Road vehicles -- Local Interconnect Network (LIN)

ISO 17987-4:2016 specifies the 12 V and 24 V electrical physical layers (EPL) of the LIN communications system. The electrical physical layer for LIN is designed for low-cost networks with bit rates up to 20 kbit/s to connect automotive electronic control units (ECUs). The medium that is used is a single wire for each receiver and transmitter with reference to ground. ISO 17987-4:2016 includes the definition of electrical characteristics of the transmission itself and also the documentation of basic functionality for bus driver devices. All parameters in this document are defined for the ambient temperature range from −40 °C to 125 °C.

Véhicules routiers -- Réseau Internet local (LIN)

General Information

Status
Published
Publication Date
24-Aug-2016
Current Stage
9020 - International Standard under periodical review
Start Date
15-Jul-2021
Ref Project

Buy Standard

Standard
ISO 17987-4:2016 - Road vehicles -- Local Interconnect Network (LIN)
English language
27 pages
sale 15% off
Preview
sale 15% off
Preview
Standard
ISO 17987-4:2016 - Road vehicles -- Local Interconnect Network (LIN)
English language
27 pages
sale 15% off
Preview
sale 15% off
Preview

Standards Content (sample)

INTERNATIONAL ISO
STANDARD 17987-4
First edition
2016-09-01
Road vehicles — Local Interconnect
Network (LIN) —
Part 4:
Electrical physical layer (EPL)
specification 12 V/24 V
Véhicules routiers — Réseau Internet local (LIN) —
Partie 4: Spécification de la couche électrique physique (EPL) 12V/24V
Reference number
ISO 17987-4:2016(E)
ISO 2016
---------------------- Page: 1 ----------------------
ISO 17987-4:2016(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2016, Published in Switzerland

All rights reserved. Unless otherwise specified, 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
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2016 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 17987-4:2016(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 ......................................................................................................................................................................................................... 2

3.3 Abbreviated terms ............................................................................................................................................................................... 5

4 Conventions ............................................................................................................................................................................................................... 6

5 Electrical physical layer requirements .......................................................................................................................................... 6

5.1 Bit rate deviation ................................................................................................................................................................................... 6

5.1.1 12 V LIN systems: Parameters ............................................................................................................................. 6

5.1.2 24 V LIN systems: Parameters ............................................................................................................................. 7

5.2 Timing requirements ......................................................................................................................................................................... 9

5.2.1 Bit timing ................................................................................................................................................................................ 9

5.2.2 Synchronization procedure .................................................................................................................................... 9

5.2.3 Bit sample timing ............................................................................................................................................................ 9

5.3 Line driver/receiver ........................................................................................................................................................................11

5.3.1 General configuration ...............................................................................................................................................11

5.3.2 Definition of supply voltages for the physical interface ..............................................................11

5.3.3 Signal specification .....................................................................................................................................................12

5.3.4 12 V LIN systems: Electrical parameters .................................................................................................13

5.3.5 24 V LIN systems: Electrical parameters .................................................................................................17

5.3.6 Line characteristics .....................................................................................................................................................20

5.3.7 12 V LIN systems: performance in non-operation supply voltage range .....................20

5.3.8 24 V LIN systems: performance in non-operation supply voltage range .....................21

5.3.9 Performance during fault modes ....................................................................................................................21

5.3.10 ESD/EMI compliance ................................................................................................................................................21

Annex A (informative) LIN peripheral interface design considerations ......................................................................22

Bibliography .............................................................................................................................................................................................................................27

© ISO 2016 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO 17987-4:2016(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.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

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. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www.iso.org/patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment,

as well as information about ISO’s adherence to the World Trade Organization (WTO) principles in the

Technical Barriers to Trade (TBT) see the following URL: www.iso.org/iso/foreword.html.

The committee responsible for this document is ISO/TC 22, Road vehicles, Subcommittee SC 31, Data

communication.
A list of all parts in the ISO 17987 series can be found on the ISO website.
iv © ISO 2016 – All rights reserved
---------------------- Page: 4 ----------------------
ISO 17987-4:2016(E)
Introduction

ISO 17987 (all parts) 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 universal asynchronous receiver

transmitter (UART) based network. 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;

— 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 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 (all parts) 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 (all parts).

ISO 17987 (all parts) 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 17987 (all parts) provides all documents and references required to support the implementation of

the requirements related to the following.

— ISO 17987-1: This part provides an overview of the ISO 17987 (all parts) and structure along with

the use case definitions and a common set of resources (definitions, references) for use by all

subsequent parts.

— ISO 17987-2: 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.

— ISO 17987-3: 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.

© ISO 2016 – All rights reserved v
---------------------- Page: 5 ----------------------
ISO 17987-4:2016(E)

— ISO 17987-4: This part specifies the requirements for implementations of active hardware

components which are necessary to interconnect the protocol implementation.

