ISO 17987-4:2016

DRAFT INTERNATIONAL STANDARD
ISO/DIS 17987-4.2
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 4:
Electrical Physical Layer (EPL) specification 12V/24V
Véhicules routiers — Réseau Internet local (LIN) —
Partie 4: Spécification de la couche électrique physique (EPL) 12V/24V
ICS: 43.040.15
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ISO/DIS 17987-4.2:2015(E)
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PROVIDE SUPPORTING DOCUMENTATION. ISO 2015

ISO/DIS 17987-4.2:2015(E)
© ISO 2015, Published in Switzerland
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ii © ISO 2015 – All rights reserved

ISO/DIS 17987-4.2
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 . 2
3.3 Abbreviated terms . 5
4 Conventions . 6
5 Electrical physical layer requirements . 6
5.1 Bit rate deviation . 6
5.2 Timing requirements . 9
5.3 Line driver/receiver . 11
Annex A (informative) LIN peripheral interface design considerations . 22
A.1 General . 22
A.2 UART requirements . 22
A.3 LIN frame controller requirements . 24
Bibliography . 27

ISO/DIS 17987-4.2
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 17987-4 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/DIS 17987-4.2
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 transportation.
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;
 Bitrate 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 state in a controlled manner;
 Status management that provides error handling and error signalling;
 Transport layer that allows large amount of data to be transported (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/DIS 17987-4.2
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

DRAFT INTERNATIONAL STANDARD ISO/DIS 17987-4.2

1 Road vehicles — Local Interconnect Network (LIN) — Part 4:
2 Electrical Physical Layer (EPL) specification 12V/24V
3 1 Scope
4 This part of ISO 17987 specifies the 12 V and 24 V electrical physical layers (EPL) of the LIN communications
5 system.
6 The electrical physical layer for LIN is designed for low cost networks with bit rates up to 20 kbit/s to connect
7 automotive electronic control units (ECUs). The medium that is used is a single wire for each, receiver and
8 transmitter with reference to ground.
9 This part of ISO 17987 includes the definition of electrical characteristics of the transmission itself and also
10 documentation of basic functionality for bus driver devices.
11 All parameters in this specification are defined for the ambient temperature range from -40°C to 125°C.
12 2 Normative references
13 The following referenced documents are indispensable for the application of this document. For dated
14 references, only the edition cited applies. For undated references, the latest edition of the referenced
15 document (including any amendments) applies.
16 ISO 17987 (Part 2, 3, 6 and 7), Road vehicles – Local interconnect network (LIN)
17 3 Terms, definitions, symbols and abbreviated terms
18 3.1 Terms and definitions
19 For the purposes of this document, the following terms and definitions apply.
20 3.1.1
21 BR_Range_20K
22 LIN systems which operate at speeds up to 20 kbit/s
23 3.1.2
24 BR_Range_20K 12 V
25 12 V LIN systems which operate at speeds up to 20 kbit/s
26 3.1.3
27 BR_Range_20K 24 V
28 24 V LIN systems which operate at speeds up to 20 kbit/s
29 3.1.4
30 BR_Range_10K
31 LIN systems which operate at speeds up to 10,417 kbits/s
ISO/DIS 17987-4.2
32 3.1.5
33 BR_Range_10K 12 V
34 12 V LIN systems which operate at speeds up to 10,417 kbits/s
35 3.1.6
36 BR_Range_10K 24 V
37 24 V LIN systems which operate at speeds up to 10,417 kbit/s
38 3.2 Symbols
% percentage
µs microsecond
C' line capacitance
LINE
C total bus capacitance
BUS
C capacitance of master node
MASTER
C RXD capacitance (LIN receiver, RXD capacitive load condition)
RXD
C capacitance of slave node
SLAVE
d²V/dt² second derivative of voltage (Volt² per second²)
di/dt instantaneous rate of current change (amps per second)
D serial internal diode at transceiver IC
ser_int
D serial master diode
ser_master
F master bit rate deviation from nominal bitrate
TOL_RES_MASTER
F master bit rate deviation from nominal bitrate in BR_Range_20K systems
TOL_RES_MASTER_A
F master bit rate deviation from nominal bitrate in BR_Range_10K systems
TOL_RES_MASTER_B
F slave bit rate deviation from nominal bitrate
TOL_RES_SLAVE
F slave bit rate deviation from nominal bitrate in BR_Range_20K systems
TOL_RES_SLAVE_A
F slave bit rate deviation from nominal bitrate in BR_Range_10K systems
TOL_RES_SLAVE_B
F slave node 1 bit rate deviation from nominal bitrate
TOL_RES_SLAVE_1
F slave node 2 bit rate deviation from nominal bitrate
TOL_RES_SLAVE_2
F slave to slave bit rate deviation
TOL_SLAVE_to_SLAVE
F slave node bit rate deviation from master node bit rate after synchronization
TOL_SYNCH
F slave node bit rate deviation from master node bit rate after synchronization in
TOL_SYNCH_A
BR_Range_20K systems
F slave node bit rate deviation from master node bit rate after synchronization in
TOL_SYNCH_B
BR_Range_10K systems
2 © ISO 2015 – All rights reserved

ISO/DIS 17987-4.2
F slave node 1 bit rate deviation from master node bit rate after synchronization
TOL_SYNCH_1
F slave node 2 bi
...