canopen dictionary v7

8/10/2019 CANopen Dictionary v7

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CANdictionary

CAN in Automation e. V.

Kontumazgarten 3

DE-90429 Nrnberg

Tel. +49-911-928819-0Fax [email protected]

Keywords u Technical terms u Standards

20137thedition

Explains vocabulary and abbreviationsused in CAN technology

Covers CAN data link layers, CAN physical layers,and CAN-based higher-layer protocols

Includes a short history ofCAN developments and application fields


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CAN in Automationinternational users and manufacturers group e. V.


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Foreword

This dictionary briefly describes vocabularyand abbreviations used in CAN technology.

It is not supposed to substitute any standardor specification. CAN newcomers may usethe CANdictionary to understand technicalarticles, handbooks, etc. more easily withoutconsulting standards and specifications.

The CAN dictionary covers the CAN datalink layer, CAN physical layer as well asseveral CAN-based higher-layer protocols.The editors have tried to include all relevantinformation. However, users might look forsome entries that the editors have not con-sidered or find entries that may not be suffi-ciently described yet.

With regard to a more comprehensive suc-cessor edition of the CANdictionary, the edi-tors would appreciate comments and pro-


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Introduction

The internationally standardized, serial bus system Con-troller Area Network (CAN) was originally developed for

in-vehicle networking. In 1986, the CAN data link layerprotocol was introduced at the SAE conference in Detroit.In 1993, the CAN protocol and the high-speed physicallayer were internationally standardized as ISO 11898.Today, this ISO standard comprises the following parts:

ISO 11898-1: Data link layer ISO 11898-2: High-speed transceiver

ISO 11898-3: Fault-tolerant transceiver

ISO 11898-4: Time-triggered CAN

ISO 11898-5: High-speed transceiver with low-power mode

ISO 11898-6: High-speed transceiver with selectivewake-up capability (in progress)

The classicCAN data link layer protocol uses one bit-ratefor the entire frame. The recently introduced improvedCAN data link layer protocol (also known as CAN FD)uses for the data-phase a second higher bit-rate, which


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industrial machine control, factory automation, medical

devices, laboratory automation, lift and door control,power energy generation and distribution as well as manyother embedded control systems.The CAN physical layers using differential voltages arerobust against disturbances, and the CAN data link layerprotocol provides a reliable communication featuring aHamming distance of 6 (also for the improvedCAN dataframes). This means, five randomly distributed bit errorsare detected as well as burst-errors with length of 15 bit.

The higher-layer protocols and profiles support interoper-ability of devices up to the level of off-the-shelf plug-and-play.


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A

acceptancefilter

The acceptance filter in CAN controllerchips is used to select messages thatare received depending on the as-

signed identifier. Most of the CAN con-troller chips provide a hardware ac-ceptance filter that filters CAN messag-es assigned with a specific identifier ora range of identifiers. The user-settable

filter unburdens the micro-controllerfrom the task of acceptance filtering.

acknowledge(ACK) delimit-

er

The second bit of the acknowledgefield. It is by definition recessive. The

dominant state of this bit is regarded asa form error and causes the transmis-sion of an error frame.

acknowledge

error

If the message-transmitting node de-

tects the recessive state in theacknowledge slot, it regards that asacknowledge error condition.Acknowledge errors do not cause to


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application

layer

The application layer is the communica-

tion entity of the OSI (Open SystemInterconnect) reference model. It pro-vides communication services to theapplication program.

applicationobjects

Application objects are signals andparameters of the application programvisible at the application layer API (ap-plication programming interface).

applicationprofile

Application profiles define all communi-cation objects and application objects inall devices of a network.

arbitration field The arbitration field is made of the 11-bit or 29-bit identifier, the RTR (remotetransmission request) bit, and in case ofthe 29-bit format also of the IDE (identi-fier extension) bit, and the SRR (substi-

tute remote request) bit.

arbitrationphase

The arbitration phase indicates thoseparts of the improved CAN data frame


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placeable units (LRUs). This specifica-

tion is intended for avionic programma-ble devices.

assemblyobject

This DeviceNet object describes thecontent of the I/O message.

asynchronousPDO

Asynchronous PDO is the historicalterm for event-driven PDO.

automatic re-transmission Corrupted messages (data frames andremote frames) are retransmitted auto-matically after the error frames are suc-cessfully transmitted.

auto bit ratedetection

The CAN node listens only to the bustraffic, and when a valid message isdetected, it acknowledges the receivedframe. If no valid message is detected,the CAN node switches automatically to

the next pre-configured bit-rate. Therehas to be one and only one node in thenetwork that transmits messages.Some CAN controller chips support


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B

bandwidth The bandwidth is the value, which de-nominates the size of informationtransmitted in a defined time unit.

