1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 17458-2:2013Road vehicles FlexRaycommunications systemPart 2: Data link layer specificationBS ISO 17458-2:2013 BRITISH STANDARDNational forewordThis British Standard is th
2、e UK implementation of ISO 17458-2:2013.The UK participation in its preparation was entrusted to TechnicalCommittee AUE/16, Electrical and electronic equipment.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to includ
3、e all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2013. Published by BSI StandardsLimited 2013ISBN 978 0 580 76713 5ICS 43.040.15Compliance with a British Standard cannot confer immunity fromlegal obligations.This British
4、 Standard was published under the authority of theStandards Policy and Strategy Committee on 31 January 2013.Amendments issued since publicationDate Text affectedBS ISO 17458-2:2013Reference numberISO 17458-2:2013(E)ISO 2013INTERNATIONAL STANDARD ISO17458-2First edition2013-02-01Road vehicles FlexRa
5、y communications system Part 2: Data link layer specification Vhicules routiers Systme de communications FlexRay Partie 2: Spcification de la couche de liaison de donnes BS ISO 17458-2:2013ISO 17458-2:2013(E) COPYRIGHT PROTECTED DOCUMENT ISO 2013 All rights reserved. Unless otherwise specified, no p
6、art of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale
7、 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2013 All rights reservedBS ISO 17458-2:2013ISO 17458-2:2013(E) ISO 2013 All rights reserved iii Contents Page Foreword . v Introduction vi 1 Scope 1 2 Normative
8、references 1 3 Terms, definitions, symbols and abbreviated terms . 1 3.1 Terms and definitions . 1 3.2 Symbols 7 3.3 Abbreviated terms . 7 4 Document overview . 10 5 Conventions . 11 5.1 General . 11 5.2 Notational conventions . 11 5.3 SDL conventions . 12 5.4 Bit rates 15 5.5 Roles of a node in a F
9、lexRay cluster . 15 5.6 Synchronisation methods 15 5.7 Network topology considerations . 19 5.8 Example node architecture. 24 6 Protocol operation control . 29 6.1 Principles 29 6.2 Description . 31 6.3 The protocol operation control process . 37 7 Coding and Decoding . 59 7.1 Principles 59 7.2 Desc
10、ription . 59 7.3 Coding and decoding process . 77 7.4 Bit strobing process 96 7.5 Wakeup pattern decoding process 99 8 Frame Format . 103 8.1 Overview . 103 8.2 FlexRay header segment (5 bytes) 103 8.3 FlexRay payload segment (0 254 bytes) 108 8.4 FlexRay trailer segment 111 8.5 CRC calculation deta
11、ils . 111 9 Media Access Control . 113 9.1 Principles 113 9.2 Description . 123 9.3 Media access control process . 126 10 Frame and Symbol processing 143 10.1 Principles 143 10.2 Description . 143 10.3 Frame and symbol processing process 149 11 Wakeup and Startup 161 11.1 General . 161 11.2 Cluster
12、wakeup 162 11.3 Communication startup and reintegration 167 BS ISO 17458-2:2013ISO 17458-2:2013(E) iv ISO 2013 All rights reserved 12 Clock synchronisation 190 12.1 Introduction 190 12.2 Time representation 191 12.3 Synchronisation process 193 12.4 Startup of the clock synchronisation 200 12.5 Time
13、measurement 204 12.6 Correction term calculation 208 12.7 Clock correction. 220 12.8 Sync frame configuration . 223 12.9 Time gateway interface . 225 13 Controller Host Interface . 226 13.1 Principles 226 13.2 Description . 227 13.3 Interfaces 228 Annex A (normative) System parameters . 268 A.1 Prot
14、ocol constants 268 A.2 Performance constants . 270 Annex B (normative) Configuration constraints 271 B.1 General 271 B.2 Bit rates . 271 B.3 Parameters . 272 B.4 Calculation of configuration parameters for nodes in a TT-D cluster 281 B.5 Configuration of cluster synchronisation method and node synch
15、ronisation role . 334 B.6 Calculation of configuration parameters for nodes in a TT-L cluster 335 B.7 Calculation of configuration parameters for nodes in a TT-E cluster 336 Annex C (normative) Wakeup application notes . 345 C.1 Scope 345 C.2 Wakeup initiation by the host . 345 C.3 Host reactions to
16、 status flags signalled by the communication controller. 348 C.4 Retransmission of wakeup patterns 349 C.5 Transition to startup 349 C.6 Wakeup during operation . 350 Bibliography 352 BS ISO 17458-2:2013ISO 17458-2:2013(E) ISO 2013 All rights reserved v Foreword ISO (the International Organization f
17、or 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. Each member body interested in a subject for which a technical committee has been established has th
