Understanding and Using the Controller Area Network Communication Protocol: Theory and Practice

239 Pages·2012·12.131 MB·English

by  Marco Di Natale, Haibo Zeng, Paolo Giusto, Arkadeb Ghosal (auth.)

Understanding and Using the Controller Area
Network Communication Protocol

Marco Di Natale • Haibo Zeng (cid:129) Paolo Giusto
Arkadeb Ghosal
Understanding and Using
the Controller Area Network
Communication Protocol
Theory and Practice
123
MarcoDiNatale HaiboZeng
ScuolaSuperioreS.Anna McGillUniversity
RETISLab. Montreal,Quebec,CanadaH3A2A7
Pisa56124,Italy
ArkadebGhosal
PaoloGiusto NationalInstruments
GeneralMotorsCorporation Berkeley,CA94704,USA
PaloAlto,CA94306,USA
ISBN978-1-4614-0313-5 e-ISBN978-1-4614-0314-2
DOI10.1007/978-1-4614-0314-2
SpringerNewYorkDordrechtHeidelbergLondon
LibraryofCongressControlNumber:2011944254
©SpringerScience+BusinessMedia,LLC2012
Allrightsreserved.Thisworkmaynotbetranslatedorcopiedinwholeorinpartwithoutthewritten
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toproprietaryrights.
Printedonacid-freepaper
SpringerispartofSpringerScience+BusinessMedia(www.springer.com)
Preface
This book is the result of several years of study and practical experience in
the design and analysis of communication systems based on the Controller Area
Network (CAN) standard. CAN is a multicast-based communication protocol
characterizedbythedeterministicresolutionofthecontention,lowcost,andsimple
implementation.TheCAN [16]wasdevelopedinthemid1980sbyBoschGmbH,
toprovideacost-effectivecommunicationsbusforautomotiveapplications.Today
itiswidelyusedalsoinfactoryandplantcontrols,inrobotics,medicaldevices,and
alsoinsomeavionicssystems.
ControllerAreaNetworkisabroadcastdigitalbusdesignedtooperateatspeeds
from 20kbit/s to 1Mbit/s, standardized as ISO/DIS 11898 [6] for high speed
applications(500kbit/s)and ISO 11519-2 [7] for lowerspeed applications(upto
125kbit/s).Thetransmissionratedependsonthebuslengthandtransceiverspeed.
CAN is an attractive solution for embedded control systems because of its low
cost,lightprotocolmanagement,thedeterministicresolutionofthecontention,and
the built-in featuresfor error detection and retransmission. Controllerssupporting
the CAN communication standard, as well as sensors and actuators that are
manufacturedforcommunicatingdataoverCAN,aretodaywidelyavailable.CAN
networksaresuccessfullyreplacingpoint-to-pointconnectionsinmanyapplication
domains.
Commercial and open source implementation of CAN drivers and middleware
softwareistodayavailablefromseveralsources,andsupportforCAN is included
in automotive standards, including OSEKCom and AUTOSAR. The standard has
been developed with the objective of time determinism and support for reliable
communication. With respect to these properties, it has been widely studied by
academiaandindustry,andmethodsand toolshave beendevelopedforpredicting
thetimeandreliabilitycharacteristicsofmessages.
The CAN standard has originally been proposed for application to automotive
systems, but with time emerged as a quite appropriate solution for other control
systems as well. This book tries a general approach to the subject, but in many
placesitreferstoautomotivestandardsandsystems.Automotivearchitecturesand
functionsare also often used as examples and benchmarks. We hope this is not a
v
vi Preface
problemforthereaderandhopefully,thegeneralizationoftheproposedapproaches
andmethodstootherdomainsshouldnotbetoohard.Ontheotherside,automotive
systems are today an extremely interesting context for whoever is interested in
complex and distributed embedded systems (including of course those using the
CAN bus). They offer complex architectures with multiple buses and nodes with
gateways,realtimeandreliabilityconstraintsandallthechallengesthatcomewith
ahighbusutilizationandthedemandforincreasedfunctionalcomplexity.
Thisbookattemptsatprovidinganencompassingviewonthestudyanduseof
theCANbus,withreferencestotheoryandanalysismethods,andadescriptionof
theissuesinthepracticalimplementationofthecommunicationstackforCANand
theimplicationsofdesignchoicesatalllevels,fromtheselectionofthecontroller,
toSW developmentandarchitecturedesign.We believesuchanapproachmaybe
of advantage to those interested in the use of CAN, from students of embedded
system courses, to researchers, architecture designers, system developers, and all
practitionersthatareinterestedinthedeploymentanduseofaCANnetworkandits
nodes.
