Section 2 - Slide 1/61 P&T - GPS - Training PhW - CANopen_lev2_en 10/2004 CANopen CANopen Section 1: History Section 2: Physical layer Section 3: Link

P&T - GPS - TrainingPhW - CANopen_lev2_en 10/2004

Section 2 - Slide 1/61

CANopenCANopen Section 1: History

Section 2: Physical layer

Section 3: Link layer

Section 4: Application layer

Section 4: Main characteristics resume



CANopenCANopen

Section 1: History



Section 1 : HistorySection 1 : History

HistoryHistory

1980-1983: CAN developed on the initiative of the German equipment manufacturer BOSCH in response to a need in the automotive industry.

CAN defines only part of layers 1 and 2 of the ISO model.

1983-1987:

Price of drivers and micro-controllers with integral CAN very attractive because of the high volume used by the automotive industry

1991:

Launch of CiA = CAN in Automation: http://www.can-cia.de/ to promote industrial applications



Section 1 : HistorySection 1 : History

HistoryHistory

1995:

Publication by CiA of the DS-301 communication profile: CANopen

2001:

Publication by CiA of DS-304, enabling level 4 safety components to be integrated onto a standard CANopen bus (CANsafe).

1993:

Publication by CiA of CAL = CAN Application Layer specifications describing transmission mechanisms without defining when and how to use them.



CANopen was built chronologically on the basis of several specifications:

• CAN 2.0 A and B (originating from Robert BOSCH)

Defines precisely the link layer and part of the physical layer

• CAL = CAN Application Layer (CiA):

Provides tools for developing an application using CAN without instructions for use + further details on the physical layer

• CANopen (CiA):

Defines which CAL tools to use and how.

Ensures interoperability of products by profile descriptions.

Reference specificationsReference specifications

Section 1 : History



Section 1 : History

CiA DS-301 = Communication profile

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CAN 2.0 A and B + ISO 11898

CAN 2.0 A and B = ISO 11898

ISO 11898 + DS-102

Device ProfileCiA DSP-401I/O modules

Device ProfileCiA DSP-402

Drives


Measuring devices

Device ProfileCiA DSP-4xx

CAL= CAN Application Layer APPLICATION

PRESENTATION

SESSION

TRANSPORT

NETWORK

LINK = LLC + MAC

PHYSICAL

7

6

5

4

3

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CANopen and the ISO model

CANopen and the ISO model

CA

N

sp

ec

ific

ati

on

s



CANopenCANopen

Part 1: Network characteristics

Part 2: Recommended connections

Section 2: Physical layer




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ISO 11898 + DS-102 + DRP-301-1



Drives


Measuring devices



PRESENTATION

SESSION

TRANSPORT

NETWORK

LINK = LLC + MAC

PHYSICAL

7

6

5

4

3

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1

Section 2: Physical layer - Part 1: Network characteristics

CANopenphysical layer

CANopenphysical layer



Twisted differential pair: 1 pair if CAN-H/CAN-L

2 pairs if CAN-H/CAN-L + p. supply

Characteristic line impedance: 120 ohms nominal

Line terminators: 120 ohms at each end

Wire resistance: 70 milli-ohms/metre nominal

Propogation time: 5 ns/metre nominal

Topology: Bus type with the shortest possible tap links

Description of the networkDescription of the network




Data rate - bus length - cable cross-section for 32 slaves maximumData rate - bus length - cable cross-section for 32 slaves maximum


