EPOS2 Communication Guide En

User Manual:

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Page Count: 54

PLEASE READ THIS FIRST
Table of Contents
1 About this Document
2 Introduction
- 2.1 Documentation Structure
3 EPOS2 Command Reference (USB & RS232)
4 USB Communication
- 4.1 Data Link Layer
- 4.2 Physical Layer
5 RS232 Communication
- 5.1 Data Link Layer
- 5.2 Physical Layer
6 CAN Communication
7 Gateway Communication (USB & RS232 to CAN)
8 Error Code Definition
- 8.1 CANopen-specific Error Codes
- 8.2 maxon-specific Error Codes
List of Figures
List of Tables
Index
- A
- C
- E
- F
- G
- H
- I
- L
- M
- N
- O
- P
- R
- S
- T
- U
- V
- W

maxon motor ag Brünigstrasse 220 P.O.Box 263 CH-6072 Sachseln Phone +41 41 666 15 00 Fax +41 41 666 16 50 www.maxonmotor.com

Edition May 2016

EPOS2 Positioning Controllers

Communication Guide

maxon motor control

Positioning Controllers

Communication Guide

Document ID: rel5984

maxon motor control

A-2 Document ID: rel5984 EPOS2 Positioning Controllers

Edition: May 2016 EPOS2 Communication Guide

PLEASE READ THIS FIRST

These instructions are intended for qualified technical personnel. Prior commencing with any

activities …

• you must carefully read and understand this manual and

• you must follow the instructions given therein.

We have tried to provide you with all information necessary to install and commission the equipment in a

secure, safe and time-saving manner. Our main focus is …

• to familiarize you with all relevant technical aspects,

• to let you know the easiest way of doing,

• to alert you of any possibly dangerous situation you might encounter or that you might cause if

you do not follow the description,

•to write as little and to say as much as possible and

• not to bore you with things you already know.

Likewise, we tried to skip repetitive information! Thus, you will find things mentioned just once. If, for

example, an earlier mentioned action fits other occasions you then will be directed to that text passage

with a respective reference.

Follow any stated reference – observe respective information – then go back and continue with

the task!

PREREQUISITES FOR PERMISSION TO COMMENCE INSTALLATION

The EPOS2 is considered as partly completed machinery according to EU directive 2006/42/EC, Article

2, Clause (g) and therefore is intended to be incorporated into or assembled with other machinery

or other partly completed machinery or equipment.

You must not put the device into service, …

• unless you have made completely sure that the other machinery – the surrounding system the device

is intended to be incorporated to – fully complies with the requirements stated in the EU directive

2006/42/EC!

• unless the surrounding system fulfills all relevant health and safety aspects!

• unless all respective interfaces have been established and fulfill the stated requirements!

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1 About this Document 5

2 Introduction 7

2.1 Documentation Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

3 EPOS2 Command Reference (USB & RS232) 9

3.1 Read Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

3.1.1 Read Object Dictionary Entry (4 Data Bytes and less) . . . . . . . . . . . . . . . . . . . . . . . . . . 9

3.1.2 Read Object Dictionary Entry (5 Data Bytes and more). . . . . . . . . . . . . . . . . . . . . . . . . . 9

3.2 Write Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

3.2.1 Write Object Dictionary Entry (4 Data Bytes and less). . . . . . . . . . . . . . . . . . . . . . . . . . 10

3.2.2 Write Object Dictionary Entry (5 Data Bytes and more). . . . . . . . . . . . . . . . . . . . . . . . . 11

3.2.3 NMT Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

3.3 General CAN Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

4 USB Communication 15

4.1 Data Link Layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

4.1.1 Flow Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

4.1.2 Frame Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

4.1.3 Error Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

4.1.4 Character Stuffing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

4.1.5 Transmission Byte Order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

4.1.6 Timeout Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

4.1.7 Slave State Machine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

4.1.8 Example: Command Instruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

4.2 Physical Layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

5 RS232 Communication 21

5.1 Data Link Layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

5.1.1 Flow Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

5.1.2 Frame Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

5.1.3 Error Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

5.1.4 Transmission Byte Order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

5.1.5 Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

5.1.6 Timeout Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

5.1.7 Slave State Machine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

5.1.8 Example: Command Instruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

5.2 Physical Layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

TABLE OF CONTENTS

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6 CAN Communication 29

6.1 General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

6.1.1 Documentation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

6.1.2 Notations, Abbreviations and Terms used. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

6.2 CANopen Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

6.2.1 Physical Layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

6.2.2 Data Link Layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

6.3 CANopen Application Layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

6.3.1 Object Dictionary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

6.3.2 Communication Objects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

6.3.3 Predefined Communication Objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

6.4 Identifier Allocation Scheme. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

7 Gateway Communication (USB & RS232 to CAN) 45

8 Error Code Definition 47

8.1 CANopen-specific Error Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

8.2 maxon-specific Error Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

About this Document

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1 About this Document

1.1 Intended Purpose

The purpose of the present document is to familiarize you with the described equipment and the tasks

on safe and adequate installation and/or commissioning.

Observing the described instructions in this document will help you …

• to avoid dangerous situations,

• to keep installation and/or commissioning time at a minimum and

• to increase reliability and service life of the described equipment.

Use for other and/or additional purposes is not permitted. maxon motor, the manufacturer of the equip-

ment described, does not assume any liability for loss or damage that may arise from any other and/or

additional use than the intended purpose.

1.2 Target Audience

This document is meant for trained and skilled personnel working with the equipment described. It con-

veys information on how to understand and fulfill the respective work and duties.

This document is a reference book. It does require particular knowledge and expertise specific to the

equipment described.

1.3 How to use

Take note of the following notations and codes which will be used throughout the document.

Table 1-1 Notations used in this Document

For CAN-specific notations, abbreviations and terms page 6-29.

Notation Explanation

«Abcd» indicating a title or a name (such as of document, product, mode, etc.)

(n) referring to an item (such as order number, list item, etc.)

denotes “see”, “see also”, “take note of” or “go to”

About this Document

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1.4 Sources for additional Information

For further details and additional information, please refer to below listed sources:

Table 1-2 Sources for additional Information

1.5 Copyright

The present document – including all parts thereof – is protected by copyright. Any use (including repro-

duction, translation, microfilming and other means of electronic data processing) beyond the narrow

restrictions of the copyright law without the prior approval of maxon motor ag, is not permitted and sub-

ject to persecution under the applicable law.

maxon motor ag

Brünigstrasse 220

P.O.Box 263

CH-6072 Sachseln

Switzerland

Phone +41 41 666 15 00

Fax +41 41 666 16 50

www.maxonmotor.com

#Reference

[ 1 ] CiA 301 Communication Profile for Industrial Systems

www.can-cia.org

[ 2 ] CiA 402 Device Profile for Drives and Motion Control

www.can-cia.org

[ 3 ] CiA 305 Layer Setting Services (LSS) and Protocols

www.can-cia.org

[ 4 ] CiA 306 Electronic Data Sheet Specification

www.can-cia.org

[ 5 ] Bosch’s CAN Specification 2.0

www.can-cia.org

[ 6 ] USB Implementers Forum: Universal Serial Bus Revision 2.0 Specification

www.usb.org/developers/docs

[ 7 ] Konrad Etschberger: Controller Area Network

ISBN 3-446-21776-2

[ 8 ] maxon motor: EPOS2 Communication Guide

EPOS DVD-ROM or www.maxonmotor.com

Introduction

Documentation Structure

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2Introduction

The present document provides you with the communication interfaces details on the EPOS2 Position-

ing Controllers. It contains descriptions of the USB, RS232 and CAN interfaces.

maxon motor control’s EPOS2 is a small-sized, full digital, smart positioning control unit. Due to its flexi-

ble and high efficient power stage, the EPOS2 drives brushed DC motors with digital encoder as well as

brushless EC motors with digital Hall sensors and encoder.

The sinusoidal current commutation by space vector control offers to drive brushless EC motors with

minimal torque ripple and low noise. The integrated position, velocity and current control functionality

allows sophisticated positioning applications. It is specially designed to be commanded and controlled

as a slave node in the CANopen network. In addition, the unit can be operated through any USB or

RS232 communication port.