— ISO/TR 17987-5: This part specifies the LIN application programmers interface (API) 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.

— ISO 17987-6: 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.

— ISO 17987-7: This part specifies tests to check the conformance of the LIN electrical physical layer

implementation (logical level of abstraction) according to this document.
vi © ISO 2016 – All rights reserved
---------------------- Page: 6 ----------------------
INTERNATIONAL STANDARD ISO 17987-4:2016(E)
Road vehicles — Local Interconnect Network (LIN) —
Part 4:
Electrical physical layer (EPL) specification 12 V/24 V
1 Scope

This document specifies the 12 V and 24 V electrical physical layers (EPL) of the LIN communications

system.

The electrical physical layer for LIN is designed for low-cost networks with bit rates up to 20 kbit/s to

connect automotive electronic control units (ECUs). The medium that is used is a single wire for each

receiver and transmitter with reference to ground.

This document includes the definition of electrical characteristics of the transmission itself and also

the documentation of basic functionality for bus driver devices.

All parameters in this document are defined for the ambient temperature range from −40 °C to 125 °C.

2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements 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.

IEC 61000-4-2, Electromagnetic compatibility (EMC) — Part 4-2: Testing and measurement techniques —

Electrostatic discharge immunity test
3 Terms, definitions, symbols and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at http://www.iso.org/obp
3.1.1
BR_Range_20K
LIN systems which operate at speeds up to 20 kbit/s
3.1.2
BR_Range_20K 12 V
12 V LIN systems which operate at speeds up to 20 kbit/s
3.1.3
BR_Range_20K 24 V
24 V LIN systems which operate at speeds up to 20 kbit/s
© ISO 2016 – All rights reserved 1
---------------------- Page: 7 ----------------------
ISO 17987-4:2016(E)
3.1.4
BR_Range_10K
LIN systems which operate at speeds up to 10 417 kbits/s
3.1.5
BR_Range_10K 12 V
12 V LIN systems which operate at speeds up to 10 417 kbits/s
3.1.6
BR_Range_10K 24 V
24 V LIN systems which operate at speeds up to 10 417 kbit/s
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
2 2 2 2
d V/dt second derivative of voltage (Volt per second )
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 bit rate
TOL_RES_MASTER
F master bit rate deviation from nominal bit rate in BR_Range_20K systems
TOL_RES_MASTER_A
F master bit rate deviation from nominal bit rate in BR_Range_10K systems
TOL_RES_MASTER_B
F slave bit rate deviation from nominal bit rate
TOL_RES_SLAVE
F slave bit rate deviation from nominal bit rate in BR_Range_20K systems
TOL_RES_SLAVE_A
F slave bit rate deviation from nominal bit rate in BR_Range_10K systems
TOL_RES_SLAVE_B
F slave node 1 bit rate deviation from nominal bit rate
TOL_RES_SLAVE_1
F slave node 2 bit rate deviation from nominal bit rate
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
TOL_SYNCH_A
in BR_Range_20K systems
F slave node bit rate deviation from master node bit rate after synchronization
TOL_SYNCH_B
in BR_Range_10K systems
2 © ISO 2016 – All rights reserved
---------------------- Page: 8 ----------------------
ISO 17987-4:2016(E)

F slave node 1 bit rate deviation from master node bit rate after synchronization

TOL_SYNCH_1

F slave node 2 bit rate deviation from master node bit rate after synchronization

