or FactoryTalk Batch software from commanding a phase. � Make sure another program or FactoryTalk Batch software does not already own a phase. Relinquish ownership of a phase. Override a command.

Use this instruction: Phase State Complete (PSC) Equipment Phase Command (PCMD) Equipment Phase Failure (PFL) Equipment Phase Clear Failure (PCLF) Equipment Phase External Request (PXRQ) Equipment Phase New Parameters (PRNP) Equipment Phase Paused (PPD) Attach to Equipment Phase (PATT)
Detach from Equipment Phase (PDET) Equipment Phase Override (POVR)

For more information, see the PhaseManager User Manual, publication LOGIX-UM001.

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Manage Firmware

15 Chapter

The controllers, I/O modules, and other devices use firmware that you can update on your own. You choose the firmware revision level and decide when to update the firmware.

Guidelines to Manage Controller Firmware

Guideline
Maintain software versions and firmware revisions at the same major revision levels.

Description
At release, a specific version of software supports the features and functions in a specific revision of firmware. To use a specific revision of firmware, you must have the corresponding software version. This combination of software and firmware is considered to be compatible. A revision number consists of a major and minor revision number in this format xx.yyy.

Where xx
yyy

Is the
Major revision Updated every release there is a functional change.
Minor revision Updated anytime there is a change that does not affect function or interface.

Use digitally signed firmware to maintain firmware Controllers support digitally signed firmware for additional security. integrity.

Document firmware revisions.

Include software version and firmware revision information in electrical drawings and other project documentation.

Read the associated release notes.

Always read the release notes that accompany new software versions and firmware revisions before you install them. The release notes help you to understand what has improved and changed, and also help you determine whether you must modify your application because of the changes. In most cases, your application runs normally following an update.

Configure modules so that the controller automatically updates firmware.

Controller firmware, revision 16, includes a Firmware Supervisor feature that lets controllers automatically update devices. To use the Firmware Supervisor: � You can update Local and remote modules while in Program or Run modes, as long as their electronic keying
configurations are set to Exact Match and the ControlFLASHTM Software supports the modules. � Firmware kits reside on the removable media in the controller.

Control that users have access to change firmware revisions.

ControlFLASH software, version 8.0 and later, is integrated with FactoryTalk� Security software so you can establish update or no update privileges for users.

Use the ControlFLASH kit manager to update only the firmware you need or have.

With ControlFLASH software, version 8.0 and later, you can: � View available firmware kits before updating a device. � Import and export kits to create custom kits. � Delete kits as single devices or as groups by catalog number and device type. � Support third-party applications to push/pull kits as needed.

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Compare Firmware Options

Controllers ship with basic firmware that supports only updating the controller firmware to the required revision. You must update the firmware to a revision that is compatible with your version of the Studio 5000 Logix Designer� application.

ControlFLASH and ControlFLASH Plus Software AutoFlash Function

Controller-based Firmware Supervisor

Standalone tool.
Manually launch from desktop icon or program list.
ControlFLASH PlusTM integrates with the Product Compatibility and Download Center and with FactoryTalk� Security software.

Integrated with the Logix Designer application.
The software automatically checks the controller, motion module, and SERCOS drive firmware during a project download. If the firmware is out of date or incompatible, the software prompts you to update the firmware.

Integrated on the controller removable media and run by the controller without user intervention.
Controllers automatically update modules on keying mismatch situations.

Supports controllers, communication modules, I/O modules, motion modules, and newer SERCOS drives, and many other devices.
ControlFLASH Plus also supports component products.

Supports the same devices as the ControlFLASHTM Software.

Supports local and remote devices that: � Are in the I/O tree and configured as Exact Match. � Support firmware updates via the ControlFLASH
Software. � The hardware revision supports the firmware that is
stored for that Exact Match device.

Supports valid CIPTM path to the device to update, such Supports valid CIP path to the device to update, such as

as serial, DeviceNet�, ControlNet�, and EtherNet/IPTM serial, DeviceNet, ControlNet, and EtherNet/IP

connections.

connections.

Supports all communication paths to devices that reside in the controller I/O tree and that also support the ControlFLASH Software.
The firmware must already be on removable media in the controller.

For more information, see these publications: � ControlFLASH Plus Quick Start Guide, publication CFP-QS001. � ControlFLASH Firmware Upgrade Software User Manual, publication 1756-UM105.

