ISO 11519-2:1994/Amd 1:1995

INTERNATIONAL
ISO
STANDARD
11519-2
First edition
1994-06-15
AMENDMENT 1
1995-0441
Woad vehicles
- Low-Speed serial data
communication -
Part 2:
Low-Speed controller area network (CAN)
AMENDMENT 1
Whicules routiers - Communication en Serie de donnees 2
vitesse basse -
Partie 2: Gestionnaire de rkseau de communication a faible vitesse (CAN)
AMETVDEMENT 7
Reference number
ISO 11519-2: 1994/Amd. 1 :1995(E)

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ISO 11519-2:1994/Amd.l:1995(E)
IForeword
iS0 (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. Esch member body interested in a subject for which
a technical committee has been established has the 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.
Draft International Standards adopted by the technical committees are
circulated to the member bodies for voting. Publication as an International
Standard requires approval by at least 75 % of the member bodies casting
a vote.
Amendment 1 to International Standard ISO 11519-2:1994 was prepared
by Technical Committee lSO/TC 22, Road vehicles, Subcommittee SC 3,
Electrical and electronie equipment.
ISO 11519 consists of the following Parts, under the general title ßoad
vehicles - Low-Speed serial data communication :
- Part 1: General and definitions
- Part 2: Low-Speed controller area network (CAN)
- Part 3: Vehicle area network (VAN)
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced
or utilized in any form or by any means, electronrc or mechanrcal, rncluding photocopying and
nxrofilm, without permission In writing from the publisher.
International Organization for Standardization
Gase postale 56 l CH-1 211 Geneve 20 l Switzerland
Printed in Switzerland
ii

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0 ISO ISO 11519-2:1994/Amd.l:1995(E)
Road vehides - Low-Speed serial data communication -
Part 2:
Low-Speed controller area network (CAN)
AMENDMENT 1
Page iv
Insert new page v and the following Introduction.
Introduction
The acceptance and introduction of serial data communication to more and more applications has led to
requirements that the assignment of message identifiers to communication functions be standardized for
certain applications. These applications tan be realized with CAN more comfortably, if the address range that
has been defined in ISO 11519-1 by 11 identifier bits is enlarged.
Therefore a second message format ( “extended format ”) is introduced that provides a larger address range
defined by 29 bits. This will relieve the System designer from compromises with respect to defining wel!-
structured naming schemes. Users of CAN who do not need the identifier range offered by the extended
format tan rely on the conventional 11 bit identifier range ( “Standard format ”) further on.
In Order to distinguish Standard and extended format the first reserved bit of the CAN message format, as it is
defined in ISO 11519-1, is used. This is done in such a way that the message format in ISO 11519-1 is
equivalent to the Standard format and therefore is still valid. Furthermore, the extended format has been
defined so that messages in Standard format and extended format tan coexist within the Same network.
Amendment 1 to ISO 11519-2 details the necessary changes to the 1994 Standard to include both formats.
Page IO
Replace the wording below item b.2 of 6.1 (Service of the LLC sublayer) by the following.
According to the two different LLC Services there are two types of frames from or to the User:
- LLC Data Frame,
- LLC Remote Frame.
There are two formats for both Data Frames and Remote Frames which differ in the length of the identifier
6.2): Fr ames with an 11 bit IDENTIFIER are denoted STANDARD LLC Frames, and Frames containing a 29
(see
bit IDENTIFIER are denoted Extended LLC Frames.

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ISO 11519-2:1994/Amd.l:1995(E) 0 ISO
In 6.2, replace table 3 by
the following.
Table 3 - List of LLC Service primitive Parameters
idendifies the data and its priority
I I
Data Length Code
DLC
DATA data the user wants to transmit
TRANSFER-STATUS confirmation Parameter
I I I
Replace item b) of 6.2.1 L-DATA.request, by the following.
b) Semantics of the L DATA.request primitive
-
The primitive shall provide Parameters as follows.
L-DATA.request(
IDE
IDENTIFIER
DLC
DATA
>
The Parameter DATA is insignificant if the associated LLC Data Frame is of data length Zero.
Replace item b) of 6.2.2 L-DATA.indication, by the following.
b) Semantics of the L DATA.indication primitive
-
The primitive shall provide Parameters as follows.
L-DATA.indication (
IDE
IDENTIFIER
DLC
DATA
>
The Parameter DATA is insignificant if the associated LLC data frame is of data length Zero.
Page 72
Replace item b) of 6.2.3 L-DATA.confirm, by the following.
b) Semantics of the L-DATA.confirm primitive
The primitive shall provide Parameters as follows.
L-DATA.confirm(
IDE
IDENTIFIER
TRANSFER-STATUS
>

