TECHNOLOGIESARINC664/AFDX®EDEsupportMX-Foundation4APIMAXIMAIRGUIVersion2.12…….…>…TableofContentsI-AFDX/EDE.....................................................................................3I-1.AFDXframelayout............................................................................................3I-2.EDEMessageformat……………………………….…………………………5II-MX-Foundation4-API.............................................................................7II-1.WorkwithAFDXonMX-Foundation4................................................................7II-2.WorkwithAFDX-EDEonMX-Foundation4.......................................................9II-2.a.EDEsupportinAFDXCOMmode.................................................10II-2.b.EDEerrordetectionsupportinAFDXCOMmode…………12II-2.c.EDEsupportinRawmode……………………………………13III-MAXIMAIR....................................................................................14Conclusion....................................................................................................15PAYLOADUDPPAYLOADIPUDPPAYLOADMACheaderIPUDPPAYLOADMACfooter3I-AFDX/EDEAFDXisanavionicsprotocolsupportedbyMAXTechnologies.AFDXisaprotocoloverEthernetwithaddedsecuritytoavoiddatacollisionsandreachadeterministicformofEthernet.AsAFDXisoverEthernet,somespecificationsofAFDXaresimilartotheonesforregularEthernet.EDEisafeatureaddedtoAFDXtoenhancethecommunicationreliability.Thissection'sgoalistoclarifysomeofthemostimportantpointsofhowframesarebuilt.I-1.AFDXframelayoutAsshowninFigure1,theAFDXMessage(Payload)isencapsulatedin3mainotherlayers:-UDPlayer-IPlayer-MAClayer(headerandfooter)Figure1-Messageencapsulation476EE0CE47AEachlayerisreservedfordefinedfields.Onlymainfieldsaredetailedbelow.#UDP:8bytesUDPsourceport:PortusedbythesendingunitUDPdestinationport:Porttobeusedbythereceivingunit#IP:20bytesIPsource:IPaddressoftheunitsendingtheframeIPdestination:IPaddressoftheunitthathastoreceiveFragmentation:AnIPDatagramcanbefragmentedintomultiplepackets,forexample,whenthemessagesizeistoolongforonedatagram.Ifthemessageisfragmented,aflagisraisedintheIPlayer.Length:Sizeinbytesof[IP+UDP+Message]#MACHeader:14bytesMACsource:MACaddressofthesendingunitMACdestination:MACaddressoftheunitthathastoreceivetheframeVirtualLinkID:TheVirtualLink(VL)isakeycomponentofAFDX.AVLisacommunicationcanalbetweentwounits.AVLhasaspecifiedbandwidth,amaximumframesizeandminimumtimegapbetweentwoframes.ItisbecauseoftheVLspecificationsthattheAFDXisadeterministicEthernetprotocol.#MACFooter:5bytesMACFCS:FramechecksequenceMACSN:SequencenumberFigure2isanexampleofAFDXframe.Thebolddigitscorrespondtothefieldsdetailedabove.A7819DAD4253000C0020000026E5000252181100000100000001211DFigure2-FramelayoutLayerFieldExampleinhexExampleindecimal,whenrelevantPayloadUsefuldataBlueUDPSourcePortF3D362419UDPDestinationPortF3D362419IPSourceAddress0A.2A.29.2910.42.41.410300000090120200003A30290800450000341A17000001110B5B0A2A2929E0E08014F3D3F3D3MACheaderIP5PAYLOADEDEfooterPAYLOADEDEheaderMACfooterUDPLayerFieldExampleinhexExampleindecimal,whenrelevantIPDestinationAdressE0.E0.80.14224.224.128.20IPFragmentation0000IPLength003452bytesMACSource02:00:00:3A:30:29MACDestination03:00:00:00:90:12MACVLID(lasttwobytesofMACdestination)901236882MACFCS76EE0CE4MACSN7AI-2.EDEMessageformatTheErrorDetectionEncoding(EDE)hasbeenin...