BasicCAN A term used in the early days of CANdescribing an implementation, whichuses just two receive message buffersfilled and read out in a ping pong meth-

od.

base frameformat

The base frame format uses 11-bitidentifiers in data frames as well asremote frames.

basic cycle In TTCAN the basic cycle starts alwayswith the reference message followed bya number of exclusive, arbitration orfree windows. One or more basic cycles

make the TTCAN matrix cycle.

bit encoding In CAN, the bits are encoded as non-return to zero coding (NRZ)


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bit rate switch At the sample point of the bit rate switchbit in improved CAN data frames, thedata phase starts. This means at thesample point of the bit rate switch bitthe CAN controllers may switch to ahigher bit rate. The bit rate switch bitexits in improved CAN data framesonly.

bitresynchroniza-tion

Due to local oscillator tolerances it mayhappen that one node loses the bitsynchronization. Each recessive-to-dominant edge causes the CAN control-ler to resynchronize itself to the re-

ceived falling edge.

bit stuffing Injections of bits into a bit stream toprovide bus state changes that arerequired for periodic resynchronization.

bit time Duration of one bit.

bit-timing The setting of the bit-timing registers in


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bus access When the bus is idle, any node maystart to transmit a frame. In CAN net-works the nodes access the bus bytransmitting the dominant SOF (start offrame) bit.

bus analyzer Tool, which monitors the bus and dis-plays the transmitted bits. Bus analyz-ers are available for the physical layer,

the data link layer, and different applica-tion layers (e.g. CANopen or De-viceNet).

bus arbitration If at the very same moment several

nodes try to access the bus, an arbitra-tion process is necessary to controlwhich node may transmit while the oth-er nodes have to delay their transmis-sion. The bus arbitration process used

in CAN protocol is CMSA/CD (CarrierSense Multiple Access/Collision Detec-tion) with AMP (Arbitration on MessagePriority) This allows bus arbitration


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bus length The network cable length between thetwo termination resistors. The buslength of CAN networks is limited by theused transmission rate. At 1 Mbit/s themaximum length is theoretically 40 m.When using lower transmission rates,longer bus lines may be used: at 50kbit/s a length of 1 km is possible.

busload The busload is the ratio of transmittedbits to bus idle bits within a defined timeunit. Where 100% means that bits aretransmitted during the complete definedtime unit and 0% means that the bus is

in bus idle state during the completedefined time unit.

bus monitoringmode

In this mode, the CAN controller hasswitched off the Tx pin. This means no

error flag or no ACK slot can be trans-mitted.

bus-off state The CAN controllers switch to bus-off


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C

CAN Controller Area Network (CAN) is aserial bus system originally developedby the Robert Bosch GmbH. It is inter-nationally standardized by ISO 11898-1. CAN has been implemented by manysemiconductor manufacturers.

CANaero-

space

Higher-layer protocol for avionic and

aerospace applications.

CANApplicationLayer (CAL)

Application layer developed by CiA(CAN in Automation) members provid-ing several communication services and

corresponding protocols.

CAN commonground

Each CAN network requires a commonground that avoids common mode re-

jection problems. However, there is a

chance that there are unwanted loopcurrents via ground potential.

CAN device Hardware module providing at least one


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CAN identifier The CAN identifier is the main part of

the arbitration field of a CAN data frameor CAN remote frame. It comprises 11bit (base frame format) or 29 bit (ex-tended frame format) and indicatescertain information uniquely in the net-work. The CAN identifier value deter-mines implicitly the priority for the busarbitration.

CAN inAutomation(CiA)

The international users' and manufac-turers' group founded in 1992 promotesCAN and supports CAN-based higher-layer protocols (www.can-cia.org).

CAN Kingdom Higher-layer protocol framework opti-mized for deeply embedded networks.In particular, it is suitable for real-timeapplications.

CAN_L Indicates the CAN low line in CAN-based networks. The CAN_L line of ISO11898-2 compliant transceiver is inrecessive state on 2 5 V and in domi-


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CANopen

applicationlayer

The CANopen application layer and

communication profile (CiA 301) isstandardized by EN 50325-4. It definescommunication services and objects. Inaddition, it specifies the object diction-ary and the network management(NMT).

CANopen Lift Unregistered trademark for the CiA 417application profile for lift control sys-

tems.CANopenmanager

The CANopen manager is responsiblefor the management of the network. Inthe CANopen manager device, there

resides the NMT (network manage-ment) master functionality. Additionally,there may reside the SDO (service dataobject) manager or/and the configura-tion manager. A CANopen manager

owns a CANopen object dictionary andsupports also CANopen NMT slavefunctionality.