TOL_SYNCH_2
F slave node bit rate deviation from nominal bit rate before synchronization
TOL_UNSYNCH
F slave node bit rate deviation from nominal bit rate before synchronization in
TOL_UNSYNCH_A
BR_Range_20K systems
F slave node bit rate deviation from nominal bit rate before synchronization in
TOL_UNSYNCH_B
BR_Range_10K systems
I current into the ECU bus line
BUS
I current limitation for driver dominant state driver on V = V into
BUS_LIM BUS BAT_max
ECU bus line
I current at ECU bus line when V is disconnected
BUS_NO_BAT BAT
I current at ECU bus line when V is disconnected
BUS_NO_GND GND_ECU
I current at ECU bus line when driver off (passive) at dominant LIN bus level
BUS_PAS_dom
I current at ECU bus line when driver off (passive) at recessive LIN bus level
BUS_PAS_rec
GND GND of ECU
Device
kΩ kilo ohm
kbit/s kilo bit per second
LEN total length of LIN bus line
BUS
LIN LIN network
Bus
ms millisecond
nF nano farad
pF pico farad
pF/m pico farad per meter (line capacitance)
R total bus-resistor including all slave and master resistors
BUS
R = R ||R ||R || to ||R
BUS MASTER SLAVE_1 SLAVE_2 SLAVE_N
R master resistor
MASTER
R pull-up resistor
pull_up
R slave resistor
SLAVE
t byte field synchronization time
BFS
t basic bit times
BIT
t earliest bit sample time
EBS
t propagation delay of receiver
rx_pd
© ISO 2016 – All rights reserved 3
---------------------- Page: 9 ----------------------
ISO 17987-4:2016(E)
t symmetry of receiver propagation delay rising edge propagation delay of
rx_sym
receiver
t latest bit sample time
LBS
t propagation delay time of receiving node 1 at falling (recessive to dominant)
rx_pdf(1)
LIN bus edge
t propagation delay time of receiving node 2 at falling (recessive to dominant)
rx_pdf(2)
LIN bus edge
t propagation delay time of receiving node 1 at rising (dominant to recessive)
rx_pdr(1)
LIN bus edge
t propagation delay time of receiving node 2 at rising (dominant to recessive)
rx_pdr(2)
LIN bus edge
t sample window repetition time
TH max. dominant threshold of receiving node (Volt)
Dom(max)
TH min. dominant threshold of receiving node (Volt)
Dom(min)
TH max. recessive threshold of receiving node (Volt)
Rec(max)
TH min. recessive threshold of receiving node (Volt)
Rec(min)
V voltage
V voltage at the anode of the diode
ANODE
V voltage across the ECU supply connectors
BAT
V voltage across the vehicle battery connectors
BATTERY
V voltage on the LIN bus
BUS
V centre point of receiver threshold
BUS_CNT
V receiver recessive voltage
BUS_rec
V voltage at the cathode of the diode
CATHODE
V battery ground voltage
GND_BATTERY
V voltage on the local ECU ground connector with respect to vehicle battery
GND_ECU
ground connector (V )
GND_BATTERY
V receiver hysteresis voltage
HYS
V recessive voltage
Rec
V voltage drop at the serial diodes
SerDiode
V battery shift
Shift_BAT
V difference between battery shift and GND shift
Shift_Difference
V GND shift
Shift_GND
V voltage at transceiver supply pins
SUP
4 © ISO 2016 – All rights reserved
---------------------- Page: 10 ----------------------
ISO 17987-4:2016(E)
V voltage which the device is not destroyed; no guarantee of correct operation
SUP_NON_OP
V receiver threshold voltage of the recessive to dominant LIN bus edge
th_dom
V receiver threshold voltage of the dominant to recessive LIN bus edge
th_rec
ΔF/F deviation of node bit rate from the master node bit rate
MASTER
ΔF/F deviation from nominal bit rate
Nom
τ time constant
Ω ohm
3.3 Abbreviated terms
AC alternate current
API application programmers interface
ASIC application specific integrated circuit
BFS byte field synchronization
DC direct current
EBS earliest bit sample
ECU electronic control unit
EMC electromagnetic compatibility
EMI electromagnetic interference
EPL electrical physical layer
ESD electrostatic discharge
EVT event
GND ground
LBS latest bit sample
Max. maximum
Min. minimum
OSI open systems interconnection
RC RC time constant τ (τ = C × R )
BUS BUS
RX Rx pin of the transceiver
RXD receive data
SR sample window repetition
TRX transceiver
Tx Tx pin of the transceiver
© ISO 2016 – All rights reserved 5
---------------------- Page: 11 ----------------------
ISO 17987-4:2016(E)
TXD transmit data
Typ. typical
UART universal asynchronous receiver transmitter
4 Conventions

ISO 17987 (all parts) and ISO 14229-7 are based on the conventions specified in the OSI Service

Conventions (see ISO/IEC 10731) as they apply for physical layer, protocol, network and transport

protocol and diagnostic services.
5 Electrical physical layer requirements
5.1 Bit rate deviation

The bit rate deviation of the LIN medium describes the bit rate deviation from a referenced bit rate. It is

the sum of the following parameters:

— inaccuracy of setting the bit rate (systematic failure due to granularity of the configurable bit rate);

— clock deviation over temperature and supply voltage range;

— clock source stability of the slave node starting from the end of the sync byte field up to the end of

the entire LIN frame (last sampled bit) when performing synchronization;
— bit time measurement failure of the slave node;

— clock source stability of the master node starting from the end of the sync byte field up to the end of

the entire LIN frame (last transmitted bit).

On-chip clock may achieve a frequency deviation of better than ±14 % with internal calibration. This

bit rate deviation better than ±14 % is sufficient to detect a break field in the message stream. The

subsequent bit rate adaptation using the sync byte field ensures the proper reception and transmission

of the message. The on-chip oscillator shall allow for accurate bite rate measurement and generation for

the remainder of the message frame, taking into account effects of anything, which affects the bit rate,

such as temperature and voltage drift during operation.