Find the latest edition of the present document, as well as additional documentation and software to the

EPOS2 Positioning Controllers also on the Internet: www.maxonmotor.com

2.1 Documentation Structure

The present document is part of a documentation set. Please find below an overview on the documenta-

tion hierarchy and the interrelationship of its individual parts:

Figure 2-1 Documentation Structure

Introduction

Documentation Structure

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EPOS2 Command Reference (USB & RS232)

Read Functions

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3 EPOS2 Command Reference (USB & RS232)

3.1 Read Functions

3.1.1 Read Object Dictionary Entry (4 Data Bytes and less)

«ReadObject»

Read an object value from the Object Dictionary at the given Index and SubIndex.

3.1.2 Read Object Dictionary Entry (5 Data Bytes and more)

«InitiateSegmentedRead»

Start reading an object value from the Object Dictionary at the given Index and SubIndex. Use the com-

mand “SegmentRead” to read the data.

Request Frame

OpCode 0x10

Len

Len-1 USB

RS232

WORD Index Index of Object

Parameters (Low) BYTE SubIndex SubIndex of Object

(High) BYTE NodeId Node ID

Response Frame

OpCode 0x00

Len

Len-1 USB

RS232

Parameters DWORD ErrorCode “Error Code Definition” on page 8-47

BYTE Data[4] Data Bytes read

Request Frame

OpCode 0x12

Len

Len-1 USB

RS232

WORD Index Index of Object

Parameters (Low) BYTE SubIndex SubIndex of Object

(High) BYTE NodeId Node ID

Response Frame

OpCode 0x00

Len

Len-1 USB

RS232

Parameters DWORD ErrorCode “Error Code Definition” on page 8-47

EPOS2 Command Reference (USB & RS232)

Write Functions

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«SegmentRead»

Read a data segment of the object initiated with the command “InitiateSegmentedRead”.

3.2 Write Functions

3.2.1 Write Object Dictionary Entry (4 Data Bytes and less)

«WriteObject»

Write an object value to the Object Dictionary at the given Index and SubIndex.

Request Frame

OpCode 0x14

Len

Len-1 USB

RS232

Parameters (Low) BYTE ControlByte

not used

toggle

not used

[Bit 0…5]

[Bit 6]

[Bit 7]

–

Toggle Bit

–

(High) BYTE Dummy Byte without meaning

Response Frame

OpCode 0x00

Len

Len-1 USB

RS232

3…34

2…33

Parameters

DWORD ErrorCode “Error Code Definition” on page 8-47

(Low) BYTE ControlByte

length

toggle

[Bit 0…5]

[Bit 6]

[Bit 7]

Number of data bytes

Toggle Bit

More segments to read

BYTE Data[0…63] Data Bytes read

Request Frame

OpCode 0x11

Len

Len-1 USB

RS232

Parameters

WORD Index Index of Object

(Low) BYTE SubIndex SubIndex of Object

(High) BYTE NodeId Node ID

BYTE Data[4] Data Bytes to write

Response Frame

OpCode 0x00

Len

Len-1 USB

RS232

Data DWORD ErrorCode “Error Code Definition” on page 8-47

EPOS2 Command Reference (USB & RS232)

Write Functions

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3.2.2 Write Object Dictionary Entry (5 Data Bytes and more)

«InitiateSegmentedWrite»

Start writing an object value to the Object Dictionary at the given Index and SubIndex. Use the com-

mand “SegmentWrite” to write the data.

«SegmentWrite»

Write a data segment to the object initiated with the command “InitiateSegmentedWrite”.

Request Frame

OpCode 0x13

Len

Len-1 USB

RS232

Parameters

WORD Index Index of Object

(Low) BYTE SubIndex SubIndex of Object

(High) BYTE NodeId Node ID

DWORD ObjectLength Total number of bytes to write

Response Frame

OpCode 0x00

Len

Len-1 USB

RS232

Data DWORD ErrorCode “Error Code Definition” on page 8-47

Request Frame

OpCode 0x15

Len

Len-1 USB

RS232

1…32

0…31

Parameters (Low) BYTE ControlByte

length

toggle

not used

[Bit 0…5]

[Bit 6]

[Bit 7]

Number of data bytes

Toggle Bit

–

BYTE Data[0…63] Data bytes to write

Response Frame

OpCode 0x00

Len

Len-1 USB

RS232

Data DWORD ErrorCode “Error Code Definition” on page 8-47

(Low) BYTE ControlByte

length

toggle

not used

[Bit 0…5]

[Bit 6]

[Bit 7]

Number of data bytes

Toggle Bit

–

(High) BYTE Dummy Byte without meaning

EPOS2 Command Reference (USB & RS232)

Write Functions

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3.2.3 NMT Service

«SendNMTService»

Send a NMT service to, for example, change NMT state or reset the device.

Remark: *1) no response with RS232

Request Frame

OpCode 0x0E

Len

Len-1 USB

RS232

Parameters

WORD NodeId Node ID

WORD CmdSpecifier

128

129

130

Start Remote Node

Stop Remote Node

Enter Pre-Operational

Reset Node

Reset Communication

Response Frame *1)

OpCode 0x00

Len USB 2

Data DWORD ErrorCode “Error Code Definition” on page 8-47

EPOS2 Command Reference (USB & RS232)

General CAN Commands

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3.3 General CAN Commands

«SendCANFrame»

Send a general CAN Frame to the CAN Bus.

Remark: *1) no response with RS232

«RequestCANFrame»

Request a PDO/Guarding CAN Frame from a CAN Bus using Remote Transmit Request (RTR).

Request Frame

OpCode 0x20

Len

Len-1 USB

RS232

Parameters

WORD Identifier CAN Frame 11-bit Identifier

WORD Length CAN Frame Data Length Code (DLC)

BYTE Data[8] CAN Frame Data

Response Frame *1)

OpCode 0x00

Len USB 2

Data DWORD ErrorCode “Error Code Definition” on page 8-47

Request Frame

OpCode 0x21

Len

Len-1 USB

RS232

Parameters WORD Identifier CAN Frame 11-bit Identifier

WORD Length CAN Frame Data Length Code (DLC)

Response Frame

OpCode 0x00

Len USB

RS232

Data DWORD ErrorCode “Error Code Definition” on page 8-47

BYTE Data[8] CAN Frame Data

EPOS2 Command Reference (USB & RS232)

General CAN Commands

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«SendLSSFrame»

Send a LSS master message to the CAN Bus.

Remark: *1) no response with RS232

«ReadLSSFrame»

Read a LSS slave message from the CAN Bus.

Request Frame

OpCode 0x30

Len

Len-1 USB

RS232

Parameters BYTE Data[8¨] LSS master message

Response Frame *1)

OpCode 0x00

Len USB 2

Data DWORD ErrorCode “Error Code Definition” on page 8-47

Request Frame

OpCode 0x31

Len

Len-1 USB

RS232

Parameters WORD Timeout Communication timeout [ms]

Response Frame

OpCode 0x00

Len USB

RS232

Data DWORD ErrorCode “Error Code Definition” on page 8-47

BYTE Data[8¨] LSS slave message

USB Communication

Data Link Layer

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4 USB Communication

4.1 Data Link Layer

4.1.1 Flow Control

The EPOS2 Positioning Controllers always communicates as a slave. A frame is only sent as an answer

to a request. All EPOS2 commands send an answer. The master always must start the communication

by sending a packet structure.

Below described are the data flow while transmitting and receiving frames.

Figure 4-2 USB Communication – Command Sequence

Figure 4-3 USB Communication – Sending a Data Frame to EPOS2

Figure 4-4 USB Communication – Receiving a Response Data Frame from EPOS2

USB Communication

Data Link Layer

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4.1.2 Frame Structure

The data bytes are sequentially transmitted in frames. A frame composes of…

• a synchronization,

• a header,

• a variably long data field and

• a 16-bit long cyclic redundancy check (CRC) for verification of data integrity.

Figure 4-5 USB Communication – Frame Structure

Note

The CRC is calculated before stuffing the data. The elements “OpCode” to “Data[Len-1]” are included in

CRC calculation. The synchronization elements “DLE” and “STX” are not included.

“DLE”

(8-bit)

“STX”

(8-bit)

OpCode

(8-bit)

Len

(8-bit)

Data[0]

(16-bit) …Data[Len-1]

(16-bit)

CRC

(16-bit)

SYNC HEADER DATA CRC

SYNC The first two bytes are used for frame synchronization.

“DLE” Starting frame character “DLE” (Data Link Escape) = 0x90

“STX” Starting frame character “STX” (Start of Text) = 0x02

HEADER The header consists of 2 bytes. The first field determines the type of data frame to be sent

or received. The next field contains the length of the data fields.

