04 - canopen

Industrial CommunicationChapter 4: CANopen

CANopen Features

2Industrial Communication Course with Unity Pro - CANopenSchneider Electric Vietnam | Truong Dinh Chau

Introduction

CAN (Control Area Network)Created by Bosch for automotive industryNew concept of non collision Producer / Consumer model

CAN in Automation (CiA)


CAN in Automation (CiA)Created in 1991 to promote CANPublished standards and Profiles

CANopenDS-301 profile created in 1995

http://www.can-cia.org

OSI Layers Used

3 Layers Used

APPLICATIONCiA DS-301 = Communication profile

CAL = CAN Application Layer


PRESENTATION Not used

SESSION Not used

TRANSPORT Not used

NETWORK Not usedDATALINK CAN 2.0 A and B + ISO 11898PHYSICAL ISO 11898 + DS-102

Physical Layer

Twisted differential pair : 1 pair : CAN_H & CAN_L 2 pairs: CAN_H & CAN_L & Power Supply

Characteristic line impedance :120 ohms nominal

Error in the doc !


Line termination :120 ohms at both ends of the line

Wire resistance : 70 milli-ohms/metre nominal

Topology :Bus type with the shortest possible tap links

Maximum Number of Devices = 127 (1 Master + 126 Slaves)

Bus Length

Depends on the speed

Speed in baud Bus length Length of a junction 1 Mbps 20 m 0,3 m (L. Junction=0,6 m)


800 Kbps 40 m 3 m (L. Junction =6 m) 500 Kbps 100 m 5 m (L. Junction =10 m) 250 Kbps 250 m 5 m (L. Junction =10 m) 125 Kbps 500 m 5 m (L. Junction =10 m) 50 Kbps 1000 m 60 m (L. Junction =120 m) 20 Kbps 2500 m (with repeater) 150 m (L. Junction =300 m) 10 Kbps 5000 m (with repeater) 300 m (L. Junction =600 m)

Physical Connections

3 Categories (DR-303-1)General use

9-pin SUB D connector DIN 41652, multi-pole connector (ribbon cable to 9-pin SUB-D), RJ10 and RJ45


Industrial use 5-pin Mini Style, 5-pin Micro Style, Open Style

Special use 7-pin round connector, 8-pin round connector, 9-pin round

connector, 12-pin round connector, Hand Brid Harting.

9-pin SUB D connector

DIN 41652


Pin Signal Description:1: Reserved2: CAN_L = CAN Low bus line (dominant low)3: CAN_GND = CAN Ground4: Reserved5: (CAN_SHLD) = Optional CAN Shield6: (GND) = Optional Ground7: CAN_H = CAN High bus line (dominant high)8: Reserved9: (CAN_V+) = Optional CAN external power supply

RJ 45 Connector

Cat 5

Pin Signal Description


Pin Signal Description1: CAN_H = CAN High bus line (dominant high)2: CAN_L = CAN Low bus line (dominant low)3: CAN_GND = Bus ground4: Reserved5: Reserved6: (CAN_SHLD) = Optional CAN Shield7: CAN_GND = Bus ground8 (CAN_V+) = Optional CAN external power supply

5-pin Mini Style connector

ANSI/B93.55M-1981


Pin Signal Description:1: (CAN_SHLD) = Optional CAN Shield2:(CAN_V+) = Optional CAN external power supply3:CAN_GND = Bus ground4:CAN_H = CAN High bus line (dominant high)5:CAN_L = CAN Low bus line (dominant low)

Male product end

Open Style Connector

Male product end


Pin Signal Description:1:CAN_GND = bus ground2:CAN_L = CAN Low bus line (dominant low)3:(CAN_SHLD) = Optional CAN Shield4:CAN_H = CAN High bus line (dominant high)5:(CAN_V+) = Optional CAN external power supply

Link Layer Industrial Applications: CAN 2.0 A (frame identifier on 11 bits)

1 11 6 0 to 64 15 71 111

Arbitrationfield


CRC fieldCyclic

redundancy check

Start of frame(SOF)

Identifier

RTRRemote

TransmissionRequest bit

Data fielduseful data

(max 8 byte)

CRC delimit.