The bit rates on the LIN bus are specified in the range of 1 kbit/s to 20 kbit/s. The specific bit rate used

on a LIN bus is defined as the nominal bit rate, F .
Nom

In case a non-LIN electrical physical layer (e.g. ISO 11898-1, ISO 11898-2) is used, the bit rate may have

to be adjusted.
5.1.1 12 V LIN systems: Parameters
Table 1 defines the bit rate deviation from nominal bit rate.
6 © ISO 2016 – All rights reserved
---------------------- Page: 12 ----------------------
ISO 17987-4:2016(E)
Table 1 — Bit rate deviation from nominal bit rate
Number Bit rate deviation Name ΔF/F
Nom
Param 1 Master node (deviation from nominal bit rate) F <±0,5 %
TOL_RES_
MASTER

Param 2 Slave node without making use of synchronization (deviation from F <±1,5 %

TOL_RES_SLAVE
nominal bit rate)

Param 3 Deviation of slave node bit rate from the nominal bit rate before F <±14 %

TOL_UNSYNCH
synchronization; relevant for nodes making use of synchronization
and direct break detection.
This parameter is microprocessor-based nodes with sync/break
detection that is triggering the auto-bauding processing in software.
It insures that the break is detected.
Table 2 defines the slave node bit rate deviation from master node bit rate.
Table 2 — Slave node bit rate deviation from master node bit rate
Number Bit rate deviation Name ΔF/F
MASTER

Param 4 Deviation of slave node bit rate from the master node bit rate after F <±2 %

TOL_SYNCH
synchronization; relevant for nodes making use of synchronization;
any slave node shall stay within this deviation for all fields of a
frame which follow the sync byte field.
Table 3 defines the bit rate deviation for slave to slave communication.
Table 3 — Bit rate deviation for slave to slave communication
Number Bit rate deviation Name ΔF/F
MASTER
Param 5 For communication between any two nodes (i.e. data stream F <±2 %
TOL_SLAVE_to_
from one slave to another slave), their bit rate shall not differ by
SLAVE
more than F . The following condition shall be
TOL_SLAVE_to_SLAVE
checked for:
a) |F − F | < F ;
TOL_RES_SLAVE_1 TOL_RES_SLAVE_2 TOL_SLAVE_to_SLAVE
b) |F − F | < F ;
TOL_SYNCH_1 TOL_SYNCH_2 TOL_SLAVE_to_SLAVE
c) |(F + F ) − F |
TOL_RES_MASTER TOL_SYNCH_1 TOL_RES_SLAVE_2
< F .
TOL_SLAVE_to_SLAVE
5.1.2 24 V LIN systems: Parameters

The required accuracy is dependent on the used bit rate range. See Table 15 and also ISO 17987-2.

Table 4 defines the bit rate deviation from nominal bit rate in BR_Range_20K systems.

© ISO 2016 – All rights reserved 7
---------------------- Page: 13 ----------------------
ISO 17987-4:2016(E)
Table 4 — Bit rate deviation from nominal bit rate in BR_Range_20K systems
Number BR_Range_20K bit rate deviation Name ΔF/F
Nom
Param 39 master node
TOL_RES_
(deviation from nominal bit rate. The nominal bit rate F is <±0,3 %
Nom
MASTER_A
defined in the LIN description file).
Param 40 slave node without making use of synchronization (deviation
from nominal bit rate)
F <±0,3 %
TOL_RES_SLAVE_A
For communication between any two nodes, their bit rate shall
not differ by more than ±0,6 %.
Param 41 deviation of slave node bit rate from the nominal bit rate before
synchronization; relevant for nodes making use of F <±14 %
TOL_UNSYNCH_A
synchronization and direct break field detection.

Table 5 defines the bit rate deviation for slave nodes from master node in BR_Range_20K systems.

Table 5 — Bit rate deviation for slave nodes from master node in BR_Range_20K systems

Number BR_Range_20K bit rate deviation Name ΔF/F
MASTER
Param 42 Deviation of slave node bit rate from the master node bit rate
after synchronization; relevant for nodes making use of
synchronization; any slave node shall stay within this F <±0,6 %
TOL_SYNCH_A
deviation for all fields of a frame which follow the sync byte
field.
Param 43 For communication between any two nodes (i.e. data stream
from one slave to another slave), their bit rate shall not differ
by more than F . The following condition
TOL_SLAVE_to_SLAVE
shall be checked for:
TOL_SLAVE_to_
a) |F − F | < F ; <±0,6 %
TOL_RES_SLAVE_1 TOL_RES_SLAVE_2 TOL_SLAVE_to_SLAVE
SLAVE
b) |F − F | < F ;
TOL_SYNCH_1 TOL_SYNCH_2 TOL_SLAVE_to_SLAVE
c) |(F + F )− F |
TOL_RES_MASTER_A TOL_SYNCH_1 TOL_RES_SLAVE_2
< F .
TOL_SLAVE_to_SLAVE

Table 6 defines the Bit rate deviation from nominal bit rate in BR_Range_10K systems.