OpCode Operation command to be sent to the slave. For details on the command set

“EPOS2 Command Reference (USB & RS232)” on page 3-9.

Len represents the number of words (16-bit value) in the data fields [0…143].

DATA The data field contains the parameters of the message. The low byte of the word is

transmitted first.

Data[i] The parameter word of the command. The low byte is transmitted first.

CRC The 16-bit CRC checksum using the algorithm CRC-CCITT.

The CRC calculation includes all bytes of the frame except the synchronization bytes, the

data bytes must be calculated as a word.

First, you will need to shift to the data word’s high byte.

This represents the opposite way as you transmit the data word.

For calculation, the 16-bit generator polynomial “x16+x12+x5+1” is used.

CRC Checksum of the frame. The low byte is transmitted first.

USB Communication

Data Link Layer

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4.1.3 Error Control

4.1.3.1 Acknowledge

As a reaction to a bad OpCode or CRC value, the slave sends a frame containing the corresponding

error code.

4.1.3.2 CRC Calculation

Figure 4-6 USB Communication – CRC Calculation

Packet M(x): WORD DataArray[n]

Generator Polynom G(x): 10001000000100001 (= x16+x12+x5+x0)

DataArray[0]:

DataArray[1]:

DataArray[2]:

…

DataArray[n-1]:

HighByte(Len) + LowByte(OpCode)

Data[0]

Data[1]

…

0x0000 (ZeroWord)

WORD CalcFieldCRC(WORD* pDataArray, WORD numberOfWords)

{

WORD shifter, c;

WORD carry;

WORD CRC = 0;

//Calculate pDataArray Word by

Word

while(numberOfWords−−)

{

shifter = 0x8000;

c = *pDataArray++;

{

//Initialize BitX to Bit15

//Copy next DataWord to c

carry = CRC & 0x8000;

CRC <<= 1;

if(c & shifter) CRC++;

if(carry) CRC ^= 0x1021;

shifter >>= 1;

//Check if Bit15 of CRC is set

//CRC = CRC * 2

//CRC = CRC + 1, if BitX is set in c

//CRC = CRC XOR G(x), if carry is true

//Set BitX to next lower Bit, shifter = shifter/2

} while(shifter);

}

return CRC

}

USB Communication

Data Link Layer

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4.1.4 Character Stuffing

The sequence “DLE” and “STX” are reserved for frame start synchronization. If the character “DLE”

appears at a position between “OpCode” and “CRC” and is not a starting character, the character must

be doubled (character stuffing). Otherwise, the protocol begins to synchronize for a new frame. The

character “STX” needs not to be doubled.

Examples:

Important:

Character stuffing is used for all bytes in the frame except the starting characters.

4.1.5 Transmission Byte Order

The unit of data memory in EPOS2 is a word (16-bit value). To send and receive a word (16-bit) via the

serial port, the low byte will be transmitted first.

Multiple byte data (word = 2 bytes, long words = 4 bytes) are transmitted starting with the less significant

byte (LSB) first.

A word will be transmitted in following order: byte0 (LSB), byte1 (MSB).

A long word will be transmitted in following order: byte0 (LSB), byte1, byte2, byte3 (MSB).

4.1.6 Timeout Handling

The timeout is handled over a complete frame. Hence, the timeout is evaluated over the sent data

frame, the command processing procedure and the response data frame. For each frame (frames, data

processing), the timer is reset and timeout handling will recommence.

Table 4-3 USB Communication – Timeout Handling

Note

To cover special requirements, the timeout may be changed by writing to the Object Dictionary!

Sending Data 0x21, 0x90, 0x45

Stuffed Data 0x21, 0x90, 0x90, 0x45

Sending Data 0x21, 0x90, 0x02, 0x45

Stuffed Data 0x21, 0x90, 0x90, 0x02, 0x45

Sending Data 0x21, 0x90, 0x90, 0x45

Stuffed Data 0x21, 0x90, 0x90, 0x90, 0x90, 0x45

Object Index SubIndex Default

USB Frame Timeout 0x2006 0x00 500 [ms]

USB Communication

Data Link Layer

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4.1.7 Slave State Machine

Figure 4-7 USB Communication – Slave State Machine

USB Communication

Physical Layer

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4.1.8 Example: Command Instruction

The following example shows composition and structure of the EPOS2 messages during transmission

and reception via USB. The command sent to the EPOS2 is “ReadObject”, it may be used to read an

object with 4 Bytes and less.

ReadObject “Home Offset” (Index = 0x2081, SubIndex = 0x00)

Table 4-4 ReadObject “Home Offset”

Transmission Order: 0x90,0x02,0x10,0x02,0x81,0x20,0x00,0x01,0x0F,0x87.

The EPOS2 will answer to the command “ReadObject” with an answer frame and the returned parame-

ters in the data block as follows:

Answer to ReadObject “Home Offset” (Index = 0x2081, SubIndex = 0x00)

Table 4-5 Answer to ReadObject “Home Offset”

Reception Order: 0x90,0x02,0x00,0x04,0x00,0x00,0x00,0x00,0x00,0x00,0x90,0x90,0x80,0x14,0x35

Note

Observe character stuffing methodology (



“Character Stuffing” on page 4-18).

4.2 Physical Layer

Electrical Standard

maxon EPOS2 drives’ USB interface follows the «Universal Serial Bus Specification Revision 2.0». You

may wish to download the file from the Internet (for URL “Sources for additional Information” on

page 1-6), full details are described in chapter “7.3 Physical Layer”.

“DLE” “STX” OpCode Len Data[0] Data[1] CRC

0x90 0x02 0x10 0x02 0x2081 0x0100 0x870F

DLE 0x90 = Data Link Escape

STX 0x02 = Start of Text

OpCode 0x10 = ReadObject

Data[0] 0x2081 = 2 Words

LowByte data[1] 0x00 = SubIndex

HighByte data[1] 0x01 = Node ID

“DLE” “STX” OpCode Len-1 Data[0] Data[1] Data[2] Data[3] CRC

0x90 0x02 0x00 0x04 0x0000 0x0000 0x0000 0x8090 0x3514

DLE 0x90 = Data Link Escape

STX 0x02 = Start of Text

OpCode 0x00 = Answer

Len 0x04 = 4 Words

Data[0] 0x0000 = LowWord ErrorCode

Data[1] 0x0000 = HighWord ErrorCode

Data[2] 0x0000 = Value of Object “HomeOffset”

Data[3] 0x8090 = Word without meaning

RS232 Communication

Data Link Layer

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5 RS232 Communication

The serial EIA RS232 communication protocol is used to transmit and receive data over the EPOS2’s

RS232 serial port. Its principal task is to transmit data from a master (PC or any other central processing

unit) to a single slave. The protocol is defined or point-to-point communication based on the EIA-RS232

standard.

The protocol can be used to implement the command set defined for the EPOS2. For a high degree of

reliability in an electrically noisy environment, it features a checksum.

5.1 Data Link Layer

5.1.1 Flow Control

5.1.1.1 Sequence for sending EPOS2 Commands

The EPOS2 Positioning Controllers always communicates as a slave. A frame is only sent as an answer

to a request. Some EPOS2 commands send an answer, other commands do not (observe respective

descriptions to determine command that send an answer packets). The master always must start the

communication by sending a packet structure.

Below described are the data flow while transmitting and receiving frame.

Figure 5-8 RS232 Communication – Command Sequence

5.1.1.2 Sending a Data Frame

When sending a frame, you will need to wait for different acknowledgment.

a) After sending the first frame byte (OpCode), you will need to wait for the EPOS2’s “Ready

Acknowledge”.

b) Once the character “O” (okay) is received, the slave is ready to receive further data.

c) If the character “F” (failed) is received, the slave is not ready to send data and communication

must be stopped.

d) After sending the checksum, you will need to wait for the “End Acknowledge”. The slave

sends either “O” (okay) or “F” (failed).

For the interaction while sending a packet structure Figure 5-9.

RS232 Communication

Data Link Layer

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Figure 5-9 RS232 Communication – Sending a Data Frame to EPOS2

5.1.1.3 Receiving a Data Frame

In response to some of the command frames, the EPOS2 returns a response data frame to the master.