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CAN trans-

ceiver

The CAN transceiver is connected to

the CAN controller and to the bus lines.It provides the line transmitter and thereceiver. There are high-speed, fault-tolerant, and single-wire transceiversavailable as well as transceivers forpower-line or fiber optic transmissions.

CCP The CAN Calibration Protocol (CCP) isused to communicate calibration data in

engine car applications.certification Official compliance test of components

or devices to a specific standard. TheC&S group performs conformance test-

ing of CAN controller chips. ODVA offi-cially certifies DeviceNet products, andCiA officially certifies CANopen devices.

CiA 102 Additional physical layer specification

for high-speed transmission accordingto ISO 11898-2 using 9-pin D-sub con-nectors.


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CiA 303 Recommendation for CANopen cabling

and connector pin assignments, codingof prefixes and SI units as well as LEDusage.

(CiA 304) See EN 50325-5.

CiA 305 The layer setting services (LSS) specifyservices and protocols to set the node-ID or the bit rate via the CANopen net-

work in a master/slave-based commu-nication.

CiA 306 This specification defines format andcontent of Electronic Data Sheets

(EDS) of CANopen devices to be usedin configuration tools.

CiA 308 The CANopen technical report definestime measurements such as PDO turn-

around time, Sync jitter, and SDO re-sponse time. Additionally it definesstandard busloads.


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scribing device profiles and communi-

cation network profiles for devices usedin CANopen based control systems.

CiA 312 The set of CANopen device profile con-formance test plans specifies all teststeps required for checking, whetherthe implementation of a CANopen de-vice is compliant to the correspondingCANopen device profile.

CiA 313 This set of CANopen profiles specifiestest steps for CANopen performancetesting as well as a pro forma compli-ance template.

CiA 314 CANopen framework for PLCs andother programmable devices compliantto IEC 61131-3.

(CiA 400) See CiA 302.

CiA 401 The CANopen device profile for genericI/O modules covers the definition of


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incremental and absolute, linear and

rotary encoders.

(CiA 407) See EN 13149-4/5/6.

CiA 408 The CANopen device profile for hydrau-lic controllers and proportional valves iscompliant to the bus-independentVDMA (Verband Deutscher Maschinen-und Anlagenbau e.V.) device profile

fluid power technology proportionalvalves and hydrostatic transmission.

CiA 410 The CANopen device profile for incli-nometer supports 16-bit as well as 32-

bit sensors.

CiA 412 The CANopen device profiles for medi-cal equipment specify the interfaces forx-ray collimators and dosimeter devic-

es.

CiA 413 The CANopen interface profiles specifygateways to SAE J1939 ISO 11992


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CiA 417 The CANopen application profile for lift

control specifies the interfaces for carcontrollers, door controllers, call control-lers and other controllers as well as forcar units, door units, input panels, anddisplay units, etc.

CiA 418 The CANopen device profile for batterymodules specifies the interface tocommunicate with battery chargers.

CiA 419 The CANopen device profile for batterycharger specifies the interface to com-municate with the battery module.

CiA 420 The CANopen profile family for extruderdownstream devices defines interfacesfor puller, corrugator and saw devices.

CiA 421 The CANopen application profile for

train vehicle control systems defines thecommunication between virtual controlsystems (e.g. for door control, dieselengine control or control of auxiliary


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faces for contrast media injectors and

electrocardiogram units. CiA 425 is alsoused as unregistered trademark.

CiA 426 The CANopen application profile for railexterior lighting defines the communica-tion between an exterior lighting control-ler and the related exterior lightingunits.

CiA 430 The CANopen application profile for railauxiliary operating systems defines thecommunication between auxiliaryequipment such as power train coolingunit, coolant exposition tank, engine

pre-heating unit or battery charger.

CiA 433 The CANopen application profile for railinterior lighting systems defines thecommunication between an interior

lighting controller and interior lightingunits.

CiA 434 This set of CANopen device profiles


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CiA 443 The CANopen device profile for SIIS

level-2 devices specifies simple andcomplex sensors and actuators. Thisequipment is also known as Christmastree.

CiA 444 The CANopen application profile de-fines the CANopen interfaces for con-tainer-handling machine add-on devicessuch as e.g. spreaders for cranes orstraddle carriers.

CiA 445 This device profile defines the CANo-pen interface for simple and intelligent

radio frequency identification (RFID)devices.

CiA 446 The CANopen device profile for AS-Interface gateways describes CANopen

devices, which act as an AS-Interfacemaster in AS-Interface networks.

CiA 447 The CANopen application profile for


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AC/AC, DC/DC, AC/DC and DC/AC

converters. It is suitable for program-mable and non-programmable powersupply devices with single or multipleoutputs that are voltage-, current- orpower-controlled.