Table 6 — Bit rate deviation from nominal bit rate in BR_Range_10K systems
Number BR_Range_10K bit rate deviation Name ΔF/F
Nom
Param 44 master node
TOL_RES_
(deviation from nominal bit rate. The nominal bit rate F is <±0,5 %
Nom
MASTER_B
defined in the LDF).
Param 45 slave node without making use of synchronization (deviation
from nominal bit rate)
F <±1,5 %
TOL_RES_SLAVE_B
For communication between any two nodes, their bit rate
shall not differ by more than ±2,0 %.
Param 46 deviation of slave node bit rate from the nominal bit rate
before synchronization; relevant for nodes making use of F <±14 %
TOL_UNSYNCH_B
synchronization and direct break field detection.

Table 7 defines the bit rate deviation for slave nodes from master node in BR_Range_10K systems.

8 © ISO 2016 – All rights reserved
---------------------- Page: 14 ----------------------
ISO 17987-4:2016(E)

Table 7 — Bit rate deviation for slave nodes from master node in BR_Range_10K systems

Number BR_Range_10K bit rate deviation Name ΔF/F
MASTER
Param 47 Deviation of slave node bit rate from the master node bit
rate after synchronization; relevant for nodes making use of
synchronization; any slave node shall stay within this F <±2,0 %
TOL_SYNCH_B
deviation for all fields of a frame which follow the sync
byte field.
Param 48 For communication between any two nodes (i.e. data stream
from one slave to another slave), their bit rate shall not differ
by more than F . The following condition
TOL_SLAVE_to_SLAVE
shall be checked for:
TOL_SLAVE_to_
a) |F − F | < F ; <±2,0 %
TOL_RES_SLAVE_1 TOL_RES_SLAVE_2 TOL_SLAVE_to_SLAVE
SLAVE
b) |F − F | < F :
TOL_SYNCH_1 TOL_SYNCH_2 TOL_SLAVE_to_SLAVE
c) |(F + F ) − F |
TOL_RES_MASTER_B TOL_SYNCH_1 TOL_RES_SLAVE_2
< F .
TOL_SLAVE_to_SLAVE
5.2 Timing requirements
5.2.1 Bit timing

If not otherwise stated, all bit times in this document use the bit timing of the master node as a reference.

5.2.2 Synchronization procedure

The sync byte field consists of the fixed data 55 inside a byte field. The synchronization procedure

shall be based on time measurement between falling edges of the pattern. The falling edges are

available in distances of 2 bit, 4 bit, 6 bit and 8 bit times which allows a simple calculation of the basic

bit times, t .
BIT
Figure 1 shows the sync byte field.
Figure 1 — Sync byte field
5.2.3 Bit sample timing

The bits of a byte field shall be sampled according to the following specification. In Figure 2, the bit

sample timing of a byte field
...

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
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 17987-4.2:2015(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION. ISO 2015
---------------------- Page: 1 ----------------------
ISO/DIS 17987-4.2:2015(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2015, Published in Switzerland

All rights reserved. Unless otherwise specified, 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
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2015 – All rights reserved
---------------------- Page: 2 ----------------------
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 2015 – All rights reserved iii
---------------------- Page: 3 ----------------------
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
---------------------- Page: 4 ----------------------
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 2015 – All rights reserved v
---------------------- Page: 5 ----------------------
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
---------------------- Page: 6 ----------------------
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 2015 – All rights reserved 1
---------------------- Page: 7 ----------------------
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
---------------------- Page: 8 ----------------------
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 bit rate deviation from master node bit rate after synchronization

TOL_SYNCH_2
F slave node bit rate deviation from nominal bit rate before synchronization
TOL_UNSYNCH
F slave node bit rate deviation from nominal bit rate before synchronization in
TOL_UNSYNCH_A
BR_Range_20K systems
F slave node bit rate deviation from nominal bit rate before synchronization in
TOL_UNSYNCH_B
BR_Range_10K systems
I current into the ECU bus line
BUS
I current limitation for driver dominant state driver on V = V into ECU bus line
BUS_LIM BUS BAT_max
I current at ECU bus line when V is disconnected
BUS_NO_BAT BAT
I current at ECU bus line when V is disconnected
BUS_NO_GND GND_ECU
I current at ECU bus line when driver off (passive) at dominant LIN bus level
BUS_PAS_dom
I current at ECU bus line when driver off (passive) at recessive LIN bus level
BUS_PAS_rec
GND GND of ECU
Device
KΩ kilo ohm
kbit/s kilo bit per second
LEN total length of LIN bus line
BUS
LIN LIN network
Bus
ms millisecond
nF nano farad
pF pico farad
pF/m pico farad per meter (line capacitance)
R total bus-resistor including all slave and master resistors
BUS
R = R || R || R || to || R
BUS MASTER SLAVE_1 SLAVE_2 SLAVE_N
R master resistor
MASTER
R pull-up resistor
pull_up
R slave resistor
SLAVE
t byte field synchronization time
BFS
t basic bit times
BIT
t earliest bit sample time
EBS
t propagation delay of receiver
rx_pd
© ISO 2015 – All rights reserved 3
---------------------- Page: 9 ----------------------
ISO/DIS 17987-4.2

