IEC TS 61375-2-4:2017

IEC TS 61375-2-4 ®
Edition 1.0 2017-02
TECHNICAL
SPECIFICATION
colour
inside
Electronic railway equipment – Train communication network (TCN) –
Part 2-4: TCN application profile

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IEC TS 61375-2-4 ®
Edition 1.0 2017-02
TECHNICAL
SPECIFICATION
colour
inside
Electronic railway equipment – Train communication network (TCN) –

Part 2-4: TCN application profile

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 45.060.01 ISBN 978-2-8322-3818-9

– 2 – IEC TS 61375-2-4:2017 © IEC 2017
CONTENTS
FOREWORD . 6
INTRODUCTION . 8
1 Scope . 9
2 Normative references . 10
3 Terms, definitions, abbreviated terms, acronyms and conventions . 11
3.1 Terms and definitions . 11
3.2 Abbreviated terms and acronyms . 13
3.3 Conventions . 14
3.3.1 Base of numeric values . 14
3.3.2 Naming conventions . 14
3.3.3 State diagram conventions . 15
3.3.4 Elementary data types . 15
3.3.5 Derived data types . 15
4 Distributed train applications . 15
4.1 General . 15
4.2 Function interface for remote control . 15
4.3 General application architecture . 16
4.4 Architecture model . 17
4.5 Assignment of function leader and function follower . 18
4.6 Communication flow . 18
5 Addressing and data format . 19
5.1 General . 19
5.2 Function data unit . 21
5.2.1 General . 21
5.2.2 Function identification . 22
5.2.3 Channel identification . 22
5.2.4 Function instance information . 24
5.2.5 Function control information. 24
5.2.6 Function life sign . 25
5.2.7 Function data length . 25
5.2.8 Function data set . 25
5.2.9 Sequence numbers . 25
6 Transversal functions . 28
6.1 General . 28
6.2 Function train mode . 28
6.2.1 Train mode breakdown structure . 28
6.2.2 Train mode propagation . 30
6.2.3 Operation modes . 30
6.2.4 Train modes . 32
6.2.5 Other train modes . 40
6.2.6 Parameter train_mode . 44
7 Application profiles . 48
7.1 Door system application profile . 48
7.1.1 Scope . 48
7.1.2 Door system breakdown structure . 49
7.1.3 Door types . 50

7.1.4 Door application functional breakdown system . 52
7.1.5 Door application degraded mode . 52
7.1.6 Door application special mode . 53
7.1.7 Door system interaction . 53
7.1.8 Side selective operation. 60
7.1.9 Door application behaviour . 61
Annex A (normative) Profile data definitions. 78
A.1 Engineering units . 78
A.2 Function identification . 79
Bibliography . 88

Figure 1 – IEC TS 61375-2-4 as a link between the functions and the applications . 10
Figure 2 – Remote control of a process via the function interface . 16
Figure 3 – Architecture of a distributed application . 16
Figure 4 – Architecture model of a distributed application . 17
Figure 5 – Communication flow in the distributed application . 19
Figure 6 – Example function instances and their relations . 20
Figure 7 – Mapping of function instance relations to communication infrastructure . 20
Figure 8 – Function data units embedded in TRDP . 21
Figure 9 – Structure of function data unit . 21
Figure 10 – Structure of function data unit header . 22
Figure 11 – Illustration of channel relations . 23
Figure 12 – Example train composition to illustrate sequence numbers . 26
Figure 13 – Example sequence numbers in counting area train . 26
Figure 14 – Example sequence numbers in counting area closed train . 27
Figure 15 – Example sequence numbers in counting area consist . 27
Figure 16 – Example functional sequence numbers of vehicles in counting area train . 28
Figure 17 – Distribution structure for the function train mode . 29
Figure 18 – Component structure of function train mode . 29
Figure 19 – Example operation modes state diagram . 32
Figure 20 – Example train modes state diagram. 40
Figure 21 – Parameter train_mode . 44
Figure 22 – Distribution structure of the door application . 49
Figure 23 – Architecture of the door system . 49
Figure 24 – Door types . 50
Figure 25 – Communication path for entry doors . 51
Figure 26 – Communication path for interconnecting doors . 51
Figure 27 – Communication path for entry doors of sleeping cars . 51
Figure 28 – Communication path for interconnecting doors of sleeping cars . 52
Figure 29 – Communication flow of triggers for entry doors . 54
Figure 30 – Communication flow of triggers for neighbouring interconnecting doors . 57
Figure 31 – Neighbouring consist DCUs for neighbouring interconnecting doors . 58
Figure 32 – Communication flow of triggers for control of interconnecting doors of
sleeping cars . 59