Data rate Bus length Cable x-section

1 Mbps 25 m 0.25 mm2 AWG 23

800 Kbps 50 m 0.34 mm2 AWG 22

500 Kbps 100 m 0.34 mm2 AWG 22

250 Kbps 250 m 0.34 mm2 AWG 22

125 Kbps 500 m 0.5 mm2 AWG 20

50 Kbps 1000 m 0.75 mm2 AWG 18

20 Kbps 1000 m 0.75 mm2 AWG 18

10 Kbps 1000 m 0.75 mm2 AWG 18



Data rate - bus length - cable cross-section for 100 slaves maximum

Data rate - bus length - cable cross-section for 100 slaves maximum


Data rate Bus length Cable x-section

1 Mbps 25 m 0.34 mm2 AWG 22

800 Kbps 50 m 0.6 mm2 AWG 20

500 Kbps 100 m 0.6 mm2 AWG 20

250 Kbps 250 m 0.6 mm2 AWG 20

125 Kbps 500 m 0.75 mm2 AWG 18

50 Kbps 1000 m 1 mm2 AWG 17

20 Kbps 1000 m 1 mm2 AWG 17

10 Kbps 1000 m 1 mm2 AWG 17



In its recommendation DR-303-1, the CiA provides a list of suitable connectors classified into 3 categories.

General use9-pin SUB D connector DIN 41652, multi-pole connector (ribbon cable to 9-pin SUB-D), RJ10 and RJ45

Industrial use5-pin Mini Style, 5-pin Micro Style, Open Style

Special use7-pin round connector, 8-pin round connector, 9-pin round connector, 12-pin round connector, Hand Brid Harting.

Recommended connections Recommended connections

Section 2: Physical layer - Part 2: Recommended connections



Pin Signal Description:1: Reserved

2: CAN_L = CAN_L 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_H bus line dominant high

8: Reserved

9: (CAN_V+) Optional CAN external positive supply

9-pin SUB D connector DIN 416529-pin SUB D connector DIN 41652


Male product end



RJ45 connectorRJ45 connector


Pin Signal Description

1: CAN_H = CAN_H bus line (dominant high)

2: CAN_L = CAN_L bus line (dominant low)

3: CAN_GND = Ground/0 V/V-

4: Reserved

5: Reserved

6: (CAN_SHLD) = Optional CAN Shield


8 (CAN_V+) = Optional CAN external positive supply



Pin Signal Description:


2: (CAN_V+) = Optional CAN external positive supply

3: CAN_GND = Ground/0V/V-



5-pin Mini Style connector: ANSI/B93.55M-19815-pin Mini Style connector: ANSI/B93.55M-1981


Male product end



Pin Signal Description:





5: (CAN_V+) = Optional CAN external positive supply

Open Style connectorOpen Style connector


Male product end



Recommended suppliersRecommended suppliers


Cables

- U.I.LAPP GmbHSchultze-Delitsch-Str. 25D-70565 Stuttgart Germany

http://www.lappcable.com

Connectors- ERNI Elektroapparate GmbH

Seestrasse 9 D-73099 Adelberg Germany

- ERNI Connectique S.a.r.l, France27 bis, avenue des Sources/CP 638 F-69258 LYON Cedex 09,

http://connect.erni.com/



CANopenCANopen




The CAN V2.0 specification consists of 2 parts: CAN 2.0.A and CAN 2.0.B.

CAN 2.0.A corresponds to the standard frame format with an identifier coded on 11 bits. It is used by CANopen and most of the application layers.

CAN 2.0.B corresponds to the extended frame format with an identifier coded on 29 bits. It is very rarely used.

CAN 2.0.A and CAN 2.0.BCAN 2.0.A and CAN 2.0.B





CRC sequence

Start of frame (SOF)

Identifier

RTR RemoteTransmissionRequest bit

Data field CRC delimit.

Structure of the CAN 2.0.A frameStructure of the CAN 2.0.A frameStructure of the CAN 2.0.A frameStructure of the CAN 2.0.A frame

ACKslot

1 11 6 0 to 64 15 71 111

ACK delimit.