CiA 454 The CANopen application profile forenergy management systems specifiesthe communication interface for all vir-tual devices that may take part in ener-gy management control applications.Such energy control applications maybe implemented in e.g. light electricvehicles, industrial robots, offshore

parks, isolated farms, etc.

CiA 455 The CANopen application profile fordrilling machines specifies the controlling of drilling machines with special

regard on positioning and tool control.

CiA 456 The CANopen device profile for config-urable network components specifies


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frames by other CANopen communica-

tion services.

CiA 808 This application note describes therecommended practice as well as appli-cation hints for development of the

communication between crane andspreader, designed according to thedevice profile CiA 444.

CiA 809 This application note provides imple-mentation and user guidelines for de-vices programmable in IEC 61131-3languages, which communicates toCANopen devices. This includes a de-

scription of the programming and net-work configuration environments.

CiA 810 This application note describes therecommended practice as well as appli-

cation hints for development of the la-boratory automation slave devices,designed according to the device profileCiA 434


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CleANopen Unregistered trademark for the CiA 422

application profile for municipal vehi-cles.

Client SDO The Client SDO initiates the SDO com-munication by means of reading or

writing to the object dictionary of theSDO server device.

client/servercommunication

In a client/server communication theclient initiates the communication withthe server. It is always a point-to-pointcommunication.

COB See communication object.

COB-ID The COB-ID is the object specifying theCAN identifier and additional parame-ters (valid/-invalid bit, remote framesupport bit, frame format bit) for the

related communication object.

communicationobject (COB)

A communication object consists of oneor more CAN messages with a specific


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conformance

test plan

Definitions of test cases that have to be

passed successfully in order to achieveconformance to a communicationstandard. The conformance test plan forCAN is standardized by ISO 16845.

conformancetest tool

A conformance test tool is the imple-mentation of a conformance test plan.

connector Electro-mechanical component used tomake a connection between a deviceand the CAN bus-line or to extend buscables. The connector pin-assignmentfor CAN is specified by CiA for CANand CANopen and by ODVA for De-

viceNet.

consumer In CAN networks a receiver of messag-es is called a consumer meaning theacceptance filter is opened.

content-basedarbitration

Carrier Sense Multiple Access (CMSA)arbitration procedure where simultane-ous access of multiple nodes results in


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CRC field The CRC field in data and remote

frames contains the 15-bit CRC se-quence and the 1-bit CRC delimiter.The CRC sequence is able to detect 5randomly distributed bit failures in SOF,arbitration, control, data fields, or a

burst failure of up to 15 bits. The Ham-ming distance is specified as 6, notconsidering stuff-bits. In the improvedCAN data frames the CRC is sequenceis different depending on the length ofthe data field. The Hamming distance isalso specified as 6, but considers thestuff-bits.

CSMA/CD +AMP The Carrier Sense Multiple Ac-cess/Collision Detection with Arbitrationon Message Priority is the bus arbitra-tion method used in CAN. This methodarbitrates simultaneous bus access

requests.

cyclic redun-dancy check

The cyclic redundancy check (CRC) isperformed by a polynomial implement-


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Ddata con-sistency

With regard to network technologies,data consistency means that all devic-es, which are connected to the samenetwork, have the same state of

knowledge. Network-wide data con-sistency is guaranteed for all error ac-tive CAN nodes by means of globaliza-tion of local errors.

data field The data field of the CAN data framecontains 0 to including 8 byte of userinformation as indicated by the DLC.

data frame The CAN data frame carries data froma producer to one or more consumers.It consists of the start of frame bit, thearbitration field, the control field, thedata field, the CRC field, the

acknowledge field, the end of framefield.

data length The 4-bit DLC in the control field of the


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DBT The Distributor is part of the CAN Appli-

cation Layer (CAL) specification defin-ing a method of automatic identifierdistribution during boot-up of the net-work.

DCF See device configuration file.

default value Object attribute in CANopen definingthe pre-setting of not user-configured

objects after power-on or applicationreset.

device configu-ration file

(DCF)

The device configuration file describesthe CANopen parameter of a configured

CANopen device in the same file formatas the EDS.

DeviceNet CAN-based higher-layer protocol anddevice profiles definition. DeviceNet

was designed for factory automationand provides a well defined CAN physi-cal layer in order to achieve a high off-the shelf plug and play capability The


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0. A dominant bit overwrites by defini-

tion a recessive bit.

double-reception ofmessage

If the last bit of the end of frame (EOF)is corrupted at the transmitting node,then a retransmission of the message is

caused. Since the receivers have al-ready accepted the message after thelast but one bit, they will receive themessage twice.

DR (draftrecommenda-tion)

This kind of recommendation is notfixed, but it is published. CiA!s draftrecommendations are not changedwithin one year.