The data flow sequence is identical as for sending a data packet, only in the other direction. The master

must also send the two acknowledges to the slave.

a) The value of the first field must always be 0x00, thus representing the operation code describ-

ing a response frame.

b) After receiving the first byte, the master then must send the “Ready Acknowledge”.

c) Send character “O” (okay) if you are ready to receive the rest of the frame.

d) Send character “F” (failed) if you are not ready to receive the rest of the frame.

e) If the EPOS2 does not get an “O” within the specified timeout, the communication is reset.

Sending “F” does not reset the communication.

f) After sending the “Ready Acknowledge” (“O”), EPOS2 sends the rest of the data frame. Then

the checksum must be calculated and compared with the one received. If the checksum is

correct, send acknowledge “O” to the EPOS2, otherwise send acknowledge “F”.

Figure 5-10 RS232 Communication – Receiving a Response Data Frame from EPOS2

RS232 Communication

Data Link Layer

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5.1.2 Frame Structure

The data bytes are sequentially transmitted in frames. A frame composes of…

• a header,

• a variably long data field and

• a 16-bit long cyclic redundancy check (CRC) for verification of data integrity.

Figure 5-11 RS232 Communication – Frame Structure

OpCode

(8-bit)

Len-1

(8-bit)

Data[0]

(16-bit) …Data[Len-1]

(16-bit)

CRC

16-bit

HEADER DATA CRC

HEADER The header consists of 2 bytes. The first field determines the type of data frame to be sent

or received. The next field contains the length of the data fields.

OpCode Operation command to be sent to the slave. For details on the command set

“EPOS2 Command Reference (USB & RS232)” on page 3-9.

Len-1 represents the number of words (16-bit value) in the data fields.

It contains the number of words minus one. The smallest value in this field is

zero, which represents a data length of one word. The data block must

contain at least 1 word.

Examples:

1 word: Len-1 = 0

2 words: Len-1 = 1

256 words: Len-1 = 255

DATA The data field contains the parameters of the message. This data block must contain at

least one word. The low byte of the word is transmitted first.

Data[i] The parameter word of the command. The low byte is transmitted first.

CRC The 16-bit CRC checksum. The algorithm used is CRC-CCITT. The CRC calculation

includes all bytes of the frame. The data bytes must be calculated as a word.

First you will need to shift in the high byte of the data word.

This is the opposite way you transmit the data word.

The 16-bit generator polynomial “x16+x12+x5+1” is used for the calculation.

Order of CRC calculation:

“OpCode”, “len-1”, “data[0]” high byte, “data[0]” low byte, …, ZeroWord low byte = 0x00,

ZeroWord high byte = 0x00

CRC Checksum of the frame. The low byte is transmitted first.

RS232 Communication

Data Link Layer

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5.1.3 Error Control

5.1.3.1 CRC Calculation

Figure 5-12 RS232 Communication – CRC-CCITT Calculation

5.1.4 Transmission Byte Order

The unit of data memory in EPOS2 is a word (16-bit value). To send and receive a word (16-bit) via the

serial port, the low byte will be transmitted first.

Multiple byte data (word = 2 bytes, long words = 4 bytes) are transmitted starting with the less significant

byte (LSB) first.

A word will be transmitted in following order: byte0 (LSB), byte1 (MSB).

A long word will be transmitted in following order: byte0 (LSB), byte1, byte2, byte3 (MSB).

5.1.5 Data Format

Data is transmitted in an asynchronous way, thus each data byte is transmitted individually with its own

start and stop bit. The format is 1 Start bit, 8 Data bits, No parity, 1 Stop bit. Most serial communication

chips (SCI, UART) can generate such data format.

Packet M(x): WORD DataArray[n]

Generator Polynom G(x): 10001000000100001 (= x16+x12+x5+x0)

DataArray[0]:

DataArray[1]:

DataArray[2]:

…

DataArray[n-1]:

HighByte(OpCode) + LowByte(len-1)

Data[0]

Data[1]

…

0x0000 (ZeroWord)

WORD CalcFieldCRC(WORD* pDataArray, WORD numberOfWords)

{

WORD shifter, c;

WORD carry;

WORD CRC = 0;

//Calculate pDataArray Word by Word

while(numberOfWords−−)

{

shifter = 0x8000;

c = *pDataArray++;

{

//Initialize BitX to Bit15

//Copy next DataWord to c

carry = CRC & 0x8000;

CRC <<= 1;

if(c & shifter) CRC++;

if(carry) CRC ^= 0x1021;

shifter >>= 1;

//Check if Bit15 of CRC is set

//CRC = CRC * 2

//CRC = CRC + 1, if BitX is set in c

//CRC = CRC XOR G(x), if carry is true

//Set BitX to next lower Bit, shifter = shifter/2

} while(shifter);

}

return CRC

}

RS232 Communication

Data Link Layer

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5.1.6 Timeout Handling

The timeout is handled over a complete frame. Hence, the timeout is evaluated over the sent data

frame, the command processing procedure and the response data frame. For each frame (frames, data

processing), the timer is reset and timeout handling will recommence.

Table 5-6 RS232 Communication – Timeout Handling

Note

To cover special requirements, the timeout may be changed by writing to the Object Dictionary!

Object Index SubIndex Default

RS232 Frame Timeout 0x2005 0x00 500 [ms]

RS232 Communication

Data Link Layer

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5.1.7 Slave State Machine

Figure 5-13 RS232 Communication – Slave State Machine

RS232 Communication

Data Link Layer

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5.1.8 Example: Command Instruction

The following example shows composition and structure of the EPOS2 messages during transmission

and reception via serial RS232. The command sent to the EPOS2 is “ReadObject”, it may be used to

read an object with 4 Bytes and less.

ReadObject “Software Version” (Index = 0x2003, SubIndex = 0x01)

Table 5-7 ReadObject “Software Version”

Transmission Order: 0x10,0x01,0x03,0x20,0x01,0x02,0x88,0xA8.

The EPOS2 answers to the command ReadObject with an answer frame and the returned parameters in

the data block as follows:

Answer to ReadObject “Software Version” (Index = 0x2003, SubIndex = 0x01)

Table 5-8 Answer to ReadObject “Software Version”

Reception Order: 0x00,0x03,0x00,0x00,0x00,0x00,0x10,0x20,0x10,0x62,0x10,0x26

OpCode Len-1 Data[0] Data[1] CRC

0x10 0x01 0x2003 0x0201 0xA888

OpCode 0x10 = ReadObject

Len-1 0x01 = 2 Words

Data[0] 0x2003 = Index

LowByte data[1] 0x01 = SubIndex

HighByte data[1] 0x02 = Node ID

OpCode Len-1 Data[0] Data[1] Data[2] Data[3] CRC

0x00 0x03 0x0000 0x0000 0x2010 0x6210 0x2610

OpCode 0x00 = Answer

Len-1 0x03 = 4 Words

Data[0] 0x0000 = LowWord ErrorCode

Data[1] 0x0000 = HighWord ErrorCode

Data[2] 0x2010 = Value of Object “SoftwareVersion”

Data[3] 0x6210 = Word without meaning

RS232 Communication

Physical Layer

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5.2 Physical Layer

Electrical Standard

The EPOS2 communication protocol uses the RS232 standard to transmit data over a 3-wire cable (sig-

nals TxD, RxD and GND).

The RS232 standard can only be used for point-to-point communication between a master and a single

EPOS2 slave. It uses negative, bipolar logic with a negative voltage signal representing a logic “1”, and

positive voltage representing a logic “0”. Voltages of −3…−25 V with respect to signal ground (GND) are

considered logic “1”, whereas voltages of +3…25 V are considered logic “0”.

Medium

For the physical connection, a 3-wire cable will be required. We recommend to install a shielded and

twisted pair cable in order to achieve good performance, even in an electrically noisy environment.

Depending on the bit rate used, the cable length can range from 3…15 meters. However, we do not rec-

ommend to use RS232 cables longer than 5 meters.

CAN Communication

General Information

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6 CAN Communication

6.1 General Information

maxon EPOS2 drives’ CAN interface follows the CiA CANopen specifications…

• CiA 301 V4.2 Communication Profile for Industrial Systems and

• CiA 402 V3.0 Device Profile for Drives and Motion Control.

6.1.1 Documentation

For further information on CAN/CANopen as well as respective specifications listed references in

chapter “1.4 Sources for additional Information” on page 1-6.

