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

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ISO/DIS 17987-4.2:2015(E)

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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

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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
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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.

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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.

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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
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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
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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
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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
SR
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
V
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
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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
39
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
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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.
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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.
69
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.
72
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
75
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).
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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.
80
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
83
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.
86
87 Table 7 defines the bit rate deviation for slave nodes from master node in BR_Range_10K systems.
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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
89
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
16
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.
98
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
99
100 Figure 1 — Sync byte field
101
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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
...