BS IS0 20794-3:2020 BSI Standards Publication Road vehicles Clock extension peripheral interface (CXPI) Part 3: Transport and networklayer bsi. BS ISO 20794-3:2020 BRITISH STANDARD Nationalforeword This British Standard is the UK implementation of IS020794-3:2020. The UK participation in its preparation was entrusted to Technical Committee AUE/16, Data Communication (Road Vehicles). A list of organizations represented on this committee can be obtained on requestto its secretary. This publication does not purport to include all the necessary provisions ofa contract.Users areresponsiblefor its correctapplication. @TheBritishStandards Institution2020 Published byBSIStandards Limited2020 ISBN9780580972256 ICS43.040.15 Compliance with a British Standard cannot confer immunity from legalobligations. This British Standard was published under the authority of the Standards Policyand StrategyCommittee on29February2020. Amendments/corrigenda issued sincepublication Date Text affected BS ISO 20794-3:2020 INTERNATIONAL ISO STANDARD 20794-3 First edition 2020-02 Road vehicles Clock extension peripheral interface (CXPI) - Part 3: Transport and network layer Vehicules routiers-Interface du peripherique d'extension d'horloge (CXPI) - Partie 3:Transport et couche réseau Reference number IS0 20794-3:2020(E) ISO @ISO2020 BSISO20794-3:2020 IS020794-3:2020(E) COPYRIGHTPROTECTEDDOCUMENT IS02020 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting below or Iso's member body in the country of the requester. ISO copyright office CP 401 : Ch. de Blandonnet 8 CH-1214 Vernier, Geneva Phone:+41227490111 Fax: +41 22 749 09 47 Email: [email protected] Website: www.iso.org Published in Switzerland ii @ISo 2020 -All rights reserved BSISO20794-3:2020 IS020794-3:2020(E) Contents Page Foreword ..V Introduction. ..i. 1 Scope. 2 Normative references 3 Terms and definitions 4 Symbolsand abbreviated terms ..2 .2 4.1 Symbols .2 4.2 Abbreviated terms 5 Conventions .3 6 Overviewoftransportlayerand networklayer .3 6.1 Properties.... .3 .3 6.2 Packet types 6.3 Errordetectionand indication. .3 Service interface parameters (SIP) 7 .3 .3 7.1 SIP-( General 7.2 SIPData type definitions 4 7.3 SIPTA, target address ..4 7.4 SIP-SA, source address. 4 7.5 SIPPtype,packettype ..4 7.6 SIPReqld, requestidentifier 4 7.7 SIPReqTypeld,requesttypeidentifier .5 7.8 SIP-PDU, protocol data unit .5 7.9 SIPLength, length of PDU. 5 7.10 SIP—NMInfo, network management information .5 7.11 SIP-ScT, sequence count. .5 SIPResult, result ..6 7.12 8 Transportlayer (TL) ..6 SI T_Data.req and T_Data.ind service interface 8.1 .6 8.2 SI T_Data.req and T_Data.ind service interface parameter mapping 7 8.3 TLService interfacewithT_Ptypeparametermapping 8 8.3.1 TL- T_Data.req and T_Data.ind with T_Ptype = NormalCom (T_Length = NULL)8 8.3.2 TL- T_Data.req and T_Data.ind with T_Ptype = NormalCom (T_Length ≥'o')... 9 8.3.3 TLT_Data.req and T_Data.ind interface with T_Ptype = DiagNodeCfg ..10 8.4 TL — Internal operation .11 8.5 TL - T_PDU .11 8.5.1 TL-TPDU definition. .11 8.5.2 TL-T_PCIdefinition .11 TLI 8.6 Function models. ..12 8.6.1 TLTransmission logic .12 8.6.2 TL—Receptionlogic 8.7 TL—Error detection .14 9 Network layer (NL) ..14 9.1 SI N_Data.req and N_Data.ind service interface 9.2 SI -N_Data.req and N_Data.ind service interface parametermapping. .15 9.3 NLServiceinterfacewithN_Ptypeparametermapping. .16 9.3.1 NL-N_Data.req and N_Data.ind with N_Ptype=NormalCom (N_Length NULL) .16 9.3.2 TL-N_Data.req and N_Data.ind with N_Ptype=NormalCom (N_Length ≥'o').17 9.3.3 NLN_Data.req and N_Data.ind interfacewith N_Ptype=DiagNodeCfg ..18 9.4 NLInternal operation .19 9.5 .19 NLN_PDU iii IS02020-Allrightsreserved BSIS020794-3:2020 IS0 20794-3:2020(E) 9.5.1 NL-N_PDU definition. 19 9.5.2 NL—N_NAD definition 19 9.