– 4 – IEC TS 61375-2-4:2017 © IEC 2017
Figure 33 – Side selective parameterization of triggers . 61
Figure 34 – State machine structure of DCU and consist DCU . 62
Figure 35 – DCU state diagram for entry doors . 64
Figure 36 – DCU state diagram for neighbouring interconnecting doors . 67
Figure 37 – DCU state diagram for interconnecting doors of sleeping cars . 68
Figure 38 – Consist DCU state diagram for entry doors . 69
Figure 39 – Consist DCU state diagram for neighbouring interconnecting doors . 71
Figure 40 – Consist DCU state diagram for interconnecting doors of sleeping cars . 73
Figure 41 – Train DCU state diagram . 75

Table 1 – Channel groups . 23
Table 2 – Control information . 25
Table 3 – OperationModes . 45
Table 4 – TrainModes . 46
Table 5 – OtherTrainMode . 48
Table 6 – Operation scenarios . 52
Table 7 – Door application degraded mode . 53
Table 8 – Door application special mode . 53
Table 9 – Triggers between TCMS and train DCU . 55
Table 10 – Local triggers for the train DCU . 55
Table 11 – Triggers between train DCU and consist DCU . 55
Table 12 – Triggers between consist DCU and DCU for entry doors . 56
Table 13 – Local triggers for the DCU . 56
Table 14 – Triggers between DCU and door. 56
Table 15 – Triggers between consist DCU and consist DCU for neighbouring
interconnecting doors . 57
Table 16 – Triggers between consist DCU and DCU for neighbouring interconnecting
doors . 58
Table 17 – Triggers between consist DCU and consist DCU for interconnecting doors
of sleeping cars . 59
Table 18 – Triggers between consist DCU and DCU for interconnecting doors of
sleeping cars . 60
Table 19 – DCU state definitions . 63
Table 20 – DCU triggers for entry doors . 65
Table 21 – DCU operations for entry doors . 66
Table 22 – DCU state definitions for neighbouring interconnecting doors . 66
Table 23 – DCU state definitions for interconnecting doors of sleeping cars . 67
Table 24 – Consist DCU state definitions for entry doors . 68
Table 25 – Additional consist DCU state definitions for entry doors of sleeping cars . 69
Table 26 – Consist DCU Triggers for entry doors . 70
Table 27 – Consist DCU Conditions for entry doors . 70
Table 28 – Consist DCU Operations for entry doors . 71
Table 29 – Consist DCU state definitions for neighbouring interconnecting doors . 71
Table 30 – Consist DCU Triggers for neighbouring interconnecting doors . 72

Table 31 – Consist DCU Operations for neighbouring interconnecting doors . 72
Table 32 – Consist DCU state definitions for interconnecting doors of sleeping cars . 72
Table 33 – Consist DCU Triggers for interconnecting doors of sleeping cars . 73
Table 34 – Consist DCU Operations for interconnecting doors of sleeping cars . 73
Table 35 – Train DCU state definitions . 74
Table 36 – Train DCU triggers . 76
Table 37 – Train DCU conditions . 76
Table 38 – Train DCU operations . 77
Table A.1 – Physical quantities (e.g. 16 bit integer type) . 78
Table A.2 – Physical quantities (other data types) . 79
Table A.3 – List of function identifiers . 80
Table A.4 – List of sub-function identifiers and instance info . 83

– 6 – IEC TS 61375-2-4:2017 © IEC 2017
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRONIC RAILWAY EQUIPMENT –
TRAIN COMMUNICATION NETWORK (TCN) –