6.1.2 Notations, Abbreviations and Terms used

Table 6-9 CAN Communication – Notations

Table 6-10 CAN Communication – Abbreviations

Notation Description Format

nnnnb Numbers followed by “b”. binary

nnnnh Numbers followed by “h”. hexadecimal

nnnn All other numbers. decimal

Abbreviation Description

CAN CAN Application Layer

CMS CAN Message Specification

COB Communication Object (CAN Message) – a unit of transportation in a CAN message

network. Data must be sent across a network inside a COB.

COB-ID COB Identifier – identifies a COB uniquely in a network and determines the priority

of that COB in the MAC sublayer.

EDS Electronic Data Sheet – a standard form of all CAN objects supported by a device.

Used by external CAN configurators.

ID Identifier – the name by which a CAN device is addressed.

MAC Medium Access Control – one of the sublayers of the Data Link Layer in the CAN

Reference Model. Controls the medium permitted to send a message.

OD Object Dictionary – the full set of objects supported by the node. Represents the

interface between application and communication (term “Object” on page 6-30).

PDO Process Data Object – object for data exchange between several devices.

PLC Programmable Controller – can serve as a CAN Master for the EPOS2.

RO Read Only

RW Read Write

SDO Service Data Object – peer-to-peer communication with access to the device’s

Object Directory.

WO Write Only

CAN Communication

General Information

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Table 6-11 CAN Communication – Terms

Term Description

CAN Client

CAN Master

A host (typically a PC or other control equipment) supervising the nodes of a

network.

CAN Server

CAN Slave

A node in the CAN network that can provide service under the CAN Master’s

control.

Object A CAN message with meaningful functionality and/or data. Objects are referenced

according to addresses in the Object Dictionary.

Receive “received” data is being sent from the control equipment to the EPOS2.

Transmit “transmitted” data is being sent from the EPOS2 to the other equipment.

CAN Communication

CANopen Basics

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6.2 CANopen Basics

Subsequently described are the CANopen communication features most relevant to the maxon motor’s

EPOS2 Positioning Controllerss. For more detailed information consult above mentioned CANopen doc-

umentation.

The CANopen communication concept can be described similar to the ISO Open Systems Interconnec-

tion (OSI) Reference Model. CANopen represents a standardized application layer and communication

profile.

Figure 6-14 CAN Communication – Protocol Layer Interactions

6.2.1 Physical Layer

CANopen is a networking system based on the CAN serial bus. It assumes that the device’s hardware

features a CAN transceiver and a CAN controller as specified in ISO 11898. The physical medium is a

differently driven 2-wire bus line with common return.

Figure 6-15 CAN Communication – ISO 11898 Basic Network Setup

CAN Communication

CANopen Basics

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6.2.2 Data Link Layer

The CAN data link layer is also standardized in ISO 11898. Its services are implemented in the Logical

Link Control (LLC) and Medium Access Control (MAC) sublayers of a CAN controller.

• The LLC provides acceptance filtering, overload notification and recovery management.

• The MAC is responsible for data encapsulation (decapsulation), frame coding (stuffing/destuff-

ing), medium access management, error detection, error signaling, acknowledgment, and serial-

ization (deserialization).

A Data Frame is produced by a CAN node when the node intends to transmit data or if this is requested

by another node. Within one frame, up to 8 byte data can be transported.

Figure 6-16 CAN Communication – CAN Data Frame

• The Data Frame begins with a dominant Start of Frame (SOF) bit for hard synchronization of all

nodes.

• The SOF bit is followed by the Arbitration Field reflecting content and priority of the message.

• The next field – the Control Field – specifies mainly the number of bytes of data contained in the

message.

• The Cyclic Redundancy Check (CRC) field is used to detect possible transmission errors. It con-

sists of a 15-bit CRC sequence completed by the recessive CRC delimiter bit.

• During the Acknowledgment (ACK) field, the transmitting node sends out a recessive bit. Any

node that has received an error-free frame acknowledges the correct reception of the frame by

returning a dominant bit.

• The recessive bits of the End of Frame (EOF) terminate the Data Frame. Between two frames, a

recessive 3-bit Intermission field must be present.

With EPOS2, only the Standard Frame Format is supported.

Figure 6-17 CAN Communication – Standard Frame Format

• The Identifier’s (COB-ID) length in the Standard Format is 11 bit.

• The Identifier is followed by the RTR (Remote Transmission Request) bit. In Data Frames, the

RTR bit must be dominant, within a Remote Frame, the RTR bit must be recessive.

• The Base ID is followed by the IDE (Identifier Extension) bit transmitted dominant in the Standard

Format (within the Control Field).

• The Control Field in Standard Format includes the Data Length Code (DLC), the IDE bit, which is

transmitted dominant and the reserved bit r0, also transmitted dominant.

• The reserved bits must be sent dominant, but receivers accept dominant and recessive bits in all

combinations.

CAN Communication

CANopen Application Layer

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6.3 CANopen Application Layer

6.3.1 Object Dictionary

The most significant part of a CANopen device is the Object Dictionary. It is essentially a grouping of

objects accessible via the network in an ordered, predefined fashion. Each object within the dictionary is

addressed using a 16-bit index and a 8-bit subindex. The overall layout of the standard Object Diction-

ary conforms to other industrial field bus concepts.

Table 6-12 CAN Communication – Object Dictionary Layout

A 16-bit index is used to address all entries within the Object Dictionary. In case of a simple variable, it

references the value of this variable directly. In case of records and arrays however, the index

addresses the entire data structure. The subindex permits individual elements of a data structure to be

accessed via the network.

• For single Object Dictionary entries (such as UNSIGNED8, BOOLEAN, INTEGER32, etc.), the

subindex value is always zero.

• For complex Object Dictionary entries (such as arrays or records with multiple data fields), the

subindex references fields within a data structure pointed to by the main index.

An example: A receive PDO, the data structure at index 1400h defines the communication parameters

for that module. This structure contains fields or the COB-ID and the transmission type. The subindex

concept can be used to access these individual fields as shown below.

Table 6-13 CAN Communication – Object Dictionary Entry

Index Variable accessed

0000h Reserved

0001h-009Fh Data types (not supported on EPOS2)

00A0h-0FFFh Reserved

1000h-1FFFh Communication Profile Area (CiA 301)

2000h-5FFFh Manufacturer-specific Profile Area (maxon motor

6000h-9FFFh Standardized Device Area (CiA 402)

A000h-FFFFh Reserved

Index SubIndex Variable accessed Data Type

1400h 0Number of entries UNSIGNED8

1400h 0COB-ID receive PDO1 UNSIGNED32

1400h 2Transmission type receive PDO1 UNSIGNED8

CAN Communication

CANopen Application Layer

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6.3.2 Communication Objects

CANopen communication objects are described by the services and protocols. They are classified as

follows:

• The real-time data transfer is performed by means of Process Data Objects.

• With Service Data Objects, read/write access to entries of a device Object Dictionary is provided.

• Special Function Objects provide application-specific network synchronization and emergency

messages.

• Network Management Objects provide services for network initialization, error control and device

status control.

Table 6-14 CAN Communication – Communication Objects

6.3.3 Predefined Communication Objects

6.3.3.1 PDO Object

PDO communication can be described by the producer/consumer model. Process data can be transmit-

ted from one device (producer) to one another device (consumer) or to numerous other devices (broad-

casting). PDOs are transmitted in a non-confirmed mode. The producer sends a Transmit PDO

(TxPDO) with a specific identifier that corresponds to the identifier of the Receive PDO (RxPDO) of one

or more consumers.

Figure 6-18 CAN Communication – Process Data Object

There are two PDO services:

• The Write PDO is mapped to a single CAN Data frame.

• The Read PDO is mapped to CAN Remote Frame, which will be responded by the corresponding

CAN Data Frame.

Read PDOs are optional and depend on the device capability. The complete data field of up to 8 byte

may contain process data. Number and length of a device’s PDOs are application-specific and must be

specified in the device profile.

Communication Objects

Process Data Objects (PDO)

Service Data Objects (SDO)

Special Function Objects

Synchronization Objects (SYNC)

Time Stamp Objects (not used on EPOS2)

Emergency Objects (EMCY)

Network Management Objects NMT Message

Node Guarding Object

CAN Communication

CANopen Application Layer

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The number of supported PDOs is accessible at the Object Dictionary’s index 1004h. The PDOs corre-

spond to entries in the Object Dictionary and serve as interface to application objects. Application

objects’ data type and mapping into a PDO is determined by a corresponding default PDO mapping

structure within the Object Dictionary. This structure is defined in the entries “1600h” (for the first

R_PDO) and “1A00h” (for the first T_PDO). In a CANopen network, up to 512 T_PDOs and 512

R_PDOs may be used.