t symmetry of receiver propagation delay rsising edgepropagation delay of receiver

rx_sym
t latest bit sample time
LBS

t propagation delay time of receiving node 1 at falling (recessive to dominant ) LIN bus

rx_pdf(1)
edge

t propagation delay time of receiving node 2 at falling (recessive to dominant ) LIN bus

rx_pdf(2)
edge

t propagation delay time of receiving node 1 at rising (dominant to recessive) LIN bus

rx_pdr(1)
edge

t propagation delay time of receiving node 2 at rising (dominant to recessive) LIN bus

rx_pdr(2)
edge
t sample window repetition time
TH max. dominant threshold of receiving node (Volt)
Dom(max)
TH min. dominant threshold of receiving node (Volt)
Dom(min)
TH max. recessive threshold of receiving node (Volt)
Rec(max)
TH min. recessive threshold of receiving node (Volt)
Rec(min)
V voltage
V voltage at the anode of the diode
ANODE
V voltage across the ECU supply connectors
BAT
V voltage across the vehicle battery connectors
BATTERY
V voltage on the LIN bus
BUS
V center point of receiver threshold
BUS_CNT
V receiver recessive voltage
BUS_rec
V voltage at the cathode of the diode
CATHODE
V battery ground voltage
GND_BATTERY

V voltage on the local ECU ground connector with respect to vehicle battery ground

GND_ECU
connector (V )
GND_BATTERY
V receiver hysteresis voltage
HYS
V recessive voltage
Rec
SerDiode
voltage drop at the serial diodes
V battery shift
Shift_BAT
V difference between battery shift and GND shift
Shift_Difference
V GND shift
Shift_GND
4 © ISO 2015 – All rights reserved
---------------------- Page: 10 ----------------------
ISO/DIS 17987-4.2
V voltage at transceiver supply pins
SUP
V voltage which the device is not destroyed; no guarantee of correct operation
SUP_NON_OP
V receiver threshold voltage of the recessive to dominant LIN bus edge
th_dom
V receiver threshold voltage of the dominant to recessive LIN bus edge
th_rec
ΔF / F deviation of node bit rate from the master node bit rate
MASTER
ΔF / F deviation from nominal bit rate
Nom
τ time constant
Ω ohm
40 3.3 Abbreviated terms
AC alternate current
API application programmers interface
ASIC application specific integrated circuit
BFS byte field synchronization
DC direct current
EBS earliest bit sample
EMC electromagnetic compatibility
EMI electromagnetic interference
EPL electrical physical layer
ESD electrostatic discharge
EVT event
GND ground
LBS latest bit sample
Max maximum
Min minimum
OSI open systems interconnection
RC RC time constant τ (τ = C * R )
BUS BUS
RX Rx pin of the transceiver
RXD receive data
© ISO 2015 – All rights reserved 5
---------------------- Page: 11 ----------------------
ISO/DIS 17987-4.2
SR sample window repetition
TRX transceiver
Tx Tx pin of the transceiver
TXD transmit data
Typ. typical
UART universal asynchronous receiver transmitter
41 4 Conventions

42 ISO 17987 and ISO 14229-7 [8] are based on the conventions specified in the OSI Service Conventions

43 (ISO/IEC 10731) [2] as they apply for physical layer, protocol, network & transport protocol and diagnostic

44 services.
45 5 Electrical physical layer requirements
46 5.1 Bit rate deviation

47 The bit rate deviation of the LIN medium describes the bit rate deviation from a referenced bit rate. It is the

48 sum of the following parameters:

49  Inaccuracy of setting the bit rate (systematic failure due to granularity of the configurable bit rate)

50  Clock deviation over temperature and supply voltage range

51  Clock source stability of the slave node starting from the end of the sync byte field up to the end of the

52 entire LIN frame (last sampled bit) when performing synchronization.
53  Bit time measurement failure of the slave node

54  Clock source stability of the master node starting from the end of the sync byte field up to the end of the

55 entire LIN frame (last transmitted bit)

56 On-chip clock may achieve a frequency deviation of better than ± 14 % with internal calibration. This bit rate

57 deviation better than ± 14 % is sufficient to detect a break field in the message stream. The subsequent bit

58 rate adaptation using the sync byte field ensures the proper reception and transmission of the message. The

59 on-chip oscillator shall allow for accurate bite rate measurement and generation for the remainder of the

60 message frame, taking into account effects of anything, which affects the bit rate, such as temperature and

61 voltage drift during operation.