Part 2-4: TCN application profile

FOREWORD
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
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9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
The main task of IEC technical committees is to prepare International Standards. In
exceptional circumstances, a technical committee may propose the publication of a technical
specification when
• the required support cannot be obtained for the publication of an International Standard,
despite repeated efforts, or
• the subject is still under technical development or where, for any other reason, there is the
future but no immediate possibility of an agreement on an International Standard.
Technical specifications are subject to review within three years of publication to decide
whether they can be transformed into International Standards.
IEC TS 61375-2-4, which is a technical specification, has been prepared by IEC technical
committee 9: Electrical equipment and systems for railways, in collaboration with UIC.

The text of this technical specification is based on the following documents:
Enquiry draft Report on voting
9/2093/DTS 9/2150A/RVC
Full information on the voting for the approval of this technical specification can be found in
the report on voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 61375 series, published under the general title Electronic railway
equipment – Train communication network (TCN), can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC website under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• transformed into an International standard,
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
– 8 – IEC TS 61375-2-4:2017 © IEC 2017
INTRODUCTION
IEC TS 61375-2-4 defines the application profiles of the Train Communication Network in
order to achieve communication between software applications throughout consist networks
defined in IEC 61375-1 and the train backbone defined in IEC 61375-2-5.
This part of IEC 61375 defines the requirements for the applications communicating via the
data transmission equipment of the consists throughout the consist networks and the train
backbones.
The purpose of this part of IEC 61375 is to:
• fully document the communication requirements for all train applications, align them and
set them out in standard form,
• provide guidelines for the technical solution of communication between software
applications residing on the same or on different consists, which are part of a train, and
which are connected to the consist networks and the train backbones in scope,
• define train applications for certain functionalities, which are in scope of this part of
IEC 61375.
ELECTRONIC RAILWAY EQUIPMENT –
TRAIN COMMUNICATION NETWORK (TCN) –

Part 2-4: TCN application profile

1 Scope
This part of IEC 61375 applies to the applications in trains, i.e. it covers the application profile
for functions belonging to the Train Control and Monitoring System (TCMS). The application
profile is based on the TCN communication system for the data communication between
consists of the said trains. This document provides for a data interface with parameters and
addressing of TCMS functions based on the communication profile laid out in IEC 61375-2-3.
This document is applicable in rolling stock requiring interoperable coupling and uncoupling.
This part of IEC 61375 may be additionally applicable to closed trains and multiple unit trains
when so agreed between purchaser and supplier.
The applicability of this part of IEC 61375 to the train communication network technologies as
defined allows for interoperability of individual consists within trains.
The data communication systems inside consists are not covered by this document and are
given only as example solutions to cope with the said TCN. In any case, proof of compatibility
between a proposed train backbone and a proposed consist network will have to be brought
by the supplier.
Special backup functions, which are used in cases when the train backbone is in a degraded
condition are not in the scope of this document.

– 10 – IEC TS 61375-2-4:2017 © IEC 2017
Operator (e.g. driver, train staff)
applications
application services
IEC TS 61375-2-4 TCN application profile
provide control control provide access and
diagnostics traction brake egress
...
communication services
IEC 61375-2-3 TCN communication profile
IP based communication
process data message data
IEC 61375-2-5 Ethernet train backbone

