DRAFTSAERECOMMENDEDPRACTICEJ2178CLASSBDATACOMMUNICATIONNETWORKMESSAGESPART1DETAILEDHEADERFORMATS&PHYSICALADDRESSASSIGNMENTS1/5/94THISPAGELEFTBLANKTABLEOFCONTENTSSCOPE1REFERENCEANDRELATEDDOCUMENTS,TERMS,DEFINITIONS,ABBREVIATIONS,ANDACRONYMS3.1ReferenceandRelatedDocuments3.1.1SAEDocuments3.1.2OtherDocuments3.2TermsandDefinitions3.3AbbreviationsandAcronyms6GENERALINFORMATION7.1Part1Overview7.2In-FrameResponseFieldFormats8.2.1In-FrameResponseType08.2.2In-FrameResponseType18.2.3In-FrameResponseType28.2.4In-FrameResponseType38SINGLEBYTEHEADERMESSAGESANDFORMAT10CONSOLIDATEDHEADERMESSAGESANDFORMAT11.1OneByteFormoftheConsolidatedHeaderFormat11.2ThreeByteFormoftheConsolidatedHeaderFormat11.2.1Priority/Type-Byte112.2.1.1Priority(PPPBits)13.2.1.2HeaderType(HBit)13.2.1.3In-FrameResponse(KBit)14.2.1.4AddressingType(YBit)14.2.1.5TypeModifier(ZZBits)15.2.2TargetAddress-Byte216.2.3SourceAddress-Byte316DATAFIELDFORMATS17.1FunctionalDataFieldFormats17.1.1FunctionalDataFieldFormat017.1.2FunctionalDataFieldFormat117.1.3FunctionalDataFieldFormat217.1.3.1TheParameter/QuantityBit(Qbit)18.1.3.2TheControlBit(Cbit)18.1.3.3TheSecondaryAddress20.1.4FunctionalDataFieldFormat320.1.5FunctionalDataFieldFormat420.2PhysicalDataFieldFormats21.2.1PhysicalDataFieldFormat021.2.2PhysicalDataFieldFormat121.2.3PhysicalDataFieldFormat222.3ExtendedAddressing22PHYSICALADDRESSASSIGNMENTS25APPENDIXA1SAEJ2178.PT1i1/5/941SCOPESCOPE:Thisdocumentdefinestheinformationcontainedintheheaderanddatafieldsofnon-diagnosticmessagesforautomotiveserialcommunicationsbasedonSAEJ1850ClassBnetworks.Thisdocumentdescribesandspecifiestheheaderfields,datafields,fieldsizes,scaling,representations,anddatapositionsusedwithinmessages.ThegeneralstructureofaSAEJ1850messageframewithoutin-frameresponseisshowninFigure1below.ThestructureofaSAEJ1850messagewithin-frameresponseisshowninFigure2.Figures1and2alsoshowthescopeofframefieldsdefinedbythisdocumentfornon-diagnosticmessages.RefertoSAEJ1979forspecificationsofemissionsrelateddiagnosticmessageheaderanddatafields.RefertoSAEJ2190forthedefinitionofotherdiagnosticdatafields.Thedescriptionofthenetworkinterfacehardware,basicprotocoldefinition,theelectricalspecifications,andtheCRCbytearegiveninSAEJ1850.<-----SAEJ2178----->SOFHeaderFieldDataFieldCRCbyteEOFFigure1-ScopeofSAEJ2178foraSAEJ1850FramewithoutIn-FrameResponse(IFR)<-----SAEJ2178-----><--SAEJ2178-->SOFHeaderFieldDataFieldCRCbyteEODIFREOFFigure2-ScopeofSAEJ2178foraSAEJ1850FramewithIn-FrameResponse(IFR)SAEJ1850definestwoandonlytwoformatsofmessageheaders.TheyaretheSingleByteheaderformatandtheConsolidatedheaderformat.Theconsolidatedheaderformathastwoforms,asinglebyteformandathreebyteform.ThisdocumentcoversalloftheseformatsandformstoidentifythecontentsofmessageswhichcouldbesentonaSAEJ1850network.Thisdocumentconsistsoffourparts,eachpublishedseparately.Part1ofSAEJ2178(Titled:DetailedHeaderFormats&PhysicalAddressAssignments)describesthetwoallowedformsofmessageheaderformats,singlebyteandconsolidated.Italsocontainsthephysicalnodeaddressrangeassignmentsforthetypicalsub-systemsofanautomobile.SAEJ2178.PT111/5/94Part2ofSAEJ2178(Titled:DataParameterDefinitions)definesthestandardparametricdatawhichmaybeexchangedonSAEJ1850(ClassB)networks.Theparameterscaling,ranges,andtransferfunctionsarespecified.Messageswhichrefertotheseparametricdefinitionsshallalwaysadheretothes...
