ISO 17987-3:2016

DRAFT INTERNATIONAL STANDARD
ISO/DIS 17987-3.2
ISO/TC 22/SC 31 Secretariat: DIN
Voting begins on: Voting terminates on:
2015-10-05 2015-12-05
Road vehicles — Local Interconnect Network (LIN) —
Part 3:
Protocol specification
Véhicules routiers — Réseau Internet local (LIN) —
Partie 3: Spécification du protocole
ICS: 01.040.43; 43.020
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ISO/DIS 17987-3.2:2015(E)
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ISO/DIS 17987-3.2:2015(E)
© ISO 2015, Published in Switzerland
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ii © ISO 2015 – All rights reserved

ISO/FDIS 17987-3:2015(E)
Contents Page
Foreword . iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms, definitions, symbols and abbreviated terms . 1
3.1 Terms and definitions . 1
3.2 Symbols . 4
3.3 Abbreviated terms . 4
4 Node concept . 5
4.1 Concept of operation . 5
5 Protocol requirements . 7
5.1 Signal . 7
5.2 Frame . 9
5.3 Schedule tables . 20
5.4 Task behaviour model . 21
5.5 Status management . 24
6 Node configuration and identification . 25
6.1 General . 25
6.2 LIN product identification . 26
6.3 Slave node model . 27
Annex A (normative) Definition of properties, frame identifiers and various examples . 36
A.1 Definition of numerical properties . 36
A.2 Definition of valid frame identifiers . 36
A.3 Example of checksum calculation . 38
A.4 Example of sequence diagrams . 39
Annex B (informative) LIN history and version compatibility . 40
B.1 LIN history and background . 40
B.2 LIN version compatibility . 40
B.3 Changes between LIN versions . 41
Annex C (informative) LIN auto addressing methods . 44
C.1 Auto addressing method and method IDs . 44
C.2 Auto addressing method ID. 44
Bibliography . 46

ISO/FDIS 17987-3:2015(E)
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. Each 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.
International 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 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.
ISO 17987-3 was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 31,
Electrical and electronic equipment.
ISO 17987 consists of the following parts, under the general title Road vehicles — Local Interconnect Network
(LIN):
 Part 1: General information and use case definition
 Part 2: Transport protocol and network layer services
 Part 3: Protocol specification
 Part 4: Electrical Physical Layer (EPL) specification (12 V / 24 V)
 Part 5: Application Programmers Interface (API)
 Part 6: Protocol conformance test specification
 Part 7: Electrical Physical Layer (EPL) conformance test specification
iv © ISO 2015 – All rights reserved

ISO/FDIS 17987-3:2015(E)
Introduction
This document set specifies the use cases, the communication protocol and physical layer requirements of an
in-vehicle communication network called "Local Interconnect Network (LIN)".
The LIN protocol as proposed is an automotive focused low speed UART-based network (Universal
Asynchronous Receiver Transmitter). Some of the key characteristics of the LIN protocol are signal based
communication, schedule table based frame transfer, master/slave communication with error detection, node
configuration and diagnostic service communication.
The LIN protocol is for low cost automotive control applications, for example door module and air condition
systems. It serves as a communication infrastructure for low-speed control applications in vehicles by
providing:
 Signal based communication to exchange information between applications in different nodes;
 Bit rate support from 1 kbit/s to 20 kbit/s;
 Deterministic schedule table based frame communication;
 Network management that wakes up and puts the LIN cluster into sleep mode in a controlled manner;
 Status management that provides error handling and error signalling;
 Transport layer that allows large amount of data to be transmitted (such as diagnostic services);
 Specification of how to handle diagnostic services;
 Electrical physical layer specifications;
 Node description language describing properties of slave nodes;
 Network description file describing behaviour of communication;
 Application programmer's interface;

ISO 17987 is based on the Open Systems Interconnection (OSI) Basic Reference Model as specified in
ISO/IEC 7498-1 which structures communication systems into seven layers.
The OSI model structures data communication into seven layers called (top down) application layer (layer 7),
presentation layer, session layer, transport layer, network layer, data link layer and physical layer (layer 1). A
subset of these layers is used in ISO 17987.
ISO 17987 distinguishes between the services provided by a layer to the layer above it and the protocol used
by the layer to send a message between the peer entities of that layer. The reason for this distinction is to
make the services, especially the application layer services and the transport layer services, reusable also for
other types of networks than LIN. In this way the protocol is hidden from the service user and it is possible to
change the protocol if special system requirements demand it.

ISO/FDIS 17987-3:2015(E)
This document set provides all documents and references required to support the implementation of the
requirements related to.
 Part 1: General information and use case definitions
This part provides an overview of the document set and structure along with the use case definitions and
a common set of resources (definitions, references) for use by all subsequent parts.
 Part 2:
This part specifies the requirements related to the transport protocol and the network layer requirements
to transport the PDU of a message between LIN nodes.
 Part 3:
This part specifies the requirements for implementations of the LIN protocol on the logical level of
abstraction. Hardware related properties are hidden in the defined constraints.
 Part 4:
This part specifies the requirements for implementations of active hardware components which are
necessary to interconnect the protocol implementation.
 Part 5 (published as a non-normative technical report):
This part specifies the LIN API (Application Programmers Interface) and the node configuration and
identification services. The node configuration and identification services are specified in the API and
define how a slave node is configured and how a slave node uses the identification service.
 Part 6:
This part specifies tests to check the conformance of the LIN protocol implementation according to
ISO 17987-2 and ISO 17987-3. This comprises tests for the data link layer, the network layer and the
transport layer.
 Part 7:
This part specifies tests to check the conformance of the LIN electrical physical layer implementation
(logical level of abstraction) according to ISO 17987-4.

vi © ISO 2015 – All rights reserved

FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 17987-3:2015(E)

1 Road vehicles — Local Interconnect Network (LIN) — Part 3:
2 Protocol specification
3 1 Scope
4 This part of ISO 17987 specifies the LIN protocol including the signal management, frame transfer, schedule
5 table handling, task behaviour and status management and LIN master and slave node. It contains also OSI
6 layer 5 properties according to ISO 14229-7 UDSonLIN based node configuration and identification services
7 (SID: B0 to B8 ) belonging to the core protocol specification.
16 16
8 A node (normally a master node) that is connected to more than one LIN network is handled by higher layers
9 (e.g. the application) not in the scope of this document.
10 2 Normative references
11 The following referenced documents are indispensable for the application of this document. For dated
12 references, only the edition cited applies. For undated references, the latest edition of the referenced
13 document (including any amendments) applies.
14 ISO 17987 (Part 2, 4, 6 and 7), Road vehicles – Local Interconnect Network (LIN)
15 3 Terms, definitions, symbols and abbreviated terms
16 3.1 Terms and definitions
17 For the purposes of this document, the following terms and definitions and those given in ISO 17987-1:2015
18 apply.
19 3.1.1
20 big-endian
21 method of storage of multi-byte numbers with the most significant bytes at the lowest memory addresses
22 broadcast NAD
23 a broadcast NAD is addressing every slave node on LIN
24 3.1.2
25 bus interface
26 the hardware (transceiver, UAR
...