IEC
Figure 1 – IEC TS 61375-2-4 as a link between the functions and the applications
As illustrated in Figure 1 the purpose of this part of IEC 61375 is to create a general model
that describes in a functional way the remote control of TCMS functions like “provide access
and egress”. This document makes direct reference to IEC 61375-2-3, which covers data
transmission on the Ethernet train backbone (ETB) and specifies the functions between the
consists concerned (e.g. locomotives, multiple units and driving trailers) including the rules to
set up the necessary data telegrams for transmission and process.
This document specifies the application profiles covering the train functions to:
a) provide access and egress;
b) control traction;
c) control brake;
d) provide diagnostics.
NOTE Functions b) to d) will be covered in a future revision of this document.
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 61375-1, Electronic railway equipment – Train communication network (TCN) – Part 1:
General architecture
IEC 61375-2-1, Electronic railway equipment – Train communication network (TCN) –
Part 2-1: Wire Train Bus (WTB)
IEC 61375-2-3, Electronic railway equipment – Train communication network (TCN) –
Part 2-3: TCN communication profile
3 Terms, definitions, abbreviated terms, acronyms and conventions
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 61375-1 and the
following 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
all doors of consist CLOSED
each single door of the consist is closed
Note 1 to entry: This state is side selective.
3.1.2
all doors of consist LOCKED
each single door of the consist is locked
Note 1 to entry: This state is side selective.
3.1.3
all doors of train CLOSED
all doors of each consist are closed
Note 1 to entry: This state is side selective.
3.1.4
all doors of train LOCKED
all doors of each consist are locked
Note 1 to entry: This state is side selective.
3.1.5
application profile
defined standardized set of services or functions offered to the application processes for
information exchange with specified data formats and data processing
3.1.6
CLOSE
action to juxtapose the door to its frame, to obstruct an entrance or opening
3.1.7
consist FAILURE
the consist is defined in failure state when the consist DCU control function or communication
is in failure
Note 1 to entry: Failure detection may be realized by self-diagnostic of the consist DCU or by function supervision
of consist DCU by the train DCU (e.g. process data sink time supervision).

– 12 – IEC TS 61375-2-4:2017 © IEC 2017
3.1.8
door ATTENDED
single door which remains active and open after the crew manipulator associated with it (e.g.
square key) has remotely commanded all the other doors of the train to close
3.1.9
door CLOSED
the door is defined closed when the door is adjacent to its frame and the mechanical locking
device is not in effect, making possible the mechanical opening of the door itself
Note 1 to entry: In this condition it is possible to move the door electrically or pneumatically.
3.1.10
door OUT OF ORDER
when at least one of the following conditions applies:
a) the link to the remote control is failing;
b) the door cannot be controlled locally
3.1.11
door ISOLATED
when it is closed and mechanically locked by means of the appropriate mechanical closure
device
Note 1 to entry: In this condition the door is permanently closed and locked and it cannot be moved in any way.
Note 2 to entry: In this condition the internal emergency handle and the outside one have no effect on the
opening of the door.
3.1.12
ISOLATE door
to close and mechanically lock the door and leave the door unable to execute any operation
command
Note 1 to entry: ISOLATE door uses mechanical methods in case of door malfunction. For example the door
isolation device is located on the door leaf, it is accessible from inside and /or outside via a square (or triangular)
key lock.
3.1.13
door LOCKED
the door is defined locked when the physical door is adjacent to its frame and the mechanical
locking device is in effect, making it impossible to open the door mechanically
Note 1 to entry: In this condition it is impossible to move the door physically.
3.1.14
door OPENED
the door is defined as opened when it is not adjacent to its frame and the entrance is not
blocked
Note 1 to entry: In this condition it is ready to accept a closing command.
3.1.15
driving trailer
vehicle with a driving cab at least at one end of the vehicle from which the traction and
braking functions of a train can be controlled
3.1.16
functional address
unique identification for a function