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Guidelines for the Firmware Supervisor

The Firmware Supervisor feature can automatically load firmware when you replace a device in the system.
� OEMs who build multiple machines a month can have the controller update all modules and devices in the system without user intervention.
� Machines with strict regulation can require specific firmware revisions for the devices to maintain certification. The Firmware Supervisor helps make sure that devices are at the correct firmware revision.
� Maintenance personnel replacing failed hardware can install the replacement device and the controller automatically updates the device with the correct firmware revision.

Guideline

Description

The Firmware Supervisor can update any Rockwell Automation� device that: � Can be placed in the I/O Configuration tree � Has electronic keying that is configured as Exact
Match � Normally can be updated with ControlFLASH software

The Firmware Supervisor works on local I/O modules and distributed modules via EtherNet/IP, SERCOS, and ControlNet networks. On DeviceNet networks, the Firmware Supervisor supports local devices only, such as scanners and linking devices that reside in the I/O tree of the controller project. Because you cannot directly place a remote DeviceNet device in the I/O tree, the Firmware Supervisor does not manage remote DeviceNet devices.
The Firmware Supervisor supports: � Controllers that support removable media (except for redundant controllers). � The Firmware Supervisor does not manage the firmware of other standard controllers in the I/O Configuration tree. � Safety products, including GuardLogix� Safety controllers and 1791ES CompactBlockTM Guard I/OTM EtherNet/IP
modules.
The Firmware Supervisor does not manage the firmware of POINT Guard I/OTM modules or 1791DS CompactBlock Guard I/O DeviceNet modules.
SERCOS drives that support updates over a SERCOS network: � 1394 drives, firmware revision 1.85 and later. � Kinetix� 6000 drives, firmware revision 1.85 and later. � UltraTM 3000 drives, firmware revision 1.50 and later. � 8720MC drives, firmware revision 3.85 and later.
Non-modular, distributed I/O products that sit directly on the network without an adapter. Distributed I/O products that require an adapter, such as POINT I/OTM or FLEXTM I/O modules, are not supported. Instead, the Firmware Supervisor manages the firmware for the adapters.
The Firmware Supervisor does not support PanelViewTM Plus terminals, since the terminals do not support the ControlFLASH software.

For the Firmware Supervisor to manage firmware for a device, the device must have its electronic keying that is configured for Exact Match.

Other modules can exist in the I/O Configuration that are not configured as Exact Match, but the Firmware Supervisor does not maintain the firmware for those modules. To disable the Firmware Supervisor for a specific device: Change the electronic keying for that device to something besides Exact Match. Disable Firmware Supervisor from either an SSV instruction or the Nonvolatile Memory tab of the controller properties.

Removable media must be formatted properly.

If you have a Secure Digital card with 4 GB memory or more, format the card FAT32. If you have a Secure Digital card with less than 4 GB memory, format the card FAT16.

Make sure that the removable media is not locked.

The Secure Digital card has a lock feature. The card must be unlocked to write to the card.

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Guideline

Description

For modules that are managed by the Firmware Supervisor, each controller must store the firmware files on removable media.

Enable the Firmware Supervisor, from the Nonvolatile Memory tab of the controller properties. Click Load/Store. From the Automatic Firmware Updates pull-down menu, choose Store to copy it to removable media.
The computer that runs the Logix Designer application must have: � ControlFLASH Software installed. � The required firmware kits in the ControlFLASH default directory for the modules the Firmware Supervisor is to
maintain. The Logix Designer application moves firmware kits from your computer to the removable media in the controller for the Firmware Supervisor to use. � Controller firmware and application logic are managed outside of Firmware Supervisor on the Nonvolatile Memory tab. Firmware Supervisor adds to the ability to store controller firmware and logic on the removable media. If you disable the Firmware Supervisor, you disable the Firmware Supervisor updates and not the controller firmware updates that still occur when the controller image is reloaded.

Enable or disable the automatic firmware updates by using GSV and SSV instructions.

You can monitor the status of automatic firmware updates.

Monitor the status of automatic firmware updates on the Nonvolatile Memory tab on the controller properties.
To monitor the status of automatic firmware updates for a specific module, use GSV instructions. This example shows that the Firmware Supervisor encountered the wrong hardware revision for 1756-OB16D module.

