ISO 20794-2:2020

Road vehicles — Clock extension peripheral interface (CXPI) — Part 2: Application layer

This document describes the application layer protocol including the application measurement and control data management, message transfer and fault management. The application and application layer contain the following descriptions: — message structure; — communication method; — network management (optional); — measurement and control data; and — error handling. This document also specifies: — the service interface; and — the service interface parameters.

Véhicules routiers — Interface du périphérique d'extension d'horloge (CXPI) — Partie 2: Couche Application

General Information

• Status: Published
• Publication Date: 04-Feb-2020
• ICS: 43.040.15 - Car informatics. On board computer systems
• Technical Committee: ISO/TC 22/SC 31 - Data communication
• Drafting Committee: ISO/TC 22/SC 31/WG 3 - In-vehicle networks
• Current Stage: 9020 - International Standard under periodical review
• Start Date: 15-Jan-2025
• Due Date: 15-Jan-2025
• Completion Date: 15-Jan-2025

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 20794-2
First edition
2020-02
Road vehicles — Clock extension
peripheral interface (CXPI) —
Part 2:
Application layer
Véhicules routiers — Interface du périphérique d'extension d'horloge
(CXPI) —
Partie 2: Couche Application
Reference number
©
ISO 2020
© ISO 2020
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
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
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: [phone]
Fax: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms . 3
4.1 Symbols . 3
4.2 Abbreviated terms . 3
5 Conventions . 4
6 Introduction to application and application layer . 4
6.1 Application properties . 4
6.2 Application layer properties . 4
6.3 Message transmission . 4
6.4 Communication methods . 4
6.5 Message types . 5
6.6 Error handling . 5
7 Service interface parameters (SIP) . 5
7.1 SIP — General . 5
7.2 SIP — Data type definitions . 5
7.3 SIP — Mtype, message type . 6
7.4 SIP — ReqId, request identifier . 6
7.5 SIP — ReqTypeId, request type identifier . 6
7.6 SIP — PDU, protocol data unit . 6
7.7 SIP — Length, length of PDU . 6
7.8 SIP — ev_wakeup_ind, event wake-up indication (optional) . 6
7.9 SIP — cmd_wakeup_req, command wake-up request . 7
7.10 SIP — NMInfo, network management information . . 7
7.11 SIP — SCT, sequence count . 8
7.12 SIP — Result, result . 8
8 SI — Service interface (SI) definition to application and lower OSI layers .8
8.1 SI — A_Data.req and A_Data.ind service interface . 8
8.2 SI — A_Data.req and A_Data.ind service interface parameter mapping . 9
9 Application (APP) . 9
9.1 APP — Message exchange . 9
9.2 APP — Communication methods . 9
9.2.1 APP — General . 9
9.2.2 APP — Event-triggered method .10
9.2.3 APP — Polling method . .10
9.3 APP — Network management (NM) .11
9.3.1 APP — General .11
9.3.2 APP — Normal, standby, and sleep states .12
9.3.3 APP — Normal state .13
9.3.4 APP — Sleep state (optional) .14
9.3.5 APP — Standby state (optional) .14
9.3.6 APP — Wake-up/sleep function (optional) .14
9.3.7 APP — Wake-up/sleep sequence parameter .24
9.4 APP — Multi clock master sequence processing .24
9.5 APP — Measurement and/or control data .25
9.5.1 APP — Publisher and subscriber data .25
9.5.2 APP — Measurement and/or control data management .26
9.5.3 APP — Measurement and/or control data types.26
9.5.4 APP — Measurement and/or control data consistency .26
9.5.5 APP — Assignment of ReqId . .27
9.5.6 APP — Priority of ReqId .27
9.6 APP — Error handling .28
9.6.1 APP — General .28
9.6.2 APP — CXPI network error.28
9.6.3 APP — Network management information .29
9.6.4 APP — SCT, sequence count (optional) .30
9.6.5 APP — Sequence count (SCT) error (optional) .31
9.6.6 APP — Transmission prohibition . .31
9.6.7 APP — Retransmission . .32
9.6.8 APP — Error notification on CXPI network (optional).32
10 Application layer (AL) .33
10.1 AL — Message exchange .33
10.2 AL — Message structure .34
10.3 AL — Request protected type identifier field .35
10.4 AL — Request protected identifier field .35
10.4.1 AL — General .35
10.4.2 AL — Judgment of received message .35
10.5 AL — Response field (A_PDU) .35
10.5.1 AL — General .35
10.5.2 AL — A_PDU . .35
10.5.3 AL — Wake-up indication and request .36
10.6 AL — Error detection .36
Bibliography .37
iv © ISO 2020 – All rights reserved

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Eac
...