End offrame(EOF)

Arbitrationfield

Control field:compatibilityand length

Frame size without bit stuffing: 47 to 111 bits




Dominant and recessive bitsDominant and recessive bits

10 9 8 7 6 5 4 3 2 1 0SO

FS

OF

RT

RR

TR ControlControl

fieldfield

IdentifierIdentifier

Station 1Station 1

Station 2Station 2

Station 3Station 3

DD

RR

S1S1 S2S2 S3S3

Station 2loses arbitration

Station 1loses arbitration

BusBus



Each node must always contain two counters:

TEC Transmit Error Counter and REC Receive Error Counter.

These counters are incremented and decremented using a sophisticated weighting mechanism etched in the silicon.

Depending on the value of these counters, the node will be in one of the following 3 states:

Active errors

Passive errors

Bus OFF (sending driver disconnected from the bus).

Error countersError counters




Counter value/node statusCounter value/node status


Active errors

Passiveerrors

Bus OFF

Reset and configuration

REC > 127or TEC > 127

REC < 128and TEC < 128

TEC > 255

128 occurrences of 11 consecutive

recessive bits (end of frames without

errors)



Data Frame: these frames transport data from a producer to consumers without any guarantee that it will be processed.

Remote Frame: these request frames are 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: these frames are transmitted when a station detects the presence of errors on the bus.

Overload Frame: these frames are sent to ask for an additional time lapse between successive frames (data or request).

The 4 types of CAN frameThe 4 types of CAN frame





SOF IDENT RTR CTR DATA CRC ACK EOF

1D

CAN V2.0 A Data FrameCAN V2.0 A Data FrameCAN V2.0 A Data FrameCAN V2.0 A Data Frame

0 to 64X 1X+1R5X+1R6X11X 1D 7R

SOF IDENT RTR CTR DATA CRC ACK EOF

1D

CAN V2.0 A Remote FrameCAN V2.0 A Remote FrameCAN V2.0 A Remote FrameCAN V2.0 A Remote Frame

0 to 64X 1X+1R5X+1R6X11X 7R1R

Data frame

Request frame

Interframe

3R

Interframe

3R

If a request frame is repeated, the response to this request takes priority.




ERROR FLAG ERROR DELIMITER

Error FrameError FrameError FrameError Frame

ACTIVE ERROR FLAG: 6D 8R

Frame being broadcast

Error detected

PASSIVE ERROR FLAG: 6R

OVERLOAD FLAG OVERLOAD DELIMITER

Overload FrameOverload FrameOverload FrameOverload Frame

6D 8R

Previous frame

EOF or ERROR DELIMITER



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, 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 CRC sequence enables receivers to check the consistency of the data received.

ACK slot: this window enables the sender to know that his message has been received correctly by at least one station (dominant bit).

Protection mechanismsProtection mechanisms




CANopenCANopen

Part 1: CANopen basic concepts

Part 2: CANopen objects and services

Section 4: Application layer




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CAN 2.0 A and B = ISO 11898-1 and 2

ISO 11898 + DS-102



Drives


Measuring devices



PRESENTATION

SESSION

TRANSPORT

NETWORK

LINK = LLC + MAC

PHYSICAL

7

6

5

4

3

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Section 4: Application layer - Part 1: CANopen basic concepts

CANopen is based on CAL

CANopen is based on CAL




CANopen defines:

how data is transmitted:

DS-301 communication profile common to all products

Amongst other things this defines the allocation of COB-ID identifiers for each type

of message.

what data is transmitted:

DS-4xx product profiles specific to each product family

(discrete I/O, analogue I/O, variable speed drives, encoders, etc.)

These functions are described by means of a Device Object Dictionary (OD).

Application layerApplication layer




The object dictionary OD is a sequenced group of objects that can be accessed by means of:

a 16-bit index and in some cases an 8-bit sub-index

It describes all the functions of the product.

This description takes the form of an EDS file (Electronic Data Sheet)

in ASCII format. This has a strict syntax and can be used by the bus configurators (Sycon etc.)