18、e right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Internat
19、ional Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication
20、 as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
21、 ISO 17458-2 was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 3, Electrical and electronic equipment. ISO 17458 consists of the following parts, under the general title Road vehicles FlexRay communications system: Part 1: General information and use case definition Part
22、2: Data link layer specification Part 3: Data link layer conformance test specification Part 4: Electrical physical layer specification Part 5: Electrical physical layer conformance test specification BS ISO 17458-2:2013ISO 17458-2:2013(E) vi ISO 2013 All rights reserved Introduction The FlexRay com
23、munications system is an automotive focused high speed network and was developed with several main objectives which were defined beyond the capabilities of established standardized bus systems like CAN and some other proprietary bus systems. Some of the basic characteristics of the FlexRay protocol
24、are synchronous and asynchronous frame transfer, guaranteed frame latency and jitter during synchronous transfer, prioritization of frames during asynchronous transfer, single or multi-master clock synchronisation, time synchronisation across multiple networks, error detection and signalling, and sc
25、alable fault tolerance. The FlexRay communications system is defined for advanced automotive control applications. It serves as a communication infrastructure for future generation high-speed control applications in vehicles by providing: A message exchange service that provides deterministic cycle
26、based message transport; Synchronisation service that provides a common time base to all nodes; Start-up service that provides an autonomous start-up procedure; Error management service that provides error handling and error signalling; Wakeup service that addresses the power management needs; Since
27、 start of development the automotive industry world wide supported the specification development. The FlexRay communications system has been successfully implemented in production vehicles today. The ISO 17458 series specifies the use cases, the communication protocol and physical layer requirements
28、 of an in-vehicle communication network called “FlexRay communications system“. This part of ISO 17458 has been established in order to define the protocol requirements for vehicle communication systems implemented on a FlexRay data link. To achieve this, it is based on the Open Systems Interconnect
29、ion (OSI) Basic Reference Model specified in ISO/IEC 7498-1 and ISO/IEC 10731, which structures communication systems into seven layers. When mapped on this model, the protocol and physical layer requirements specified by ISO 17458 are broken into: Diagnostic services (layer 7), specified in ISO 142
30、29-1 7, ISO 14229-4 9; Presentation layer (layer 6), vehicle manufacturer specific; Session layer services (layer 5), specified in ISO14229-2 8; Transport layer services (layer 4), specified in ISO 10681-2 5; Network layer services (layer 3), specified in ISO 10681-2 5; Data link layer (layer 2), sp
31、ecified in ISO 17458-2, ISO 17458-3; Physical layer (layer 1), specified in ISO 17458-4, ISO 17458-5; in accordance with Table 1. BS ISO 17458-2:2013ISO 17458-2:2013(E) ISO 2013 All rights reserved vii Table 1 FlexRay communications system specifications applicable to the OSI layers Applicability OS
32、I 7 layers FlexRay communications system Vehicle manufacturer enhanced diagnostics Seven layer according to ISO 7498-1 and ISO/IEC 10731 Application (layer 7) vehicle manufacturer specific ISO 14229-1, ISO 14229-4 Presentation (layer 6) vehicle manufacturer specific vehicle manufacturer specific Ses
33、sion (layer 5) vehicle manufacturer specific ISO 14229-2 Transport (layer 4) vehicle manufacturer specific ISO 10681-2 Network (layer 3) vehicle manufacturer specific Data link (layer 2) ISO 17458-2, ISO 17458-3 Physical (layer 1) ISO 17458-4, ISO 17458-5 Table 1 shows ISO 17458 Parts 2 5 being the
34、common standards for the OSI layers 1 and 2 for the FlexRay communications system and the vehicle manufacturer enhanced diagnostics. The FlexRay communications system column shows vehicle manufacturer specific definitions for OSI layers 3 7. The vehicle manufacturer enhanced diagnostics column shows