INTERNATIONAL ISO
STANDARD 20794-2
First edition
2020-02
Road vehicles — Clock extension
peripheral interface (CXPI) —
Part 2:
Application layer
Véhicules routiers — Interface du périphérique d'extension d'horloge
(CXPI) —
Partie 2: Couche Application
Reference number
©
ISO 2020
© ISO 2020
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
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
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: [phone]
Fax: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms . 3
4.1 Symbols . 3
4.2 Abbreviated terms . 3
5 Conventions . 4
6 Introduction to application and application layer . 4
6.1 Application properties . 4
6.2 Application layer properties . 4
6.3 Message transmission . 4
6.4 Communication methods . 4
6.5 Message types . 5
6.6 Error handling . 5
7 Service interface parameters (SIP) . 5
7.1 SIP — General . 5
7.2 SIP — Data type definitions . 5
7.3 SIP — Mtype, message type . 6
7.4 SIP — ReqId, request identifier . 6
7.5 SIP — ReqTypeId, request type identifier . 6
7.6 SIP — PDU, protocol data unit . 6
7.7 SIP — Length, length of PDU . 6
7.8 SIP — ev_wakeup_ind, event wake-up indication (optional) . 6
7.9 SIP — cmd_wakeup_req, command wake-up request . 7
7.10 SIP — NMInfo, network management information . . 7
7.11 SIP — SCT, sequence count . 8
7.12 SIP — Result, result . 8
8 SI — Service interface (SI) definition to application and lower OSI layers .8
8.1 SI — A_Data.req and A_Data.ind service interface . 8
8.2 SI — A_Data.req and A_Data.ind service interface parameter mapping . 9
9 Application (APP) . 9
9.1 APP — Message exchange . 9
9.2 APP — Communication methods . 9
9.2.1 APP — General . 9
9.2.2 APP — Event-triggered method .10
9.2.3 APP — Polling method . .10
9.3 APP — Network management (NM) .11
9.3.1 APP — General .11
9.3.2 APP — Normal, standby, and sleep states .12
9.3.3 APP — Normal state .13
9.3.4 APP — Sleep state (optional) .14
9.3.5 APP — Standby state (optional) .14
9.3.6 APP — Wake-up/sleep function (optional) .14
9.3.7 APP — Wake-up/sleep sequence parameter .24
9.4 APP — Multi clock master sequence processing .24
9.5 APP — Measurement and/or control data .25
9.5.1 APP — Publisher and subscriber data .25
9.5.2 APP — Measurement and/or control data management .26
9.5.3 APP — Measurement and/or control data types.26
9.5.4 APP — Measurement and/or control data consistency .26
9.5.5 APP — Assignment of ReqId . .27
9.5.6 APP — Priority of ReqId .27
9.6 APP — Error handling .28
9.6.1 APP — General .28
9.6.2 APP — CXPI network error.28
9.6.3 APP — Network management information .29
9.6.4 APP — SCT, sequence count (optional) .30
9.6.5 APP — Sequence count (SCT) error (optional) .31
9.6.6 APP — Transmission prohibition . .31
9.6.7 APP — Retransmission . .32
9.6.8 APP — Error notification on CXPI network (optional).32
10 Application layer (AL) .33
10.1 AL — Message exchange .33
10.2 AL — Message structure .34
10.3 AL — Request protected type identifier field .35
10.4 AL — Request protected identifier field .35
10.4.1 AL — General .35
10.4.2 AL — Judgment of received message .35
10.5 AL — Response field (A_PDU) .35
10.5.1 AL — General .35
10.5.2 AL — A_PDU . .35
10.5.3 AL — Wake-up indication and request .36
10.6 AL — Error detection .36
Bibliography .37
iv © ISO 2020 – All rights reserved

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Eac
...