Object Dictionary = ODObject Dictionary = OD




Structure of the “Object Dictionary”Structure of the “Object Dictionary”

Index Objects Description

0x0000 Reserved

0x0001 – 0x009F Data Types Area Defines the various types of variables used: bytes, words, double words, signed, unsigned, etc.

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




The DS-301 communication profile:

Describes the general structure of the OD and the objects located in the communication profile area: index 1000 to 1FFF.

It applies to all CANopen products.

DS-4xx equipment profiles:

Describe associated objects for the various types of product (discrete I/O modules, analogue I/O, variable speed drives, measuring instruments).

Standardised objects: index 6000 to 9FFF

Specific objects: index 2000 to 5FFF

Some objects are mandatory, others are optional. They can be accessed in read-only mode or in read/write mode.

CANopen profilesCANopen profiles




CANopen ATV58 EDS file extractCANopen ATV58 EDS file extractCANopen ATV58 EDS file extractCANopen ATV58 EDS file extract

[FileInfo]

FileName=A58_F.eds

FileVersion=1

FileRevision=2

Description=Carte Option ATV58

CreationTime=00:00AM

CreationDate=12-05-2000

CreatedBy=Marie-Annick Menanteau, Schneider Electric

[DeviceInfo]

VendorName=Schneider Electric

ProductName=ATV58_F

ProductVersion=1

ProductRevision=1

BaudRate_10=0

BaudRate_20=0

BaudRate_50=0

BaudRate_100=0

BaudRate_125=1

BaudRate_250=1

BaudRate_500=1

BaudRate_800=0

BaudRate_1000=1

Granularity=0x8

VendorNumber=0x0200005a

ProductNumber=0

SimpleBootUpMaster=0

ExtendedBootUpMaster=0

SimpleBootUpSlave=1

ExtendedBootupSlave=0….

[Comments]

Lines=6

Line1=Used profile: 402

Line2=Manufacturer device name: VW3A58306

Line3=Hardware version: 1.0

Line4=Software version: 1.0

Line6= This is the EDS file for the CANopen Schneider Electric ATV58 drive module CAN Communication Adapter

[MandatoryObjects]

SupportedObjects=12

1=0x1000

2=0x1001

3=0x6040

4=0x6041

5=0x6042

6=0x6043

7=0x6044

8=0x6046

9=0x6048

10=0x6049

11=0x6060

12=0x6061

[1000]

ParameterName=Device Type

ObjectType=7

DataType=0x0007

AccessType=RO

DefaultValue=0x10192

PDOMapping=0




CANopen communication profile DS-301CANopen communication profile DS-301

The CANopen communication profile defines 4 standardised functions:

1 . Network administration: starting the bus, assigning identifiers, parameter setting and NMT (Network ManagemenT) monitoring (master-slave model)

2 . High-speed transmission of process data (<= 8 bytes):

PDO = Process Data Object (producer-consumer model)

3 . - Transmission of parameter setting data (with segmentation can be > 8 bytes) (not time-critical):

SDO = Service Data Object (client-server model)

4 . Predefined messages for managing synchronisation, time references, fatal errors: SFO = Special Function Object



Section 4: Application layer - Part 2: CANopen objects and services

Transitions performed by the NMT master: Types of communication objects authorised:

1: Start_Remote_Node a. NMT

2: Stop_Remote_Node b. Node Guard

3: Enter_Pre-Operational_State c. SDO

4: Reset_Node d. EMCY

5: Reset_Communication e. PDO.

6: Node initialisation stopped

Network management: NMTNetwork management: NMT

Status chart corresponding to “CANopen minimum boot-up”*

(mandatory service)

Starting the busStarting the bus




Allocation of identifiersAllocation of identifiers

Identifiers can be allocated in 3 different ways:

Using the default allocation: CANopen Predefined Set

This default allocation is compulsory and is available in the Pre-Operational state.