35、 application layer services covered by ISO 14229-4 which have been defined in compliance with diagnostic services established in ISO 14229-1, but are not limited to use only with them. ISO 14229-4 is also compatible with most diagnostic services defined in national standards or vehicle manufacturers
36、 specifications. The presentation layer is defined vehicle manufacturer specific. The session layer services are covered by ISO 14229-2. The transport protocol and network layer services are specified in ISO 10681. BS ISO 17458-2:2013BS ISO 17458-2:2013INTERNATIONAL STANDARD ISO 17458-2:2013(E) ISO
37、2013 All rights reserved 1 Road vehicles FlexRay communications system Part 2: Data link layer specification 1 Scope This part of ISO 17458 specifies the FlexRay communication protocol which is specified for a dependable automotive network. Some of the basic characteristics of the FlexRay protocol a
38、re synchronous and asynchronous frame transfer, guaranteed frame latency and jitter during synchronous transfer, prioritization of frames during asynchronous transfer, single or multi-master clock synchronisation1)time synchronisation across multiple networks, error detection and signalling, and sca
39、lable fault tolerance2). 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. I
40、SO 17458-1, Road vehicles FlexRay communications system Part 1: General information and use case definition 3 Terms, definitions, symbols and abbreviated terms 3.1 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 17458-1 and the following apply. 3.1.1 a
41、pplication data data produced and / or used by application tasks NOTE In the automotive context the term signal is often used for application data exchanged among tasks. 3.1.2 bus communication system topology in which nodes are directly connected to a single, common communication media (as opposed
42、to connection through stars, gateways, etc.) NOTE The term bus is also used to refer to the media itself. 1) Multi-master clock synchronisation refers to a synchronisation that is based on the clocks of several (three or more) synchronisation masters or sync nodes. 2) Scalable fault tolerance refers
43、 to the ability of the FlexRay protocol to operate in configurations that provide various degrees of fault tolerance (i.e., single or dual channel clusters, clusters with many or few sync nodes, etc.).BS ISO 17458-2:2013ISO 17458-2:2013(E) 2 ISO 2013 All rights reserved 3.1.3 channel idle condition
44、on the physical transmission medium when no node is transmitting, as perceived by each individual node in the network NOTE The detection of channel idle occurs some time after all nodes have actually stopped transmitting (due to idle detection times, channel effects, ringing, etc.). 3.1.4 clique set
45、 of communication controllers having the same view of certain systems properties EXAMPLE The global time value or the activity state of communication controllers. 3.1.5 cluster communication system of multiple nodes connected via at least one communication channel directly (bus topology), by active
46、stars (star topology) or by a combination of bus and star connections (hybrid topologies) NOTE Clusters can be coupled by gateways. 3.1.6 coldstart node node capable of initiating the communication startup procedure on the cluster by sending startup frames NOTE TT-D coldstart nodes, TT-L coldstart n
47、odes, and TT-E coldstart nodes are all considered to be coldstart nodes. By definition, all coldstart nodes are also sync nodes. 3.1.7 communication slot interval of time during which access to a communication channel is granted exclusively to a specific node for the transmission of a frame with a f
48、rame ID corresponding to the slot NOTE FlexRay distinguishes between static communication slots and dynamic communication slots. 3.1.8 cycle-dependent slot assignment method of assigning, for a given channel, an individual slot (identified by a specific slot number and a specific cycle counter numbe
49、r) or a set of slots (identified by a specific slot number and a set of communication cycle numbers) to a node 3.1.9 cycle-independent slot assignment method of assigning, for a given channel, the set of all communication slots having a specific slot number to a node (i.e., on the given channel, slots with the specific slot number are assigned to the node in all communication cycles) 3.1.10 cycle number positive integer used to identify a communication cycle NOTE The cycle n