As such, the book attempts at covering all aspects of the design and analysis
of a CAN communication system. Chapter 1 contains a short summary of the
standard,withemphasisonthebusaccessprotocolandontheprotocolfeaturesthat
are related to or affect the reliability of the communication. Chapter 2 describes
the functionality, the design, the implementation options, and the management
policies of the hardware controllers and software layers in CAN communication
architectures. Chapter 3 focuses on the worst case time analysis of the message
responsetimesorlatencies.Chapters4and5presentsthestochasticandstatistical
timing analyses. Chapter 6 addresses reliability issues. Chapter 7 deals with the
analysis of message traces. Chapter 8 describescommercialtools for configuring,
analyzing and calibrating a CAN communication system. Chapter 9 contains a
summaryofthemaintransportlevelandapplication-levelprotocolsthatarebased
onCAN.
Pisa,Italy MarcoDiNatale
Montreal,QC,Canada HaiboZeng
PaloAlto,CA,USA PaoloGiusto
Berkeley,CA,USA ArkadebGhosal
Contents
1 TheCAN2.0bStandard..................................................... 1
1.1 PhysicalLayer........................................................... 2
1.1.1 BitTiming....................................................... 2
1.1.2 Transceivers,NetworkTopologyandBusLength ............ 6
1.1.3 PhysicalEncodingofDominantandRecessiveStates........ 10
1.1.4 Connectors...................................................... 10
1.1.5 ThePhysicalLayerinISOandSAEStandards............... 11
1.2 MessageFrameFormats................................................ 13
1.2.1 DATAFrame.................................................... 14
1.2.2 RemoteFrame .................................................. 17
1.2.3 ErrorFrame ..................................................... 17
1.2.4 OverloadFrame................................................. 17
1.3 BusArbitration.......................................................... 17
1.4 MessageReceptionandFiltering....................................... 19
1.5 ErrorManagement...................................................... 20
1.5.1 CRCChecks .................................................... 20
1.5.2 Acknowledgement.............................................. 21
1.5.3 ErrorTypes...................................................... 21
1.5.4 ErrorSignalling................................................. 21
1.5.5 FaultConfinement.............................................. 22
2 ReferenceArchitectureofaCAN-BasedSystem......................... 25
2.1 CANControllerandBusAdapter...................................... 27
2.2 CANDeviceDrivers.................................................... 29
2.2.1 Transmission.................................................... 29
2.2.2 Reception........................................................ 31
2.2.3 Bus-OffandSleepModes...................................... 32
2.3 InteractionLayer........................................................ 32
2.3.1 DirectTransmissionMode ..................................... 35
2.3.2 PeriodicTransmissionMode................................... 36
2.3.3 MixedTransmissionMode..................................... 37
vii
viii Contents
2.3.4 DeadlineMonitoring............................................ 38
2.3.5 MessageFiltering............................................... 38
2.4 ImplementationIssues.................................................. 38
2.4.1 DriverLayer..................................................... 39
2.4.2 InteractionLayer................................................ 41
3 Worst-CaseTimeAnalysisofCANMessages............................. 43
3.1 IdealBehaviorandWorst-CaseResponse-TimeAnalysis............ 45
3.2 AnalysisFlawandCorrection.......................................... 48
3.3 AnalysisofMessageSystemsWithOffsets ........................... 50
3.4 MessageBufferingInsidethePeripheral .............................. 51
3.5 AnIdealImplementation ............................................... 52
3.6 SourcesofPriorityInversion:WhentheAnalysisFails............... 57
3.6.1 MessageQueueNotSortedbyPriority........................ 57
3.6.2 MessagesSentbyIndexoftheCorrespondingTxObject..... 57
3.6.3 ImpossibilityofPreemptingtheTxObjects ................... 58
3.6.4 Polling-BasedOutput........................................... 60
3.7 FromtheTimingAnalysisofMessagestoEnd-to-End
Response-TimesAnalysis .............................................. 62
3.8 Conclusions ............................................................. 65
4 StochasticAnalysis........................................................... 67
4.1 Introduction ............................................................. 67
4.2 ReferenceWork......................................................... 69
4.3 SystemModelandNotation............................................ 71
4.4 StochasticAnalysisofMessageResponse-Times..................... 72
4.4.1 AModelingAbstractionforCANMessages.................. 72
4.4.2 StochasticAnalysisoftheApproximateSystem.............. 77
4.5 AnalysisonanExampleAutomotiveSystem ......................... 84
5 StatisticalAnalysis........................................................... 89
5.1 Introduction ............................................................. 89
5.2 DerivingandFittingtheModel......................................... 90
5.2.1 CommonCharacteristicsofMessageResponse-Times....... 91
5.2.2 FittingtheMessageResponse-Times.......................... 93
5.3 EstimateoftheDistributionParameters ............................... 98
5.3.1 Parametersxoffandy........................................... 98
5.3.2 ParametersyD andy(cid:2) ......................................... 98