It reduces the network configuration phase

Process data is exchanged between the bus manager and the slaves

Defined only for the first 4 PDOs : PDO1 to PDO4

By the user in the configuration tool :

Mandatory for PDOs superior to PDO4, or PDO linking (direct exchanges between

slaves)

By application Pre-Operational state:

Written into the objects in accordance with the dictionary by the SDO service



With the aim of reducing the network configuration phase a compulsory system for allocating default identifiers has been defined.

This allocation occurs in the "Pre operational" state just after the initialization phase.

It is based on dividing the COB-ID identifier into 2 parts:

Function code is used to code 2 PDOs in receive mode, 2 PDOs in transmit mode, 1 SDO, 1 EMCY object, 1 Node Guarding Identifier, 1 SYNC object, 1 Time Stamp object and 1 node guarding.

Node ID corresponds to the product address coded by DIP switches, for example.

Allocation of default identifiersAllocation of default identifiers


10 9 8 7 6 5 4 3 2 1 0

Function Code Node ID





Allocation of default identifiers can be used on products

which support the first 4 PDOs.

(The fifth PDO overlaps the area reserved for SDO)

10

24

id

en

tifi

ers

ma

xim

um

re

se

rve

dfo

r P

DO

s.

General broadcast objects

Object Function Code Bin COB-ID Hex COB-ID Dec NMT 0000 0x000 0

SYNC 0001 0x080 128

TIME STAMP 0010 0x100 256

Point to point broadcast objects

Object Function Code Bin COB-ID Hex COB-ID Dec Emergency 0001 0x081to 0x0FF 129 to 255

Transmit PDO 1 0011 0x181 to 0x1FF 385 to 511

Receive PDO 1 0100 0x201 to 0x27F 513 to 639







SDO server 1011 0x581 to 0x5FF 1409 to 1535

SDO client 1100 0x601 to 0x67F 1537 to 1663

NODE GUARD 1110 0x701 to 0x77F 1793 to 1919




RxPDO_1_SL1RxPDO_2_SL1RxPDO_1_SL2RxPDO_2_SL2RxPDO_1_SL3RxPDO_2_SL3

TxPDO_1_SL1TxPDO_2_SL1TxPDO_1_SL2TxPDO_2_SL2TxPDO_1_SL3TxPDO_2_SL3

TxPDO_1_SL1TxPDO_2_SL1

RxPDO_1_SL1RxPDO_2_SL1





MasterMaster

Slave 1Slave 1

Slave 2Slave 2

Slave 3Slave 3

All the nodes (slaves)

communicate witha central station

(master)

Inp

uts

Inp

uts

Ou

tpu

ts

Ou

tpu

ts





Modification of the default identifier allocationModification of the default identifier allocation

TxPDO_1_PXTxPDO_2_PX

RxPDO_1_PXRxPDO_2_PX

TxPDO_1_PYTxPDO_2_PY

RxPDO_1_PYRxPDO_2_PYRxPDO_3_PY

TxPDO_1_PZTxPDO_2_PZ

RxPDO_1_PZRxPDO_2_PZRxPDO_3_PZ

Product XProduct X

Product YProduct Y Product ZProduct Z

Allows data to be exchangeddirectly without passing

through the master(PDO linking).

The producer-consumerconcept is used.

Example: Axis control



These services are used to transmit small amounts of process data (<= 8 bytes) in real time.

They enable a producer device to make a variable with a maximum size of 64 bits without overhead available to one or more consumers.