62 The bit rates on the LIN bus are specified in the range of 1 to 20 kbit/s. The specific bit rate used on a LIN bus

63 is defined as the nominal bit rate F .
Nom

64 In case a non-LIN electrical physical layer (e.g. ISO 11898-1, ISO 11898-2) is used, the bit rate may have to

65 be adjusted.
66 5.1.1 12 V LIN systems: Parameters
67 Table 1 defines the bit rate deviation from nominal bit rate.
6 © ISO 2015 – All rights reserved
---------------------- Page: 12 ----------------------
ISO/DIS 17987-4.2
68 Table 1 — Bit rate deviation from nominal bit rate
Number Bit rate deviation Name ΔF/F .
Nom
Param 1 Master node (deviation from nominal bit rate) F < ± 0,5 %
TOL_RES_MASTER

Param 2 Slave node without making use of synchronization (deviation from F < ± 1,5 %

TOL_RES_SLAVE
nominal bit rate)

Param 3 Deviation of slave node bit rate from the nominal bit rate before F < ± 14 %

TOL_UNSYNCH
synchronization; relevant for nodes making use of synchronization and
direct break detection.
This parameter is microprocessor based nodes with sync/break detection
that is triggering the auto-bauding processing in software. It insures that
the break is detected.
70 Table 2 defines the slave node bit rate deviation from master node bit rate.
71 Table 2 — Slave node bit rate deviation from master node bit rate
Number Bit rate deviation Name ΔF/F
Master

Param 4 Deviation of slave node bit rate from the master node bit rate after F < ± 2 %

TOL_SYNCH
synchronization; relevant for nodes making use of synchronization; any
slave node shall stay within this deviation for all fields of a frame which
follow the sync byte field.
73 Table 3 defines the bit rate deviation for slave to slave communication.
74 Table 3 — Bit rate deviation for slave to slave communication
Number Bit rate deviation Name ΔF/F
Master

Param 5 For communication between any two nodes (i.e. data stream from one F < ± 2 %

TOL_SLAVE_to_SLAVE
slave to another slave) their bit rate shall not differ by more than
F . The following condition shall be checked for:
TOL_SLAVE_to_SLAVE
a) |F - F | < F
TOL_RES_SLAVE_1 TOL_RES_SLAVE_2 TOL_SLAVE_to_SLAVE
b) |F - F | < F
TOL_SYNCH_1 TOL_SYNCH_2 TOL_SLAVE_to_SLAVE
c) |(F + F ) - F |
TOL_RES_MASTER TOL_SYNCH_1 TOL_RES_SLAVE_2
< F
TOL_SLAVE_to_SLAVE
76 5.1.2 24 V LIN systems: Parameters

77 The required accuracy is dependent on the used bitrate range. See Table 15 and also ISO 17987-2.

78 Table 4 defines the bit rate deviation from nominal bitrate in BR_Range_20K systems.

79 Table 4 — Bit rate deviation from nominal bitrate in BR_Range_20K systems
Number BR_Range_20K bit rate deviation Name ΔF / F
Nom.
Param 39 master node
(deviation from nominal bit rate. The nominal bit rate F is defined F < ± 0,3 %
Nom TOL_RES_MASTER_A
in the LIN description file).
© ISO 2015 – All rights reserved 7
---------------------- Page: 13 ----------------------
ISO/DIS 17987-4.2
Param 40 slave node without making use of synchronization (deviation from
nominal bit rate)
F < ± 0,3 %
TOL_RES_SLAVE_A
For communication between any two nodes their bit rate shall not
differ by more than ± 0,6 %.
Param 41 deviation of slave node bit rate from the nominal bit rate before
synchronization; relevant for nodes making use of synchronization F < ± 14 %
TOL_UNSYNCH_A
and direct break field detection.

81 Table 5 defines the bit rate deviation for slave nodes from master node in BR_Range_20K systems.

82 Table 5 — Bit rate deviation for slave nodes from master node in BR_Range_20K systems

Number BR_Range_20K bit rate deviation Name ΔF / F
MASTER
Param 42 Deviation of slave node bit rate from the master node bit rate after
synchronization; relevant for nodes making use of
F < ± 0,6 %
TOL_SYNCH_A
synchronization; any slave node shall stay within this deviation for
all fields of a frame which follow the sync byte field.
Param 43 For communication between any two nodes (i.e. data stream from
one slave to another slave) their bit rate shall not differ by more
than F . The following condition shall be checked
TOL_SLAVE_to_SLAVE
for:
a) |F - F | < F
TOL_RES_SLAVE_1 TOL_RES_SLAVE_2 TOL_SLAVE_to_SLAVE F < ± 0,6 %
TOL_SLAVE_to_SLAVE
b) |F - F | < F
TOL_SYNCH_1 TOL_SYNCH_2 TOL_SLAVE_to_SLAVE
c) |(F + F ) - F |
TOL_RES_MASTER_A TOL_SYNCH_1 TOL_RES_SLAVE_2
< F
TOL_SLAVE_to_SLAVE