ACKslot

ACK delimit.

End of frame(EOF)

Control fieldcompatibility& data length

4 Types Of Frames

Data Frame transport data from a producer to consumers without any guarantee that it

will be processed.

Remote Frame sent by a client to a server to request transmission of a data frame (the


sent by a client to a server to request transmission of a data frame (the identifier will have the same value as that of the request).

Error Frame transmitted when a station detects the presence of errors on the bus.

Overload Frame sent to ask for an additional time lapse between successive frames (data or

request).

Protection Mechanisms

Very Reliable Hamming Distance = 6

At bit level when 5 identical bits are transmitted, an additional "stuffing" bit with the opposite

value is introduced intentionally. This bit is tested and eliminated by the receiver.

At frame structure level


At frame structure level the delimiters CRC Delimiter, ACK Delimiter, End of Frame, Error Delimiter, Overload

Delimiter are integrated to enable the structure to be checked.

At content validity level a Cyclic Redundancy Check (CRC) is used to detect possible transmission errors.

ACK slot this window enables the transmitter to know that his message has been received

correctly by at least one receiver (dominant bit).

Robust EMC Behavior

Effects of disturbances are minimizedSeparate GND lineDifferential signal transmission


Short data frames (8 bytes maximum)Data can still be transmitted in environments that are severely electro-

magnetically disturbed Retransmit only the lost data (not the whole telegram)

t

Non Destructive Bus Access

Prior messages will always be transmitted

No telegram loss no collision (CSMA-CA)

No retransmission necessary


No retransmission necessary

Identifier

10 9 8 7 6 5 4 3 2 1 0 Control Field Data Field

CANopen device 1 0 0 0 1 1 0 0 0 0 0 0 1 0

CANopen device 63 0 0 0 1 1 0 1 listing only

Resulting CAN frame 0 0 0 1 1 0 0 0 0 0 0 1 0

SOF

RTR

0 is the dominant value

Application Layer

Producer / Consumer ModelFlexible Data TransmissionData Stored in EDS Files

Electronic Data Sheets per deviceCANopen Objects reached thanks to Index and SubIndex


CANopen Objects reached thanks to Index and SubIndexIndex Objects Description0x0000 Reserved0x0001 0x009F Data Types Area Defines the various types of variables used: bytes, words, signed,

unsigned, etc.0x00A0 0x0FFF Reserved0x1000 0x1FFF Communication Profile Area Describes the objects associated with communication.0x2000 0x5FFF Manufacturer Specific Profile Area Describes the "application" objects specific to the manufacturer.0x6000 0x9FFF Standardised Device Profile Area Describes the "application" objects standardised by CiA.0xA000 0xFFFF Reserved

Functions to Set from DS-301

Network administrationmessages are used for starting the bus, assigning identifiers, parameter

setting and NMT (Network Management) monitoring (master-slave model) PDO = Process Data Object (producer-consumer model)

used for high-speed transmission of process data ( 8 bytes) (not time-critical) Explicit Exchange

SFO = Special Function Object predefined messages for managing synchronization, time references, fatal

errors.

PDO: 2 parameters


PDO Mapping ParameterWhich Data to produce / receiveObject from the EDS file

PDO Communication ParametersWhich target identifier (COB-ID): Slave to slave synchronization possibleTransmit / receive modes Inhibit time (time between 2 PDO)

Transmission Modes

Synchronous: by receiving a SYNC objectAcyclic:

transmission is pre-triggered by a "Remote Transmission request"transmission is pre-triggered by the occurrence of a "Specific event" object in the device profile (most of the time, change of state)

Cyclic:


Cyclic:transmission is triggered periodically aftereach 1, 2 or up to 240 SYNC objects

Asynchronous: transmission is triggered by a "Remote Transmission request" transmission is pre-triggered by the occurrence of a "Specific event"

object in the device profile

Transmission Modes (Cont.)