This service is not confirmed

PDO configuration is managed at the level of each slave

There are 2 types of PDOs :Receive PDO : PDO received on slave side, output data for the masterTransmit PDO : PDO sent by the slave, input data for the master

Process Data Objects = PDOProcess Data Objects = PDOProcess Data Objects = PDOProcess Data Objects = PDO





Each transmit or receive PDO is described by 2 objects in the object dictionary:

The PDO Communication Parameter indicates how the PDO is transmitted or received:

The COB-ID used The transmit/receive mode used For transmit PDOs, the minimum time between 2 messages

(inhibit time)Receive PDO : Index 1400 to 15FF - Transmit PDO : Index 1800 to 19FF

The PDO Mapping Parameter indicates what data is transmitted: The list of objects in the object dictionary OD The size of each object

Receive PDO : Index 1600 to 17FF - Transmit PDO : Index 1A00 to 1BFF

Description of PDOsPDOsDescription of PDOsPDOs



TxPDO communication parameter objectsTxPDO communication parameter objects


Transmit PDO: Index 0x1800 to 0x19FFTransmit PDO: Index 0x1800 to 0x19FF

Index Sub-Index

Name Format Default value

Description

0 Number of elements Byte 3 Number of elements following

1 COB-ID Double word

Depends on the PDO

number and the node ID

11 least significant bits = COB-ID Bit 31 = indicates whether the PDO is active or not Bit 30 = indicates whether remote frame access is supported or not.

2 Transmission

type Byte Depends

on the product

Describes how the PDO is transmitted: synchronously or asynchronously, on change of state, cyclically, on polling, etc.

0x1800 to

0x19FF

3 Inhibit time Word 0 Minimum time between 2 transmissions of the same PDO (pass band occupation)



TxPDO mapping parameter objectsTxPDO mapping parameter objects


Transmit PDO: Index 0x1A00 to 0x1BFFTransmit PDO: Index 0x1A00 to 0x1BFF

Index Sub-Index


Description

0 Number of elements Byte

Depends on

product Number of objects mapped

1 1st object mapped

Double word

Depends on

product

Byte 3 and 2 (most significant bits)=Index Byte 1 = Sub-index Byte 0 = Length in bits Example: 0x64010110

2 2nd object mapped

Double word

Depends on

product


… … … … …

0x1A00 to

0x1BFF

8 8th object mapped

Double word

0 As above



RxPDO communication parameter objectsRxPDO communication parameter objects


Receive PDO: Index 0x1400 to 0x15FFReceive PDO: Index 0x1400 to 0x15FF

Index Sub-Index


Description

0 Number of elements Byte 2 Number of elements following

1 COB-ID Double word

Depends on the PDO

number and the node ID

11 least significant bits = COB-ID Bit 31 = indicates whether the PDO is active or not Bit 30 = indicates whether remote frame access is supported or not.

0x1400 to

0x15FF

2 Transmission

type Byte Depends

on the product

Describes how the PDO received is treated.



RxPDO mapping parameter objectsRxPDO mapping parameter objects


Receive PDO: Index 0x1600 to 0x17FFReceive PDO: Index 0x1600 to 0x17FF

Index Sub-Index


Description

0 Number of elements Byte

Depends on

product Number of objects mapped

1 1st object mapped

Double word

Depends on

product


2 2nd object mapped

Double word

Depends on

product

Byte 3 and 2 (most significant bits)=Index Byte 1 = Sub-index Byte 0 = Length in bits Exemple : 0x62000208

… … … … …

0x1600 to

0x17FF

8 8th object mapped

Double word

0 As above



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

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

PDO transmission modesPDO transmission modes


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



These services are used for the point to point transmission of parameter setting data which is not time critical.

They enable a client device (bus manager) to access the object dictionary of a server device (stations 1 to 127) in write or read mode, by addressing it by its Index and Sub-index.

The size of the data may exceed 8 bytes, in which case a data segmentation system is activated.

The result of a write or read operation is confirmed by a response.

An SDO exchange requires 2 COB-IDs: one for the request, the other for the response.

Service Data Objects = SDOService Data Objects = SDOService Data Objects = SDOService Data Objects = SDO




SYNC = Synchronization Object:

These objects are used to synchronize the acquisition of inputs or updating of outputs (axis control for example).

The "SYNC master" sends the SYNC message at a an interval (communication cycle period) fixed at the time of configuration.

