04 - CANopen

Industrial Communication Chapter 4: CANopen

CANopen Features

Industrial Communication Course with Unity Pro - CANopen Schneider Electric Vietnam | Truong Truong Dinh Chau

2

CANopen Features


2

Introduction ●

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

●

CAN in Automation CiA Created in 1991 to promote CAN ● Published standards and Profiles ●

●

CANopen ●

DS-301 profile created in 1995

http://www.can-cia.org Industrial Communication Course with Unity Pro - CANopen Schneider Electric Vietnam | Truong Truong Dinh Chau

3

OSI Layers Used ●

3 Layers Used

APPLICATION

CiA DS-301 = Communication profile CAL = CAN Application Layer

PRESENTATION

Not used

SESSION

Not used

TRANSPORT

Not used

NETWORK

Not used

DATALINK

CAN 2.0 A and B + ISO 11898

PHYSICAL

ISO 11898 + DS-102


4

Physical Layer ●

Error in the doc !

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

●

Characteristic line impedance :120 ohms nominal

●

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)

Industrial Communication Course with Unity Pro - CANopen Schneider Electric Vietnam | Truong Dinh Chau

5

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


250 Kbps

250 m


125 Kbps

500 m


50 Kbps

1000 m


20 Kbps

2500 m (with repeater)


10 Kbps

5000 m (with repeater)



6

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.


7

9-pin SUB D connector ●

DIN 41652

Pin Signal Description: 1: Reserved 2: CAN_L = CAN Low bus line (dominant low) 3: CAN_GND = CAN Ground 4: Reserved 5: (CAN_SHLD) = Optional CAN Shield 6: (GND) = Optional Ground 7: CAN_H = CAN High bus line (dominant high) 8: Reserved 9: (CAN_V+) = Optional CAN external power supply Industrial Communication Course with Unity Pro - CANopen Schneider Electric Vietnam | Truong Dinh Chau

8

RJ 45 Connector ●

Cat 5

1: CAN_H = CAN High bus line (dominant high) 2: CAN_L = CAN Low bus line (dominant low) 3: CAN_GND = Bus ground 4: Reserved 5: Reserved 6: (CAN_SHLD) = Optional CAN Shield 7: CAN_GND = Bus ground 8 (CAN_V+) = Optional CAN external power supply


9

5-pin Mini Style connector ●

ANSI/B93.55M-1981

Male product end Pin Signal Description: 1: (CAN_SHLD) = Optional CAN Shield 2:(CAN_V+) = Optional CAN external power supply 3:CAN_GND = Bus ground 4:CAN_H = CAN High bus line (dominant high) 5:CAN_L = CAN Low bus line (dominant low)


10

Open Style Connector

Male product end

Pin Signal Description: 1:CAN_GND = bus ground 2:CAN_L = CAN Low bus line (dominant low) 3:(CAN_SHLD) = Optional CAN Shield 4:CAN_H = CAN High bus line (dominant high) 5:(CAN_V+) = Optional CAN external power supply


11

Link Layer ●

Industrial Applications: CAN 2.0 A (frame identifier on 11 bits) Arbitration field

1

11

Start of frame (SOF)

Identifier

1

6

RTR Remote Transmission Request bit

Control field compatibility & data length


0 to 64

15

1 1 1

7

CRC ACK delimit. delimit.

Data field useful data (max 8 byte)

CRC field Cyclic redundancy check

ACK slot

End of frame (EOF)

12

4 Types Of Frames ●

Data Frame ●

●

transport data from a producer to consumers without any guarantee that it will be processed.

Remote Frame 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).


13

Protection Mechanisms ●

Very Reliable – Hamming Distance = 6

●

At bit 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 ●

●

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.

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).


14

Robust EMC Behavior ●

Effects of disturbances are minimized Separate GND line ● Differential signal transmission ●

●

Short data frames (8 bytes maximum) Data can still be transmitted in environments that are severely electromagnetically disturbed ● Retransmit only the lost data (not the whole telegram) ●

t


15

Non Destructive Bus Access ●

Prior messages will always be transmitted

●

No telegram loss – no collision (CSMA-CA)

S O F

10

9

8

7

6

5

4

3

2

1

0

R T R

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

Resulting CAN frame

0

0

0

1

1

0

0

0

0

1

0

Identifier

Control Field

Data Field

listing only 0

0

‘0’ is the dominant value


16

Application Layer Producer / Consumer Model ● Flexible Data Transmission ● Data Stored in EDS Files ●

Electronic Data Sheets per device ● CANo en Ob ects reached thanks to Index and SubIndex ●

Index

Objects

0x0000

Reserved

0x0001 – 0x009F

Data Types Area

0x00A0 – 0x0FFF

Reserved

0x1000 – 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


Description

Defines the various types of variables used: bytes, words, signed, unsigned, etc.