Access Firmware

The Logix Designer application ships with firmware update kits. Firmware revisions are also available on the Rockwell Automation website.
1. Go to https://www.rockwellautomation.com/global/support/ download-center/overview.page?
2. Under Drivers and Firmware, click Find Drivers and Firmware.

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Index

A
access firmware 132 module object 36
access the module object 36 add-on instruction
guidelines 53 postscan logic 41 prescan 40 addresses serial bit 81 alias tags creating 84 applications HMI 121 array guidelines 77 index
guidelines 78 indirect addresses 77 tag storage 76 atomic data types 75 automatic diagnostics 119
B
base tag guidelines 83
bit tags 80 block-transfer messages
guidelines 113 buffer
message storage 110 routine 39
C
cache messages 110
code reuse guidelines 46
communication Linx-based software data packets 122 module connections 24 MSG instruction 109
comparison import/export, add-on instructions 56 program parameters, add-on instructions 58 programming languages 38 scheduled and unscheduled ControlNet 106 subroutines, add-on instructions 55
compound data types 75 configuration
Logix-based alarms 118 tags 83 connection communication module 24 considerations periodic, event tasks 36 task 34

consumed tag event task 74
continuous task 33 lowest priority 32
controller dual-core 23 Linx-based software software memory 121 resources 23 -scoped tags 122 tag guidelines 125
ControlNet network guidelines 104 scheduled and unscheduled comparison 106 topology 103
creating alias tags 84
D
data scope guidelines 85 type guidelines 75
DeviceNet network guidelines 107 topology 106
diagnostics 119 dual-core
controller 23
E
equipment phases 127 guidelines 127 instructions 128
EtherNet/IP network guidelines 103 topology 102
event task 33 configuration 35 considerations 36 consumed tag 74 guidelines 36
execution project 34 timer 42
F
FactoryTalk software guidelines 122
FactoryTalk Linx software 124 firmware
access 132 management 129 options 130 supervisor guidelines 131

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Index

G
guidelines block-transfer messages 113 controller firmware 129 controller tags 125 ControlNet network 104 DeviceNet network 107 equipment phases 127 EtherNet/IP network 103 FactoryTalk View software 122 firmware supervisor 131 Linx-based software 124 messages 112
H
HMI optimization 121
I
indexed routine 39 inline duplication 38 instructions
equipment phases 128
L
Linx-based software controller memory estimate 121 guidelines 124 network data packet 122
logic routine application code 37
Logix-based alarm configuration 118
M
manage firmware updates 129 system overhead 28
map tags 113 memory
Linx-based software estimation 121 message
block-transfer guidelines 113 cache 110 guidelines 112 storage buffer 110 module object 36 path attribute 37 MSG communication 109

N
network ControlNet guidelines 104 ControlNet topology 103 DeviceNet guidelines 107 DeviceNet topology 106 EtherNet/IP guidelines 103 EtherNet/IP topology 102 guidelines 101 services 101 unscheduled and scheduled ControlNet 106 unscheduled ControlNet guidelines 105
O
online addition of module 99
P
packet Linx-based software data 122
path attribute 37 periodic
task 33 configuration 35 considerations 36
phases equipment 127 PhaseManager option 127
postscan add-on instruction 41 SFC logic 41
pre-defined tasks process controllers 33
prescan add-on instruction 40
priority level task 32
process controllers 33 produced and consumed
RPI 73 tag guidelines 72 tags 71 program considerations 31 languages comparison 38 methods 38 -scoped tags 122 project execution 34
R
routine considerations 31 programming logic 37
RPI produced and consumed tags 73
RSLinx Classic software 124 RSLinx. See also Linx-based Software

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S
serial bit addresses 81 services
network 101 SFC
logic postscan 41 online editing 43 storage message buffer 110 string data types guidelines 82 system overhead manage timeslice 28 timeslice 26
T
table mapping 113
tag configuration 83 controller-scoped 122 descriptions 86 maps 113 name guidelines 85 produced and consumed 71 program-scoped 122
task
considerations 31, 34
continuous, periodic, event 33 priority level 32 types 32 timer execution 42 timeslice manage system overhead 28 system overhead 26 topology ControlNet network 103 DeviceNet network 106 EtherNet/IP network 102
U
UDT guidelines 79
unscheduled ControlNet network guidelines 105
updating firmware 129

Index

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Index
Notes:

136

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Notes:

Logix 5000 Controllers Design Considerations Reference Manual

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