Figure 6-19 CAN Communication – PDO Protocol

The CANopen communication profile distinguishes three message triggering modes:

a) Message transmission is triggered by the occurrence of an object-specific event specified in

the device profile.

b) The transmission of asynchronous PDOs may be initiated upon receipt of a remote request

initiated by another device.

c) Synchronous PDOs are triggered by the expiration of a specified transmission period syn-

chronized by the reception of the SYNC object.

Figure 6-20 CAN Communication – PDO Communication Modes

CAN Communication

CANopen Application Layer

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6.3.3.2 SDO Object

With Service Data Objects (SDOs), the access to entries of a device Object Dictionary is provided. A

SDO is mapped to two CAN Data Frames with different identifiers, because communication is con-

firmed. By means of a SDO, a peer-to-peer communication channel between two devices may be estab-

lished. The owner of the accessed Object Dictionary is the server of the SDO. A device may support

more than one SDO, one supported SDO is mandatory and the default case.

Figure 6-21 CAN Communication – Service Data Object

Read and write access to the CANopen Object Dictionary is performed by SDOs. The Client/Server

Command Specifier contains the following information:

• download/upload

• request/response

• segmented/expedited transfer

• number of data bytes

• end indicator

• alternating toggle bit for each subsequent segment

SDOs are described by the communication parameter. The default Server SDO (S_SDO) is defined in

the entry “1200h”. In a CANopen network, up to 256 SDO channels requiring two CAN identifiers each

may be used.

Figure 6-22 CAN Communication – Object Dictionary Access

CAN Communication

CANopen Application Layer

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6.3.3.3 SYNC Object

The SYNC producer provides the synchronization signal for the SYNC consumer.

As the SYNC consumers receive the signal, they will commence carrying out their synchronous tasks. In

general, fixing of the transmission time of synchronous PDO messages coupled with the periodicity of

the SYNC Object’s transmission guarantees that sensors may arrange sampling of process variables

and that actuators may apply their actuation in a coordinated manner. The identifier of the SYNC Object

is available at index “1005h”.

Figure 6-23 CAN Communication – Synchronization Object

Synchronous transmission of a PDO means that the transmission is fixed in time with respect to the

transmission of the SYNC Object. The synchronous PDO is transmitted within a given time window “syn-

chronous window length” with respect to the SYNC transmission and, at the most, once for every period

of the SYNC. The time period between SYNC objects is specified by the parameter “communication

cycle period”.

CANopen distinguishes the following transmission modes:

• synchronous transmission

• asynchronous transmission

Synchronous PDOs are transmitted within the synchronous window after the SYNC object. The priority

of synchronous PDOs is higher than the priority of asynchronous PDOs.

Asynchronous PDOs and SDOs can be transmitted at every time with respect to their priority. Hence,

they may also be transmitted within the synchronous window.

Figure 6-24 CAN Communication – Synchronous PDO

CAN Communication

CANopen Application Layer

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6.3.3.4 EMERGENCY Object

Emergency messages are triggered by the occurrence of a device internal fatal error. They are transmit-

ted by the concerned device to the other devices with high priority, thus making them suitable for inter-

rupt type error alerts.

An Emergency Telegram may be sent only once per “error event”, i.e. the emergency messages must

not be repeated. As long as no new errors occur on a Enter Pre-Operational device, no further emer-

gency message must be sent. The error register as well as additional, device-specific information are

specified in the device profiles by means of emergency error codes defined as to CANopen Communi-

cation Profile.

Figure 6-25 CAN Communication – Emergency Service

6.3.3.5 NMT Services

The CANopen network management is node-oriented and follows a master/slave structure. It requires

one device in the network that fulfils the function of the NMT Master. The other nodes are NMT Slaves.

Network management provides the following functionality groups:

• Module Control Services for initialization of NMT Slaves that want to take part in the distributed

application.

• Error Control Services for supervision of nodes’ and network’s communication status.

• Configuration Control Services for up/downloading of configuration data from/to a network mod-

ule.

A NMT Slave represents that part of a node, which is responsible for the node’s NMT functionality. It is

uniquely identified by its module ID.

Figure 6-26 CAN Communication – Network Management (NMT)

The CANopen NMT Slave devices implement a state machine that automatically brings every device to

“Pre-Operational” state, once powered and initialized.

In “Pre-Operational” state, the node may be configured and parameterized via SDO (e.g. using a config-

uration tool), PDO communication is not permitted. The NMT Master may switch from “Pre-Operational”

to “Operational”, and vice versa.

In “Operational” state, PDO transfer is permitted. By switching a device into “Stopped” state it will be

forced to stop PDO and SDO communication. Furthermore, “Operational” can be used to achieve cer-

tain application behavior. The behavior's definition is part of the device profile’s scope. In “Operational”,

all communication objects are active. Object Dictionary access via SDO is possible. However, imple-

mentation aspects or the application state machine may require to switching off or to read only certain

CAN Communication

CANopen Application Layer

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application objects while being operational (e.g. an object may contain the application program, which

cannot be changed during execution).

Figure 6-27 CAN Communication – NMT Slave State Diagram

CANopen Network Management provides the following five services, which can be distinguished by the

Command Specifier (CS).

Remarks:

*1) Command may be sent with Network Management (NMT) Protocol.

*2) This Transition is generated automatically by the EPOS2 after initialization is completed.

After initialization a Boot-Up message is send.

*3) Remote flag Bit 9 of the Statusword.

Table 6-15 CAN Communication – NMT Slave (Commands, Transitions and States)

Service

Transi-

tion NMT State after

Command Remote

*3 Functionality

–*2 0 Pre-Operational FALSE Communication:

– Service Data Objects (SDO) Protocol

– Emergency Objects

– Network Management (NMT) Protocol

Enter

Pre-Operational 3, 6 Pre-Operational FALSE

Reset

Communication 1, 8, 9 Initialization

(Pre-Operational) FALSE

Calculates SDO COB-IDs.

Setup Dynamic PDO-Mapping and calculates PDO COB-IDs.

Communication:

– While initialization is active, no communication is supported.

– Upon completion, a boot-up message will be sent to the

CAN Bus.

Reset Node 1, 8, 9 Initialization

(Pre-Operational) FALSE

Generates a general reset of EPOS2 software having same

effect as turning off and on the supply voltage. Not saved

parameters will be overwritten with values saved to the

EEPROM using «Save all Parameters».

Start Remote Node 2, 5 Operational TRUE

Communication:

– Service Data Objects (SDO) Protocol

– Process Data Objects (PDO) Protocol

– Emergency Objects

– Network Management (NMT) Protocol

Stop Remote Node 4, 7 Stopped FALSE

Communication:

– Network Management (NMT) Protocol

– Layer setting services (LSS)

– Lifeguarding (Heartbeating)

CAN Communication

CANopen Application Layer

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The communication object possesses the identifier (=0) and consists of two bytes. The Node ID defines

the destination of the message. If zero, the protocol addresses all NMT Slaves.

Figure 6-28 CAN Communication – NMT Object

Table 6-16 CAN Communication – NMT Protocols

Protocol COB-ID CS

(Byte 0) Node ID

(Byte 1) Functionality

Enter

Pre-Operational

00x80 0 (all) All CANopen nodes (EPOS2 devices) will enter NMT State “Pre-

Operational”.

00x80 nThe CANopen node (EPOS2 device) with Node ID “n” will enter

NMT State “Pre-Operational”.

Reset

Communication

00x82 0 (all) All CANopen nodes (EPOS2 devices) will reset the

communication.

00x82 nThe CANopen node (EPOS2 device) with Node ID “n” will reset

the communication.

Reset Node 00x81 0 (all) All CANopen nodes (EPOS2 devices) will reset.

00x81 nThe CANopen node (EPOS2 device) with Node ID “n” will reset.

Start Remote Node

00x01 0 (all) All CANopen nodes (EPOS2 devices) will enter NMT State

“Operational”.

00x01 nThe CANopen node (EPOS2 device) with Node ID “n” will enter

NMT State “Operational”.

Stop Remote Node

00x02 0 (all) All CANopen nodes (EPOS2 devices) will enter NMT State

“Stopped”.

00x02 nThe CANopen node (EPOS2 device) with Node ID “n” will enter

NMT State “Stopped”.