Be careful with analog values !Flexibility & Performance

Responsiveness

Inhibit Time

Used to ensure less prioritized PDO to be produced


SDO (Service Data Object)

Explicit MessagingClient / Server Method

Close to Modbus request


Used at Bootup For Configuration

SFO

SYNC = Synchronization Object

Time Stamp Object


Time Stamp Object

EMCY= Emergency Object

SFO: Bus Monitoring

Node Guardingmaster-slave concept (polling), allowing the bus manager to request (remote

request) the status of each station at a configurable time interval.


Heartbeat producer-consumer concept: the status of the station is generated cyclically

at a configurable interval (less bus load & health check between devices possible)

Configuration with Unity Pro


2 Different Tools

Premium: TSX SCP 110 ModuleSycon Software to configure the busUnity Pro to integrate the configuration


2 Different Tools (Cont.)M340: CANopen Configuration Tool

Embedded inside UnityV2 Modules bring more functionalities (BMXP3420x0.2)


Embedded Devices

Included Devices


Additionnal DevicesAdded thanks to the Hardware Catalog tool

Device Configuration

I/O Objects IODDT generation



Channel FunctionRepresent a set of default configuration for a specific deviceCan be added / modify in the Hardware catalogue manager



PDO ConfigurationDefault PDO activated from the selected device functionVariables can be added / removed in each PDOPDO can be activated / deactivatedTransmission types can be changed



Config tabChange the device parameters that will be send to the device during bootup


Master Configuration

Mapping (Inputs / Outputs Words)Needs to be adapted to the correct size!

Bus ParametersBaudrate, inhibit time, SYNC, etc


Exercise

Add & Configure a CANopen Device (3-20) Create a new configuration Add a new device (Tesys U) and configure it Configure the master Test the communication


Test the communication Modify PDO parameters and observe the result Modify the mapping and the configuration send

Explicit Exchange

SDO Executed Through Function BlocksADDM: used to define the CANopen address of the targeted slaveREAD_VAR: to send a SDO read object request.WRITE_VAR: to send a SDO write object request.


SDO Online Test

ADDM FB

IN:String variable: r.m.c.e

OutConverted table of words, to be used in the others FB


r.m.c.e r = the rack number where the CANopen module is located,m = the slot number of the CANopen module, c = the channel used e = the equipment address (slave address) of the target

0.0.2.e

READ_VAR FB

IN:ADR: to be linked to the output of the ADDM block.OBJ: defining object to read (for CANopen: SDO)NUM: subindex and index of the object


NUM: subindex and index of the objectNB: number of consecutive objects to read

OUTRECP: reception zone of the block, delivering the value read (table of

words) IN/OUT

GEST: table of 4 words to manage the communication block (errors, timeout, length, etc..)

WRITE_VAR FB

IN:ADR: to be linked to the output of the ADDM block.OBJ: defining object to read (for CANopen: SDO)NUM: subindex and index of the object


NUM: subindex and index of the objectEMIS: source table to write from the PLC

IN/OUTGEST: table of 4 words to manage the communication block (errors,

timeout, length, etc..)

Exercise

Acyclic Requests SDO (3-27) Monitor the faults of the device Sending SDO using the debug tool to read fault code Sending SDO using the READ_VAR to read fault code Implementing SDO write request with WRITE_VAR to


Implementing SDO write request with WRITE_VAR to change a configuration parameter (comm loss fallback behaviour)

Test the application

CANopen Application Management

Devices Function Blocks LibraryTesysMotion & DrivesEtc


MFB Library

Library to manage Drives


MFB Library

Commonly Used


Compatible with AXIS

CANopen AXISAxis linked to compatible devices onlySchneider drives and on CANopen only with MFB function


Exercise

Manage a Drive with MFB (3-37) Insert the ATV71 inside the configuration Configure the ATV71 using the display Insert MFB functions Test the application


Test the application

CANopen

Main Features Reminder: up to 20m at 1Mbit/s, 1000m w/o repeaters at 50kbit/s high performances < 1ms at 1Mbit/s (1) 5ms polling at 1Mbit/s (2) up to 127 devices (up to 64 per segment)max. 8 byte per telegram, but multiple telegrams per node


very robust EMI behavior: separate ground in the wire + short data frames make it reliable

excellent error detection (HD=6) communication adaptability and flexibility (PDO) non-destructive bus access

04 - canopen

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