Special Function Objects = SFOSpecial Function Objects = SFOSpecial Function Objects = SFOSpecial Function Objects = SFO




EMCY Object:

EMCY objects are triggered when an internal fault occurs in the device (current, voltage, temperature, communication, etc).





There are 2 mechanisms for monitoring the status of stations on the bus.

Node guarding

This operates on the basis of the master-slave concept (polling), allowing the bus manager to request (remote request) the status of each station at a configurable time interval.

Heartbeat

This operates on the basis of the producer-consumer concept.

The status of the station is generated cyclically at a configurable interval.

This recently-specified mechanism replaces node guarding on new products (better utilisation of the pass band).





Node guard object:

The NMT master monitors the status of slaves connected to the network by periodically sending a Node guard object remote frame to each slave.

Each slave answers immediately on reception.

Slaves have the option of monitoring the NMT master: Life guarding.

Life Time = Guard Time x Life Time Factor

If a slave receives no polling for a period equal to the Life Time, it generates a "Life guarding" event, goes into communication fault mode and sends an EMCY object.






Node guard object:

The NMT master periodically monitors the status of each slave by sending a remote frame and comparing it with the values previously recorded in a table.

If a difference is detected, the information is returned to the application by means of a “network event”.




Heartbeat:

The recently-specified heartbeat function saves on pass band utilisation as compared with node guarding.

The heartbeat producer transmits the heartbeat message at an interval defined in the “Heartbeat producer time” object.

The heartbeat consumer verifies that it has received the heartbeat message within the time window defined in the “Heartbeat consumer time” object.





CANopenCANopen

Section 5: Main characteristics resume



Medium: Shielded twisted pair2 or 4-wire (if power supply)

Topology: Bus type

With short tap links and end-of-line resistor

Maximum distance: 1000 m

Data rate: 9 possible data rates from 10 Kbps to 1 Mbps

Depends on the length of the bus and the type of

cable: 1000 m for 10Kbps, 25 m for 1 Mbps

Max. no. of devices: 1271 master and 126 slaves

Physical LayerPhysical Layer

Section 5 : Main characteristics resume



Network access method: CSMA/CA

Each device can send data as soon as the bus is free.

In the event of a collision, a principle of dominant or recessive bits can arbitrate bit by bit in a non-destructive manner.

The priority of a message is given by the value of the identifier called COB-ID (Communication Object Identifier) located at the beginning of the frame.

The COB-ID is coded on 11 bits: values are between 0 and 2047.

The COB-ID with the lowest value has the highest priority.

Link layerLink layer




Communication model: Producer/ConsumerEach message contains an identifier located at the start of the message.

The identifier value informs receivers as to the type of data contained in each message.

Each receiver decides whether or not to consume the data according to his configuration.

Max. useful data size: 8 bytes per frame

Security of transmission:Among the best on industrial local area networks.Numerous signalling and error detection devices ensure excellent security of transmission.

Link layerLink layer






CANopen defines:

how data is transmitted:

DS-301 communication profile common to all products

Amongst other things this defines the allocation of COB-ID identifiers for each type of message.

what data is transmitted:

DS-4xx product profiles specific to each product family

(discrete I/O, analogue I/O, variable speed drives, encoders, etc.)

These functions are described by means of a Device Object Dictionary (OD) in the form of an EDS file.





4 types of service have been standardised:

1 . Network administration: parameter setting, starting, monitoring (master-slaves)

2 . High-speed transmission of process data (<= 8 bytes):

PDO = Process Data Object (producer-consumer model)

3 . - Transmission of parameter setting data (with segmentation can be > 8 bytes) (not time-critical):

SDO = Service Data Object (client-server model)

4 . Predefined messages for managing synchronisation, time references, fatal errors: SFO = Special Function Object

Documents

Section 2 - Slide 1/61 P&T - GPS - Training PhW - CANopen_lev2_en 10/2004 CANopen CANopen Section 1: History Section 2: Physical layer Section 3: Link