CAN Communication

CANopen Application Layer

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6.3.3.6 Node Guarding Protocol

Used to detect absent devices that do not transmit PDOs regularly (e.g. due of “bus off”). The NMT Mas-

ter can manage “Node Guarding”, a database where, among other information, expected states of all

connected devices are recorded. With cyclic Node Guarding, the NMT Master regularly polls its NMT

Slaves. To detect the absence of the NMT Master, the slaves test internally, whether Node Guarding is

taking place in the defined time interval (Life Guarding).

Node Guarding is initiated by the NMT Master (in “Pre-Operational” state of the slaves) by transmitting a

Remote Frame. Node Guarding is also activated if “Stopped” state is active.

Legend: 1) Data Field / 2) Node Guard Time / 3) Node/Life Guarding Event

Figure 6-29 CAN Communication – Node Guarding Protocol (Timing Diagram)

Data Field

Holds the NMT State. Upon receipt of a node guard answer, bit 8 toggles between 0x00 and 0x80. Thus,

the data field supports the following values:

Table 6-17 CAN Communication – Node Guarding Protocol (Data Field)

Node Guard Time

Is calculated as follows:

Value Toggle EPOS2 NMT State

0x04 not set Stopped

0x84 set Stopped

0x05 not set Operational

0x85 set Operational

0x7F not set Pre-Operational

0xFF set Pre-Operational

NodeGuardTime GuardTime LifeTimeFactor⋅=

CAN Communication

CANopen Application Layer

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Node / Life Guarding Event

In case EPOS2 misses the Remote Transmit Request (RTR), it will change it’s device state to “Error”

(Node Guarding Error).

In case the answer is missed by the Master System, it may react with the Node Guarding Event.

6.3.3.7 Heartbeat Protocol

The Heartbeat Protocol has a higher priority than the Node Guarding Protocol. If both are enabled, only

the Heartbeat Protocol is supported. The EPOS2 transmits a cyclic heartbeat message if the Heartbeat

Protocol is enabled (Heartbeat Producer Time 0 = Disabled / greater than 0 = enabled). The Heartbeat

Consumer guards receipt of the Heartbeat within the Heartbeat Consumer Time. If the Heartbeat Pro-

ducer Time is configured in EPOS2, it will start immediately with the Heartbeat Protocol.

Legend: 1) Data Field / 2) Heartbeat Producer and Heartbeat Consumer Time / 3) Hearbeat Event

Figure 6-30 CAN Communication – Heartbeat Protocol (Timing Diagram)

Data Field

Holds the NMT State. Each time the value of toggle between 0x00 and 0x80. Therefore the following

values for the data field are possible:

Table 6-18 CAN Communication – Heartbeat Protocol (Data Field)

Value EPOS2 NMT State

0x00 Bootup

0x04 Stopped

0x05 Operational

0x7F Pre-Operational

CAN Communication

Identifier Allocation Scheme

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Heartbeat Producer Time and Heartbeat Consumer Time

The Heartbeat Consumer Time must be longer than the Heartbeat Producer Time because of genera-

tion, sending and indication time ( ). Each

indication of the Master resets the Heartbeat Consumer Time.

Heartbeat Event

If EPOS2 is in an unknown state (e.g. supply voltage failure), the Heartbeat Protocol cannot be sent to

the Master. The Master will recognize this event upon elapsed Heartbeat Consumer Time and will gen-

erate a Heartbeat Event.

6.4 Identifier Allocation Scheme

The default ID allocation scheme consists of a functional part (Function Code) and a Module ID, which

allows distinguishing between devices. The Module ID is assigned by DIP switches and a SDO Object.

Figure 6-31 CAN Communication – Default Identifier Allocation Scheme

This ID allocation scheme allows peer-to-peer communication between a single master device and up to

127 slave devices. It also supports broadcasting of non-confirmed NMT Services, SYNC and Node

Guarding.

The predefined master/slave connection set supports…

• one emergency object,

• one SDO,

• four Receive PDOs and three Transmit PDOs and the

• node guarding object.

Table 6-19 CAN Communication – Objects of the Default Connection Set

HeartbeatConsumerTime HeartbeatProducerTime 5ms+≥

Object Function Code

(binary) Resulting COB-ID Communication

Parameter at

Index

NMT 0000 0 –

SYNC 0001 128 (0080h) 1005h

EMERGENCY 129…255 (0081h-00FFh) 1014h

PDO1 (tx) 0011 385…511 (0181h-01FFh) 1800h

PDO1 (rx) 0100 513…639 (0201h-027Fh) 1400h

PDO2 (tx) 0101 641…8767 (0281h-02FFh) 1801h

PDO2 (rx) 0110 769…895 (0301h-037Fh) 1401h

PDO3 (tx) 0111 897…1023 (0381h-03FFh) 1802h

PDO3 (rx) 1000 1025…1151 (0401h-047Fh) 1402h

PDO4 (tx) 1001 1153…1279 (0481h-04FFh) 1803h

PDO4 (rx) 1010 1281…1407 (0501h-057Fh) 1403h

SDO1 (tx) 1011 1409…1535 (0581h-05FFh) 1200h

SDO1 (rx) 1100 1537…1663 (0601h-067Fh) 1200h

CAN Communication

Identifier Allocation Scheme

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Gateway Communication (USB & RS232 to CAN)

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7 Gateway Communication (USB & RS232 to CAN)

Using the gateway functionality, the master can access all other EPOS2 devices connected to the CAN

Bus via the gateway device’s USB port or RS232 interface. Even other CANopen devices (I/O modules)

supporting the CANopen standard CiA 301 may be accessed.

Figure 7-32 Gateway Communication – Structure

Communication data are exchanged between USB/RS232 master and the gateway using a maxon-spe-

cific USB/RS232 protocol.

Data between the gateway and the addressed device are exchanged using the CANopen SDO protocol

according to the CiA 301.

Table 7-20 Gateway Communication – Data Exchange

Step Protocol Sender  Receiver Description

USB

[maxon-specific]

RS232

[maxon-specific]

USB or RS232

Master



EPOS2 ID 1, Gateway

Command including the node ID is sent to the

device working as a gateway. The gateway decides

whether to execute the command or to translate

and forward it to the CAN Bus.

Criteria:

Node ID = 0 (Gateway)

Node ID = DIP switch

else

 Execute

 Forward to CAN

2CANopen [SDO]

EPOS2 ID 1, Gateway



EPOS2 ID 2

The gateway is forwarding the command to the

CAN network. The USB/RS232 command is

translated to a CANopen SDO service.

3CANopen [SDO]

EPOS2 ID 2



EPOS2 ID 1, Gateway

The EPOS2 ID 2 is executing the command and

sending the corresponding CAN frame back to the

gateway.

USB

[maxon-specific]

RS232

[maxon-specific]

EPOS2 ID 1, Gateway



USB or RS232 Master

The gateway is receiving the CAN frame

corresponding to the SDO service. This CAN frame

is translated back to the USB/RS232 frame and

sent back to the USB/RS232 master.

Gateway Communication (USB & RS232 to CAN)

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Error Code Definition

CANopen-specific Error Codes

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8 Error Code Definition

8.1 CANopen-specific Error Codes

Following error codes are defined by CANopen CiA 301 Communication Profile for Industrial Systems:

Error Code Name Cause

0x0000 0000 No Communication Error RS232 communication successful

0x0503 0000 Toggle Error Toggle bit not alternated

0x0504 0000 SDO Time Out SDO protocol timed out

0x0504 0001 Client / Server Specifier Error Client / server command specifier not valid or

unknown

0x0504 0004 CRC Error CRC

0x0504 0005 Out of Memory Error Out of memory

0x0601 0000 Access Error Unsupported access to an object

0x0601 0001 Write Only Error Read command to a write only object

0x0601 0002 Read Only Error Write command to a read only object

0x0602 0000 Object does not exist Error

Object does not exist in Object Directory. Last

read or write command had wrong object

Index or SubIndex

0x0604 0041 PDO mapping Error Object cannot be mapped to the PDO

0x0604 0042 PDO Length Error Number and length of objects to be mapped

would exceed PDO length

0x0604 0043 General Parameter Error General parameter incompatibility

0x0604 0047 General internal Incompatibility Error General internal incompatibility in device