DS (draftstandard)

This kind of standard is not fixed, but itis published. CiA!s draft standards arenot changed within one year.

DSP (draftstandard pro-posal)

This kind of standard is a proposal, butit is published. CiA!s draft standardproposals may be changed anytimewithout notification


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EEDL See extended data length.

EDS See electronic data sheet.

EDS checker Software tool that checks the conformityof electronic data sheets. The CANopenEDS checker is available on CiA!s web-site to be downloaded.

EDS generator Software tool that generates electronicdata sheets (available for CANopen andDeviceNet).

electronic datasheet (EDS) The electronic data sheet describes thefunctionality of a device in a standard-ized manner. CANopen and DeviceNetuse different EDS formats.

Emergency Pre-defined communication service inCANopen mapped into a single 8-bytedata frame containing a 2-byte stand-ardized error code the 1-byte error


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application layer and communication

profile. The CANopen Safety protocol isdesigned to allow safety-related com-munication based on CAN according toIEC/EN 61508. It is approved by Ger-man authorities and fulfils the require-

ments to build systems requiring SIL 3according to IEC 61508.

entry category This is the object attribute in CANopendefining this object as mandatory oroptional.

end of frame(EOF)

Seven recessive bits make the EOFfield of CAN data and remote frames.

error activestate In error active state the CAN controlleris allowed to transmit active errorframes containing active error flags. Ifall CAN nodes are in this state, than anetwork-wide data consistency is guar-

anteed.

error code CANopen specifies error codes trans-mitted in emergency messages


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error delimiter Last segment in error frames made upof 8 recessive bits.

error detectioncapability

There are five different mechanisms inthe CAN protocol to detect failures,

which allows the detection of nearly anyerror in a CAN message. The probabil-ity of non-detected failures depends onerror rate, bit rate, busload, number ofnodes and error detection capabilityfactor.

error flag First segment in error frames made upof 6 bits of the same polarity. A second

error flag transmitted by another nodemay overlap the first error flag.

error frame Frame to indicate the detection of anerror. It is made up of the error flag and

the error delimiter.

errorglobalization

Local failures cause the transmission ofan error flag which will be regarded as


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ESI See error state indicator.

event-driven Event-driven messages are transmittedwhen a defined event occurs in thedevice. This may be a change of inputstates, elapsing of a local timer, or any

other local event.

event-drivenPDO

An event-driven PDO is transmittedwhenever a device internal event oc-curs. This event may be the elapsing ofthe PDO!s event timer. If an event-driven PDO is received the protocolsoftware immediately updates themapped objects in the object dictionary.

event timer The event timer is assigned in CANo-pen to one PDO. It defines the frequen-cy of PDO transmission.

expeditedSDO This is a confirmed communicationservice of CANopen (peer-to-peer). It is

made up by one SDO initiate messageof the client node and the correspond-


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Ffaultconfinement

CAN nodes are able to distinguish shortdisturbances from permanent failures.Defective transmitting nodes areswitched off, meaning the node is logi-

cally disconnected from the network(bus-off).

fault-toleranttransceiver

Transceivers as specified in ISO 11898-3 and ISO 11992-1 are capable ofcommunication via one bus-line andCAN ground when one bus-line is bro-ken down, short circuited or terminationresistors are not well connected.

finite stateautomaton(FSA)

An FSA is an abstraction to describethe behavior of a black box. It is com-posed of a several states, transitionsbetween those states, and actions.

flying master In safety-critical applications, it may berequired that a missing NMT master issubstituted automatically by another


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bit identifiers and the extended frame

format using 29-bit identifiers.

frame types In CAN, four frame types are used: dataframe, remote frame, error frame, andoverload frame.

FSA See finite state automaton.

FullCAN A term used in the early days of CANdescribing an implementation, whichfeatures single receive and transmitbuffers for a number of IDs.

function code First four bits of the CAN identifier in the

CANopen pre-defined identifier set indi-cating the function of the communica-tion object (e.g. TPDO_1 or error con-trol message).


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Ggalvanicisolation

Galvanic isolation in CAN networks isperformed by optocouplers or trans-formers placed between CAN controllerand CAN transceiver chip.

gateway Device with at least two network inter-faces transforming all seven OSI (opensystem interconnection) protocol layers,e.g. CANopen-to-Ethernet gateway orCANopen-to-DeviceNet gateway.

global error A global bus error affects all connectedCAN devices.

global fail-safecommand

The global fail-safe command (GFC) isa high-priority CAN message defined inthe CANopen safety protocol. It reducesthe reaction time. It shall be followed by

the related SRDO.


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Hhammingdistance

In general, the hamming distance be-tween two strings of equal lengthmeasures the number of errors thattransformed one string into the other.