84 Table 6 defines the Bit rate deviation from nominal bitrate in BR_Range_10K systems.

85 Table 6 — Bit rate deviation from nominal bitrate in BR_Range_10K systems
Number BR_Range_10K bit rate deviation Name ΔF / F
Nom
Param 44 master node
(deviation from nominal bit rate. The nominal bit rate F is F < ± 0,5 %
Nom TOL_RES_MASTER_B
defined in the LDF).
Param 45 slave node without making use of synchronization (deviation from
nominal bit rate)
F < ± 1,5 %
TOL_RES_SLAVE_B
For communication between any two nodes their bit rate shall not
differ by more than ± 2,0%.
Param 46 deviation of slave node bit rate from the nominal bit rate before
synchronization; relevant for nodes making use of synchronization F < ± 14 %
TOL_UNSYNCH_B
and direct break field detection.

87 Table 7 defines the bit rate deviation for slave nodes from master node in BR_Range_10K systems.

8 © ISO 2015 – All rights reserved
---------------------- Page: 14 ----------------------
ISO/DIS 17987-4.2

88 Table 7 — Bit rate deviation for slave nodes from master node in BR_Range_10K systems

Number BR_Range_10K bit rate deviation Name ΔF / F
MASTER
Param 47 Deviation of slave node bit rate from the master node bit rate after
synchronization; relevant for nodes making use of
F < ± 2,0 %
TOL_SYNCH_B
synchronization; any slave node shall stay within this deviation for
all fields of a frame which follow the sync byte field.
Param 48 For communication between any two nodes (i.e. data stream from
one slave to another slave) their bit rate shall not differ by more
than F . The following condition shall be checked
TOL_SLAVE_to_SLAVE
for:
a) |F - F | < F
TOL_RES_SLAVE_1 TOL_RES_SLAVE_2 TOL_SLAVE_to_SLAVE F < ± 2,0 %
TOL_SLAVE_to_SLAVE
b) |F - F | < F
TOL_SYNCH_1 TOL_SYNCH_2 TOL_SLAVE_to_SLAVE
c) |(F + F ) - F |
TOL_RES_MASTER_B TOL_SYNCH_1 TOL_RES_SLAVE_2
< F
TOL_SLAVE_to_SLAVE
90 5.2 Timing requirements
91 5.2.1 Bit timing

92 If not otherwise stated, all bit times in this document use the bit timing of the master node as a reference.

93 5.2.2 Synchronization procedure

94 The sync byte field consists of the fixed data 55 inside a byte field. The synchronization procedure shall be

95 based on time measurement between falling edges of the pattern. The falling edges are available in distances

96 of 2, 4, 6 and 8 bit times which allows a simple calculation of the basic bit times t .

BIT
97 Figure 1 shows the sync byte field.
Sync byte field
8 t
BIT
2 t 2 t 2 t 2 t
BIT BIT BIT BIT
start stop
2 4
0 1 3
5 6 7
bit bit
100 Figure 1 — Sync byte field
101
© ISO 2015 – All rights reserved 9
---------------------- Page: 15 ----------------------
ISO/DIS 17987-4.2
102 5.2.3 Bit sample timing

103 The bits of a byte field shall be sampled according to the following specification. In Figure 2 the bit sample

104 timing of a byte field is illustrated. The corresponding timing parameters are listed in Table 8.

105 A byte field shall be synchronized at the falling edge of the start bit. The byte field synchronization (BFS) shall

106 have an accuracy of t .
BFS

107 All methods for start bit sampling that meet the byte field synchronization t are allowed.

BFS

108 After the byte field synchronization on the falling edge of the start bit the data bit itself shall be sampled within

109 the window between the earliest bit sample (EBS) time t and the latest bit sample (LBS) time t . The

EBS LBS

110 latest bit sample time t depends on the accuracy of the byte field synchronization t . The dependency

LBS BFS
111 between t and t is given in equation (1)
LBS BFS
Definition of equation (1)
t = 10/16 t - t
LBS BIT BFS
112

113 The following bits shall be sampled within the same range as the sample window of the first data bit with the

114 sample window repetition time t respectively. The sample window repetition time t is specified from the

SR SR
115 EBS of the former bit (n-1) to the EBS of the current bit; see equation (2).
Definition of equation (2)
t = t - t = t - t = t
SR EBS(n) EBS(n-1) LBS(n) LBS(n-1) BIT
116
117 Table 8 — Bit sample timing
Number Parameter Min. Typ. Max. Unit Comment / condition
Param 6 t --- 1/16 2/16 t Value of accuracy of the byte field detection
BFS BIT
Param 7 t 7/16 --- --- t Earliest bit sample time, t ≤ t
EBS BIT EBS LBS
Param 8 t
LBS --- --- --- tBIT Latest bit sample, see equation (1), tLBS ≥ tEBS
118

119 For devices, which make use of more than one sample per bit, the bit sample majority

...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.