17

Functions to Set from DS-301 ●

Network administration ●

●

PDO = Process Data Object (producer-consumer model) ●

●

used for high-speed transmission of process data (<= 8 bytes) – Implicit xc ange

SDO = Service Data Object (client-server model) ●

●

messages are used for starting the bus, assigning identifiers, parameter setting and NMT (Network Management) monitoring (master-slave model)

transmission of parameter setting data (with segmentation can be > 8 bytes) (not time-critical) – Explicit Exchange

SFO = Special Function Object ●

predefined messages for managing synchronization, time references, fatal errors.


18

PDO: 2 parameters

●

PDO Mapping Parameter Which Data to produce / receive ● Object from the EDS file ●

●

PDO Communication Parameters Which target – identifier (COB-ID): Slave to slave synchronization possible ● Transmit / receive modes ● Inhibit time (time between 2 PDO) ●


19

Transmission Modes ●

Synchronous: by receiving a SYNC object Acyclic: ●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: ●transmission is triggered periodically after each 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 ●


20

Transmission Modes (Cont.)

Be careful with analog values ! ● Flexibility & Performance ●

●

Responsiveness

– <1 ms for 256 digital I/Os at 1Mbit/s

Inhibit Time ●

Used to ensure less prioritized PDO to be produced


22

SDO (Service Data Object) Explicit Messaging ● Client / Server Method ●

●

●

Close to Modbus request

Used at Bootup For Configuration


23

SFO ●

SYNC = Synchronization Object

●

EMCY= Emergency Object


24

SFO: Bus Monitoring ●

Node Guarding ●

●

master-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)


25

Configuration with Unity Pro


26

2 Different Tools ●

Premium: TSX SCP 110 Module Sycon Software to configure the bus ● Unity Pro to integrate the configuration ●


27

2 Different Tools (Cont.) ●

M340: CANopen Configuration Tool Embedded inside Unity ● V2 Modules bring more functionalities (BMXP3420x0.2) ●


28

Embedded Devices ●

Included Devices

●

Additionnal Devices ●

Added thanks to the Hardware Catalog tool


29

Device Configuration ●

I/O Objects ●

IODDT generation


30


Channel Function Represent a set of default configuration for a specific device ● Can be added / modify in the Hardware catalogue manager ●


31


PDO Configuration Default PDO activated from the selected device function ● Variables can be added / removed in each PDO ● PDO can be activated / deactivated ● Transmission types can be changed ●


32


Config tab ●

Change the device parameters that will be send to the device during bootup


33

Master Configuration ●

Mapping (Inputs / Outputs Words) ●

●

Needs to be adapted to the correct size!

Bus Parameters ●

Baudrate, inhibit time, SYNC, etc…


34

Exercise ●

Add & Configure a CANopen Device (3-20) – Create a new configuration – Add a new device (Tesys U) and configure it – Configure the master – – Modify PDO parameters and observe the result – Modify the mapping and the configuration send


35

Explicit Exchange ●

SDO Executed Through Function Blocks ADDM: used to define the CANopen address of the targeted slave ● READ_VAR: to send a SDO read object request. ● WRITE_VAR: to send a SDO write object request. ●

●

SDO Online Test


36

ADDM FB ●

IN: ●

●

Out ●

●

String variable: ‘r.m.c.e’ Converted 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


37

READ_VAR FB

●

IN: ADR: to be linked to the output of the ADDM block. ● OBJ: defining object to read (for CANopen: ‘SDO’) ●

●

●

OUT ●

●

NB: number of consecutive objects to read RECP: 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..)


38

WRITE_VAR FB

●

IN: ADR: to be linked to the output of the ADDM block. ● OBJ: defining object to read (for CANopen: ‘SDO’) ●

●

●

EMIS: source table to write from the PLC

IN/OUT ●

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


39

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 –

_ change a configuration parameter (comm loss fallback behaviour)

– Test the application


40

CANopen Application Management ●

Devices Function Blocks Library Tesys ● Motion & Drives ● Etc… ●


41

MFB Library ●

Library to manage Drives


42

MFB Library ●

Commonly Used


43

Compatible with AXIS ●

CANopen AXIS Axis linked to compatible devices only ● Schneider drives and on CANopen only with “MFB” function ●


44

Exercise ●

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


45

04 - CANopen

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