CAN provides a hamming distance of 6(theoretical value for CAN networks).This indicates that five randomly dis-tributed bit failures can be detected. Inaddition burst errors of up to 15 bit canbe detected. CAN provides no bit cor-rection mechanisms.

hard

synchroniza-tion

All CAN nodes are internally hard syn-

chronized to the falling edge of the SOFbit detected on the bus. Hard synchro-nization is performed during bus idle,suspend transmission and the secondor third bit of interframe space.

heartbeat CANopen and DeviceNet use theheartbeat message to indicate that anode is still alive This message is


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Iidentifier In general, the term refers to a CAN

message identifier. See CAN identifier.

identifier

extension flag(IDE)

The IDE bit indicates if the following bits

are interpreted as control bits or thesecond part of the 29-bit identifier.

identifier field The identifier field contains 11 bits inbase frame format, and additional 18bits in extended frame format.

IEC 61162-3 IEC standard for Digital interfaces fornavigational equipment within a ship.

Part 3 standardizes the Serial datainstrument network, also known asNEMA 2000.

IEC 61800-7-

1/2/3

International standard specifying multi-

ple power drive profiles including CiA402 and CIP motion. The CiA 402 pro-file mapping to CANopen and the CIPmotion profile mapping to DeviceNet


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a transmission of the PDOs and Emer-

gency messages.

initializationstate

NMT slave state in CANopen that isreached automatically after power onand communication or application reset.

inner priorityinversion

If a low-prior message can not betransmitted because of high-prior mes-sage traffic on the CAN network and ahigh-prior transmission request occursin the device and cannot be passed tothe CAN controller due to the still pend-ing low-prior transmission request is

called inner priority inversion.interfaceprofile

CANopen profile that describes just theinterface and not the application behav-ior of a device, e.g. gateway devices.

interframespace

Three recessive bits make up the inter-frame space that separates all CANframes including error and overload


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ISO 11898-4 International standard defining a time-

triggered communication protocolbased on the classic CAN data linklayer protocol.

ISO 11898-5 International standard defining ISO

11898-2 compliant transceivers featur-ing low-power functionality.

ISO 11898-6 International standard defining ISO11898-2 and ISO 11898-5 compliant

transceivers featuring selective wake-up functionality. This means the trans-ceiver supports partially the CAN datalink layer protocol interpreting the CAN-ID and the data field.

ISO 11992 International standard defining a CAN-based application profile for truck/trailercommunication. Part 2 specifies the

brake and gearing devices, part 3specifies other devices, and part 4 de-fines the diagnostics.


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JJ1939applicationprofile

The application profile defined by SAE(www.sae.org) specifies the in-vehiclecommunication in trucks and buses. Itdefines the communication services as

well as the signals including the map-ping into CAN data frames by means ofPGNs (parameter group numbers).

J2284 bit-timing

Bit-timing definitions by SAE for in-vehicle networks in passenger cars for250 kbit/s and 500 kbit/s.

J2411 single-

wire CAN

Single-wire transmission specification

by SAE for CAN networks. The bit rateis limited to40 kbit/s.


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Llayer-2protocol

A layer-2 protocol uses the CAN com-munication services directly without adedicated higher-layer protocol.

layer-7protocol

A layer-7 protocol uses CAN communi-cation services in a standardized man-ner. This allows the reuse of applicationsoftware without redesigning the CANcommunication software.

layer settingservices (LSS)

The CANopen layer setting servicesdefine communication services for con-figuring node-ID and bit rate via the

CAN network.life guarding Method in CAL and CANopen to detect

that the NMT master does not guard theNMT slave anymore. This is part of the

error control mechanisms.

line topology Networks, where all nodes are con-nected directly to one bus line CAN


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low-power

mode

CAN controller and CAN transceiver

may support a stand-by mode requiringlower power than in active mode.

low-speedtransceiver

Synonym for fault-tolerant transceivers.

LSS See layer setting services.


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MMAC See medium access control.

master Communication or application entitythat is allowed to control a specific func-

tion. In networks this is for example theinitialization of a communication ser-vice.

master/slave

communication

In master/slave communication systemthe master initiates and controls thecommunication. The slave is not al-lowed to initiate any communication atall.

matrix cycle In TTCAN the matrix cycle is made upof one or more basic cycles. Each basiccycle starts with the reference messagebut may be followed by different win-

dows.

MDI See medium dependent interface.


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message

doubling

See double reception of message.

MilCAN These CAN-based higher-layer proto-cols have been defined by a group ofinterested companies and government

bodies associated with the specifica-tion, manufacture and test of militaryvehicles. MilCAN A is based on J1939,and MilCAN B is based on CANopen.