5.3.3 ParametersaandboftheGammaDistribution............... 100
5.4 PredictingMessageResponse-Times .................................. 108
5.4.1 PredictionofResponse-TimecdfsforMessages
ontheReferenceBus........................................... 110
5.4.2 PredictionofResponse-TimecdfsforMessages
onOtherBuses.................................................. 112
5.5 ComparisonofStochasticandStatisticalAnalyses ................... 117
5.5.1 InputInformation............................................... 117
Contents ix
5.5.2 AnalysisAccuracy.............................................. 118
5.5.3 AnalysisComplexity ........................................... 119
6 ReliabilityAnalysisofCAN................................................. 121
6.1 ErrorRatesinCAN..................................................... 122
6.2 DeviationPointsintheStandard....................................... 124
6.2.1 IncorrectValuesintheDLCField ............................. 124
6.2.2 DominantSRRBitValue....................................... 125
6.3 FaultConfinementandTransitiontoBusOff ......................... 125
6.4 InconsistentOmissionsorDuplicateMessages ....................... 126
6.5 ProtocolVulnerability .................................................. 128
6.6 BusTopologyIssues.................................................... 131
6.7 BabblingIdiotFaultsandBusGuardians.............................. 132
7 AnalysisofCANMessageTraces .......................................... 133
7.1 Notation ................................................................. 134
7.2 CaseStudies............................................................. 134
7.3 TraceAnalysis........................................................... 135
7.3.1 IdentificationofReferenceMessages.......................... 136
7.3.2 BaseRateMessage ............................................. 137
7.3.3 Reconstructionofthe TrueMessage Periods
andArrivalTimes............................................... 137
7.3.4 QueuingJitterBecauseofTxTaskSchedulingDelays........ 139
7.3.5 ClockDriftsandActualMessagePeriods..................... 139
7.3.6 Finding the Message Phase with Respect
totheBaseRateMessage ...................................... 141
7.4 AnalysisofAutomotiveCaseStudies.................................. 142
7.4.1 Overwrite Error at the Destination Node
forMessage0x1F3inV ....................................... 144
1
7.4.2 AperiodicMessageTransmission.............................. 148
7.4.3 LocalPriorityInversion ........................................ 148
7.4.4 RemotePriorityInversion...................................... 152
7.4.5 MessageLossatSourceNode ................................. 153
7.4.6 ReconstructionofMessage-to-ECURelation
inaHybridVehicle ............................................. 155
8 CANTools .................................................................... 157
8.1 SystemConfiguration................................................... 158
8.2 SystemAnalysis......................................................... 160
8.2.1 NetworkBusSimulationandRest-BusSimulation........... 160
8.2.2 TrafficLoggingandAnalysis .................................. 167
8.2.3 NetworkBusWorst/BestCaseAnalysis....................... 169
8.3 ProtocolStackImplementationandConfiguration.................... 175
8.3.1 CANDriverDevelopmentandIntegration.................... 175
8.4 ProtocolStack/ApplicationCalibration................................ 178
x Contents
9 Higher-LevelProtocols...................................................... 181
9.1 J1939 .................................................................... 181
9.1.1 PhysicalLayer .................................................. 182
9.1.2 ParametersandParameterGroups............................. 183
9.1.3 ProtocolDataUnits(PDUs).................................... 185
9.1.4 TransportProtocol.............................................. 186
9.1.5 NetworkManagement.......................................... 188
9.2 CANopen................................................................ 190
9.2.1 CANopenArchitectureandStandards......................... 190
9.2.2 PhysicalLevel................................................... 190
9.2.3 ObjectDictionary............................................... 192
9.2.4 TimeServices................................................... 195
9.2.5 CommunicationProtocols...................................... 197
9.2.6 Service-OrientedCommunicationandSDO .................. 197
9.2.7 MessageIdentifierAllocation.................................. 203
9.2.8 NetworkManagement.......................................... 204
9.3 CCP...................................................................... 206
9.3.1 ProtocolDefinition ............................................. 206
9.3.2 CommandReceiveObject...................................... 207
9.3.3 DataTransmissionObject...................................... 208
9.3.4 ListofCCPCommands ........................................ 208
9.3.5 ListofPacketIDsandCommandReturnCodes.............. 210
9.4 TTCAN.................................................................. 210
9.4.1 MotivationandGoal............................................ 211
9.4.2 SynchronizationMechanismsinTTCAN ..................... 211
9.4.3 SchedulingofTTCANNetworks.............................. 212
9.4.4 ReliabilityofTTCANandAdditionalNotes.................. 214
Symbols ........................................................................... 215
References......................................................................... 217
Index............................................................................... 221