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0 ISO ISO 11519-2:1994/Amd.l:1995(E)
The TRANSFER-STATUS is used to indicate the completion of the transaction initiated by the previous
L DATA.request primitive.
-
TRANSFER STATUS:[COMPLETE,NOT COMPLETE]
- -
Replace item b) of 6.2.4 L-REMOTE.request, by the following.
b) Semantics of the L REMOTE.request primitive
-
The primitive shall provide Parameters as follows.
L-REMOTE.request(
IDE
IDENTIFIER
DLC
The value of DLC equals the length of the data field of the requested data frame.
Page 73
Replace item a) of 6.2.5 L-REMOTE.indication, by the following.
a) Function
The L REMOTE.indication primitive is passed from the LLC sublayer to the LLC user to indicate the arrival of a
requeit for transmission of a LSDU.
Replace item b) of 6.2.5 L-REMOTE.indication, by the following.
b) Semantics of the L REMOTE.indication primitive
-
The primitive shall provide Parameters as follows.
L-REMOTE.indication (
IDE
IDENTIFIER
DLC
The IDENTIFIER identifies the LSDU to be sent. The value of DLC equals the length of the data field of the
requested data frame.
Replace item b) of 6.2.6 L-REMOTE.confirm, by the following.
b) Semantics of the L REMOTE.confirm primitive
-
The primitive shall provide Parameters as follows.
L-REMOTE.confirm (
IDE
IDENTIFIER
TRANSFER-STATUS
)
The TRANSFER STATUS is used to indicate the completion of the transaction initiated by the previous
L REMOTE.requkt primitive.
-
TRANSFER STATUS:[COMPLETE,NOT COMPLETE]
- -
Replace 6.3 Structure of LLC frames, by the following.
LLC frames are the protocol data units that are exchanged between peer LLC entities (LPDUs). The structure
and format of the LLC Data and Remote Frame are specified subsequentiy.
3

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ISO 11519-2:1994/Amd.l:1995(E)
0 ISO
Page 14
Replace 6.3.1 Specification of the LLC data frame, by the following.
A LLC data frame is composed of four bit fields (see figure 4):
- IDE bit,
- Identifier Field,
- Data Length Code (DLC) Field,
- LLC Data Field.
IDE bit
Standard LLC Data Frames and Extended LLC Data Frames are distinguished by the IDE bit: IDE = ‘0’ indicates
the Standard Frame Format, and IDE = ‘1’ indicates the Extended Frame Format.
/den tifier Fjeld
Depending on the IDE bit, the identifier is either 11 bit long (Standard Frame Format), or 29 bit long (Extended
Frame Format). In case of the Standard Frame Format the 7 most significant bits (ID-IO to ID-4) must not be
all ‘1 ‘.
DLC field
The number of bytes in the data field is indicated by the Data Length Code. This Data Length Code consists of
4 bits. The data field tan be of length Zero. The admissible number of data bytes for a data frame ranges from
8. Other values may not be used.
0, . . . .
Replace figure 4 by the following.
. ,
I
Identifier DLC LLC Data
D
Field
Field Field
E
Figure 4 - LLC Data Frame
Page 75
Replace 6.3.2 Specification of the LLC Remote Frame, by the following.
A LLC remote frame is composed of three bit fields:
- IDE bit,
- Identifier field,
- DLC field,
The structures of the bit fields IDE, Identifier Field, and DLC Field are equivalent to the structures of the
corresponding bit fields of a LLC Data Frame (see 6.2.1). The only differente between a LLC Remote Frame
and a LLC Data Frame is that there is no Data Field in a Remote Frame, independent of the value of the Data
Length Code. This value is the Data Length Code of the corresponding Data Frame.
Replace figure 5 by the following.
Figure 5 - LLC remote frame

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0 ISO ISO 11519-2:1994/Amd.l:1995(E)
Page 16
Add at the end of 8.1 Services of the MAC sublayer, the following new wording.
According to the two different MAC data transfer Services there are two types of frames from or to the User:
- MAC Data Frame,
- MAC Remote Frame.
There are two different formats for both Data Frames and Remote Frames which differ in the length of the
IDENTIFIER:
Frames with an 11 bit IDENTIFIER are denoted Standard MAC Frames, and
Frames containing 29 bit IDENTIFIER are denoted Extended MAC Frames.
Page 17
Amend items b) and c) of 8.1 .l .1 MA DATA.request, to read as follows.
-
DATA.request primitive
b) Semantics of the MA
-
The primitive shall provide Pa
...