MPDO See multiplex PDO.

multicasttransmission

Addressing, where a single frame isaddressed to a group of nodes simulta-neously.

multi-mastercommunication

In a multi-master communication sys-tem every node may temporarily controlthe bus communication. This means

every node has theoretically the right toaccess the bus at any time when thebus is in idle state.


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Nnetwork-ID In multiple CANopen network systems

this identifier identifies a single CANo-pen network uniquely. CANopen sup-ports up to 127 networks in hierarchical

or non-hierarchical network systems.

network length See bus length.

network

management

Entity responsible for the network boot-

up procedure and the optional configu-ration of nodes. It also may includenode-supervising functions such asnode guarding.

networkvariables

Network variables are used in pro-grammable CANopen devices to bemapped into PDOs after programmingthe device.

NMEA 2000 This is a combined electrical and dataspecification for a marine data networkfor communication between marine


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NMT state machine implemented in

CAL and CANopen devices.

NMT slavestatemachine

The NMT slave state machine definedin CAL and CANopen supports differentstates and the highest prior CAN mes-

sage transmitted by the NMT mastercontrols the transition to the states.

node Assembly, linked to the CAN network,capable of communicating across the

network according to the CAN proto-cols.

node guarding Mechanism used in CANopen and CALto detect bus-off or disconnected devic-es, which is part of the error controlmechanisms. The NMT master sends aremote frame to the NMT slave that isanswered by the corresponding error

control message.

node-ID Unique identifier for a device requiredby different CAN-based higher-layer


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Oobjectdictionary

The object dictionary is the heart of anyCANopen device. It enables access toall data types used in the device, to thecommunication parameters, as well as

to the process data and configurationparameters.

open systeminterconnec-

tion (OSI)referencemodel

Layered communication model definingseven layers: physical, data link, net-

work, transport, session, presentation,and application layer. In CAN-basednetworks normally just physical, datalink, and application layer are imple-mented.

operationalstate

Part of the CANopen NMT slave statemachine. In the NMT operational stateall CANopen communication services

are available.

OSEK/VDX Set of specifications for communication(COM) network management (NM)


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overloaddelimiter Last segment in overload frames madeup of 8 recessive bits.

overload flag First segment in overload frames madeup of 6 bits of dominant value. A se-

cond overload flag transmitted by an-other node may overlap the first over-load flag.

overload frame Frame to indicate an overload condi-

tion.


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Pparameter

group (PG)In J1939, ISO 11783, and ISO 11992,there are defined parameter groups,which specify the content of a specificCAN message.

parametergroup number(PGN)

The parameter group number identifiesuniquely the parameter group (PG). ThePGN is mapped into the 29-bit identifier.

passive errorflag

The passive error flag is the first part ofthe passive error frame made up of sixconsecutive recessive bits.

PDO See process data object.

PDO mapping In PDOs, there may be mapped up to64 objects. The PDO mapping is de-scribed in the PDO mapping parame-

ters.

pendingtransmission

There are one or more messages wait-ing for transmission in the CAN control-


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and electrical or optical signals repre-

senting a bit value as well as synchro-nization and re-synchronization.

physicalsignaling

(PLS)

Sub-layer of the physical layer. It re-ceives from and sends to the transceiv-

er circuitry the bit stream and performsthe bit en-/decoding, controls the bit-timing and synchronization.

pin assignment Definition of the usage of connector

pins.

PLS See physical signaling.

pre-definedconnection set

Set of CAN identifiers used as defaultvalues for different communication pro-tocols in CANopen or DeviceNet.

pre-operational

state

Part of the NMT slave state machine. In

the NMT pre-operational state no CAN-open PDO communication is allowed.

priority Attribute to a frame controlling its rank-


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protocol Formal set of conventions and rules forthe exchange of information betweennodes, including the specification offrame administration, frame transferand physical layer.

priorityinversion

Priority inversion occurs if the lowerprior object will be processed or com-municated before the higher prior ob-

ject. In not well-designed CAN devices,

there may occur inner or outer priorityinversions.


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Rreceive error

counter (REC)CAN controller internal counter for re-ception errors. The REC value is read-able in some controllers.

receive PDO The receive process data object(RPDO) is a PDO that is received by aCANopen device.

receiver A CAN node is called receiver or con-

sumer, if it is not transmitted and thebus is not idle.

receptionbuffer(s)

Local memory in the CAN controller,where the received messages arestored intermediately.

recessive bit Bit on the CAN bus lines representingrecessive state. It has the logical value

1.recessive state By definition, the recessive state will be

overwritten by the dominant state


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frame DLC. The data field of the remote

frame has a length of 0 byte.remotetransmissionrequest (RTR)

Bit in the arbitration field indicating if theframe is a remote frame (recessivevalue) or a data frame (dominant val-

ue).