0x0606 0000 Hardware Error Access failed due to hardware error

0x0607 0010 Service Parameter Error Data type does not match, length or service

parameter does not match

0x0607 0012 Service Parameter too long Error Data type does not match, length of service

parameter too high

0x0607 0013 Service Parameter too short Error Data type does not match, length of service

parameter too low

0x0609 0011 Object SubIndex Error Last read or write command had wrong object

SubIndex

0x0609 0030 Value Range Error Value range of parameter exceeded

0x0609 0031 Value too high Error Value of parameter written too high

0x0609 0032 Value too low Error Value of parameter written too low

0x0609 0036 Maximum less Minimum Error Maximum value is less than minimum value

0x0800 0000 General Error General error

0x0800 0020 Transfer or Store Error Data cannot be transferred or stored

Error Code Definition

maxon-specific Error Codes

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Table 8-21 Communication Errors – CANopen-specific Error Codes

8.2 maxon-specific Error Codes

Following error codes are specific to maxon’s EPOS2 devices:

Table 8-22 Communication Errors – maxon-specific Error Codes

0x0800 0021 Local Control Error Data cannot be transferred or stored to

application because of local control

0x0800 0022 Wrong Device State Data cannot be transferred or stored to

application because of present device state

Error Code Name Cause

0x0F00 FFC0 Wrong NMT State Error Device is in wrong NMT state

0x0F00 FFBF Illegal Command Error RS232 command is illegal (does not exist)

0x0F00 FFBE Password Error Password is incorrect

0x0F00 FFBC Service Mode Error Device is not in service mode

0x0F00 FFB9 CAN ID Error Wrong CAN ID

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Figure 2-1 Documentation Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Figure 4-2 USB Communication – Command Sequence. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

Figure 4-3 USB Communication – Sending a Data Frame to EPOS2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

Figure 4-4 USB Communication – Receiving a Response Data Frame from EPOS2 . . . . . . . . . . . . . . . . . . . . . . . . . . .15

Figure 4-5 USB Communication – Frame Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

Figure 4-6 USB Communication – CRC Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

Figure 4-7 USB Communication – Slave State Machine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

Figure 5-8 RS232 Communication – Command Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

Figure 5-9 RS232 Communication – Sending a Data Frame to EPOS2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

Figure 5-10 RS232 Communication – Receiving a Response Data Frame from EPOS2 . . . . . . . . . . . . . . . . . . . . . . . . .22

Figure 5-11 RS232 Communication – Frame Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

Figure 5-12 RS232 Communication – CRC-CCITT Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24

Figure 5-13 RS232 Communication – Slave State Machine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26

Figure 6-14 CAN Communication – Protocol Layer Interactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31

Figure 6-15 CAN Communication – ISO 11898 Basic Network Setup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31

Figure 6-16 CAN Communication – CAN Data Frame. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32

Figure 6-17 CAN Communication – Standard Frame Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32

Figure 6-18 CAN Communication – Process Data Object . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34

Figure 6-19 CAN Communication – PDO Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35

Figure 6-20 CAN Communication – PDO Communication Modes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35

Figure 6-21 CAN Communication – Service Data Object . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36

Figure 6-22 CAN Communication – Object Dictionary Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36

Figure 6-23 CAN Communication – Synchronization Object . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37

Figure 6-24 CAN Communication – Synchronous PDO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37

Figure 6-25 CAN Communication – Emergency Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38

Figure 6-26 CAN Communication – Network Management (NMT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38

Figure 6-27 CAN Communication – NMT Slave State Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39

Figure 6-28 CAN Communication – NMT Object . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40

Figure 6-29 CAN Communication – Node Guarding Protocol (Timing Diagram). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41

Figure 6-30 CAN Communication – Heartbeat Protocol (Timing Diagram) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42

Figure 6-31 CAN Communication – Default Identifier Allocation Scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43

Figure 7-32 Gateway Communication – Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45

LIST OF FIGURES

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Table 1-1 Notations used in this Document . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Table 1-2 Sources for additional Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Table 4-3 USB Communication – Timeout Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Table 4-4 ReadObject “Home Offset”. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Table 4-5 Answer to ReadObject “Home Offset” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Table 5-6 RS232 Communication – Timeout Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Table 5-7 ReadObject “Software Version” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Table 5-8 Answer to ReadObject “Software Version”. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Table 6-9 CAN Communication – Notations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Table 6-10 CAN Communication – Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Table 6-11 CAN Communication – Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Table 6-12 CAN Communication – Object Dictionary Layout. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Table 6-13 CAN Communication – Object Dictionary Entry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Table 6-14 CAN Communication – Communication Objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Table 6-15 CAN Communication – NMT Slave (Commands, Transitions and States) . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Table 6-16 CAN Communication – NMT Protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Table 6-17 CAN Communication – Node Guarding Protocol (Data Field) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Table 6-18 CAN Communication – Heartbeat Protocol (Data Field) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Table 6-19 CAN Communication – Objects of the Default Connection Set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Table 7-20 Gateway Communication – Data Exchange. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Table 8-21 Communication Errors – CANopen-specific Error Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Table 8-22 Communication Errors – maxon-specific Error Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

LIST OF TABLES

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Access Error 47

access to CAN bus via USB or RS232 45

applicable EU directive 2

CAN

commands 13

communication 29

error codes 47

CAN (definition) 29

CAN Client (definition) 30

CAN Master (definition) 30

CAN Server (definition) 30

CAN Slave (definition) 30

Client / Server Specifier Error 47

CMS (definition) 29

COB (definition) 29

COB-ID (definition) 29

codes (used in this document) 5

communication via gateway 45

EDS (definition) 29

Error CAN ID 48

error codes 47

Error Service Mode 48

EU directive, applicable 2

functions

write 10

General Error 47

General internal Incompatibility Error 47

General Parameter Error 47

Hardware Error 47

Heartbeat Consumer Time, calculation of 43

how to

read this document 2

ID (definition) 29

Illegal Command Error 48

incorporation into surrounding system 2

InitiateSegmentedRead (function) 9

InitiateSegmentedWrite (function) 11

intended purpose 7

Life Guarding 41

Local Control Error 48

MAC (definition) 29

Maximum less Minimum Error 47

NMT State

Heartbeat 42

Node Guarding 41

No Communication Error 47

Node Guard Time, calculation of 41

Node Guarding 41

non-compliance of surrounding system 2

notations (used in this document) 5

Object (definition) 30

Object does not exist Error 47

Object SubIndex Error 47

OD (definition) 29

operating license 2

OSI Reference Model 31

other machinery (incorporation into) 2

Out of Memory Error 47

Password Error 48

PDO (definition) 29

PDO Length Error 47

PDO mapping Error 47

PLC (definition) 29

prerequisites prior installation 2

purpose

of the device 7

of this document 5

INDEX

maxon motor control

Z-52 Document ID: rel5984 EPOS2 Positioning Controllers

Edition: May 2016 EPOS2 Communication Guide

ReadLSSFrame (function) 14

ReadObject (function) 9

Receive (definition) 30

RequestCANFrame (function) 13

RO (definition) 29

RS232

command reference 9

communication 21

to CAN Gateway 45

RW (definition) 29

SDO (definition) 29

SDO Time Out 47

SegmentedWrite (function) 11

SegmentRead (function) 10

SendCANFrame (function) 13

SendLSSFrame (function) 14

SendNMTService (function) 12

Service Parameter Error 47

Service Parameter too long Error 47

Service Parameter too short Error 47

surrounding system (incorporation into) 2

Toggle Error 47

Transfer or store Error 47

Transmit (definition) 30

USB

command reference 9

communication 15

to CAN Gateway 45

Value Range Error 47

Value too high Error 47

Value too low Error 47

WO (definition) 29

Write Only 47

WriteObject (function) 10

Wrong Device State 48

Wrong NMT State Error 48

maxon motor control

EPOS2 Positioning Controllers Document ID: rel5984 Z-53

EPOS2 Communication Guide Edition: May 2016

••page intentionally left blank••

maxon motor control

Z-54 Document ID: rel5984 EPOS2 Positioning Controllers

Edition: May 2016 EPOS2 Communication Guide

The present document – including all parts thereof – is protected by copyright. Any use (including reproduction, translation,

microfilming and other means of electronic data processing) beyond the narrow restrictions of the copyright law without the

prior approval of maxon motor ag, is not permitted and subject to persecution under the applicable law.

maxon motor ag

Brünigstrasse 220

P.O.Box 263

CH-6072 Sachseln

Switzerland

Phone +41 41 666 15 00

Fax +41 41 666 16 50

www.maxonmotor.com

EPOS2 Communication Guide En

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