repeater Passive component that refreshes CANbus signals. It is used to increase themaximum number of nodes, to achieve

longer networks (>1 km) or to imple-ment tree or meshed topologies.

reset A CAN controller is reset by a com-mand (may be hard-wired). Before theCAN controller transits back to erroractive state, it has to detect 128 by 11consecutive recessive bit-times.

resetapplication This NMT command resets all objectsin CANopen devices to the default val-ues or the permanently stored config-ured values


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SSafetyBus p This CAN-based higher-layer protocol

and implementation specification by theSafety Network International e. V. isdedicated for safety-related communi-

cation within factory automation. Itmeets the Safety Integrity Level (SIL) 3according to IEC 61508.

sample point The sample point is the point of time at

which the bus level is read and inter-preted as the value of the respective bit.Its location is between Phase_Seg 1and Phase_Seg 2.

safe-guardcycle time(SCT)

The safe-guard cycle time (SCT) de-fines the maximum time between twoperiodically transmitted SRDOs.

safety-relatedobjectvalidation time(SRVT)

The safety-related object validation timedefines the maximum time between thetwo CAN messages that make anSRDO

id th d th


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resides on the very same node as the

NMT master functionality.SDO networkindication

This function is used to address a re-mote CANopen device in another CAN-open network. This service and protocol

establish a virtual channel in order toperform any SDO communication.

segmentedSDO

If objects longer than 4 byte are trans-mitted by means of SDO services, a

segmented transfer is used. The data istransmitted in segments of up to 7 Byteof application data. The number ofsegments is theoretically not limited.

server SDO The server SDO receives the SDOmessages from the corresponding clientand responses each SDO message ora block of SDO messages (SDO block

transfer).service dataobject (SDO)

The SDO is a confirmed communicationservice that provides access to all en-

sleep mode CAN controller and transceiver may be


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sleep mode CAN controller and transceiver may be

operated in stand-by or low-powermode not more driving the bus lines.

SOF See start of frame.

SRDO See safety-relevant data object.

SRR See substitute remote request.

SRVT See safety-related object validation

time.

start of frame(SOF)

The very first bit of any data and remoteframes. The SOF's state is always dom-inant.

star topology In some passenger cars, CAN networksare installed in a star topology terminat-ing the network in the center of the star.

stopped state Part of the NMT slave state machine. Inthe NMT state only NMT messages areperformed and under some conditions

substitute Bit in the extended frame format substi


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substitute

remote request(SRR)

Bit in the extended frame format substi-

tuting the RTR bit after the first part ofthe identifier (11 bit). The SRR's state isrecessive.

suspend

transmission

CAN controllers in error passive mode

have to wait additional 8 bit-times be-fore the next data or remote frame maybe transmitted.

SWC See single-wire CAN.

SYNC counter The optional parameter SYNC counteris used in CANopen networks to definean explicit relationship between thecurrent SYNC cycle and PDO transmis-sion.

SYNCmessage

Dedicated CANopen message forcingthe receiving nodes to sample the in-

puts mapped into synchronous TPDOs.Receiving this message causes thenode to set the outputs to values re-ceived in the previous synchronous


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TTEC See transmit error counter.

terminationresistor

In CAN high-speed networks with busline topology, both ends are terminated

with resistors (120 #) in order to sup-press reflections.

thick cable The thick cable is specified in the phys-ical layer definitions of the DeviceNet

specification. This cable is used fornetworks longer than 100 m.

thin cable The thin cable is specified in the physi-cal layer definitions of the DeviceNetspecification. This cable is used fordrop lines and networks shorter than100 m.

time message Standardized message in CANopencontaining the time as a 6-byte valuegiven as ms after midnight and daysafter 1st January 1984


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TPDO See transmit PDO.transmissionbuffer(s)

Local memory in the CAN controller,where the message to be transmitted isstored.

transmissionrequest

Internal event in the CAN controller totransmit a message.

transmission

time capture

In TTCAN level 2 it is required to cap-

ture the time when the SOF bit of theReference message has been transmit-ted.

transmission

type

CANopen object defining the schedul-

ing of a CANopen communication ob-ject such as e.g. PDO.

transmit errorcounter (TEC)

CAN controller internal counter fortransmission errors. The TEC value isreadable in some controllers.

transmit PDO The transmit process data object is a

networks The CAN controllers have to


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networks. The CAN controllers have to

be capable of switching-off automaticretransmission of faulty messages andmay be able to capture a 16-bit timervalue at SOF transmission in order totransmit the timer value in the very

same message.


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Vvalue definition Detailed description of the value range

of a variable in CANopen profiles.

value range Object attribute in CANopen defining

the allowed values supported by thisobject.

W

wake-up

procedure

This procedure is used to wake-up CAN

transceiver or CAN module that are insleep mode.


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