3.1.17
leading vehicle
vehicle, which is elected by a communication service of IEC 61375-2-3 and which controls the
movements of the train
3.1.18
locomotive
motor vehicle, not forming part of a train-unit and not carrying a payload, intended to move
other vehicles
[SOURCE: IEC 60050-811:2017, 811-02-06]
3.1.19
OPEN
action to move the physical door and create an entrance
3.1.20
passenger coach
passenger carrying vehicle without its own propulsion system
3.1.21
shoegear
train equipment to transfer electric current from the third rail
Note 1 to entry: It is usually mounted on bogies.
3.1.22
traction unit
vehicle with its own power equipment
3.1.23
vehicle
single item of rolling stock
Note 1 to entry: Examples of a single item of rolling stock include a locomotive, a coach and a wagon.
[SOURCE: IEC 60050-811:2017, 811-02-02]
3.2 Abbreviated terms and acronyms
ASC Automatic Speed Control
ASN.1 Abstract Syntax Notation 1
DAC Driver Activity Control
DB Deutsche Bahn (German Railways)
DCU Door Control Unit
DDU Driver Display Unit
DMU Diesel Multiple Unit
ED End Device
EMU Electric Multiple Unit
ENUM Enumeration
ETB Ethernet Train Backbone
ETCS European Train Control System
FI Function Interface
HMI Human Machine Interface
– 14 – IEC TS 61375-2-4:2017 © IEC 2017
HV High Voltage
HVAC Heating Ventilation and Air Conditioning
ID Identification
IP Internet Protocol
LV Low Voltage
MD Message Data
OSI Open System Interconnection
NOTE A universal communication model is defined in ISO/IEC 7498.
PD Process Data
PDU Protocol Data Unit
SNCF Société Nationale des Chemins de fer Français (French National Railways)
TBN Train Backbone Node
TCMS Train Control and Monitoring System
TCN Train Communication Network
TRDP Train Real time Data Protocol
TTDB Train Topology Data Base
UDP User Datagram Protocol
UIC Union Internationale des Chemins de Fer (International Union of Railways)
UML Unified Modelling Language
WC Water Closet
WSP Wheel Slide Protection
3.3 Conventions
3.3.1 Base of numeric values
This document uses a decimal representation for all numeric values unless otherwise noted.
Analog and fractional values include a comma.
EXAMPLE The voltage is 20,0 V.
Binary and hexadecimal values are represented using the ASN.1 (ISO/IEC 8824) convention.
EXAMPLE Decimal 20 coded on 8 bits = ‘0001 0100’B = ‘14’H.
3.3.2 Naming conventions
Keywords are written with a capital letter at the beginning.
If the keyword name is composed of multiple words, the different words are united with a
space and each word begins with a capital letter.
EXAMPLES “Train Backbone”, “Consist”, “Consist Network”.
Parameters are written with a capital letter at the beginning.
If the parameter name is composed of different words, the different parts of the name are
united without a space and each word begins with a capital letter.
EXAMPLE “NumberOfConsists“.
3.3.3 State diagram conventions
State diagrams are according to the notation of UML state machines.
3.3.4 Elementary data types
Elementary data types are used as defined in IEC 61375-2-1.
3.3.5 Derived data types
Derived data types consist of elementary data types, like for instance enumerations and
structures. Derived data types are implementation dependent; they are mainly user- or
manufacturer specific data types.
The enumerated data type declarations (ENUM) constrain the value of any data element of
that type to one of the values given.
4 Distributed train applications
4.1 General
The technology of the various traction units within the various railway operators can be very
different, considering, for example, the setting up of the traction power (contact breakers,
switch gear, converters) and its control (relay logic, analogue and digital electronic
equipment, microprocessors). A similar situation exists e.g. for doors providing external
access to the train for the passengers.
4.2 Function interface for remote control
Because of the existing technical differences, there are also large differences in the input and
output signals of the control equipment. Therefore it is not possible, in most cases, to use the
signals transmitted over the train backbone to directly control the equipment or to obtain
these signals directly from the control equipment. Consequently the remote function control
process needs to communicate via a standardized function interface, which ensures the
access to the remote door function process
Figure 2 shows as an example a common situation, when operating a train: One of the train’s
driver cabs on either end is the activated cab in the leading vehicle. In this cab the train driver
is controlling the train’s movement by actuating e.g. the traction lever. The command,
generated by moving the traction lever on the driver’s desk, sampled, and received by one
traction function (called function control) and propagated throughout the train via the train
backbone to all other traction functions via the comm proxy controlling locally the specific
traction subsystems. These processes, which are controlling the traction subsystems in each
consist or vehicle are called function process in Figure 2.

– 16 – IEC TS 61375-2-4:2017 © IEC 2017
driver
function
function
(led operation)
(leading operation)
interface
interface
function function
control control
cab
cab
(operation)
comm comm
proxy proxy
train backbone
communication
function communication communication function
process interface interface process
7 6 5 4 3 2 1 1 2 3 4 3 2 1
ETB
> > > >
4 3 2 1
consist network consist network consist network consist network

IEC
Figure 2 – Remote control of a process via the function interface
In Figure 2 the scenario is shown for the example of two driving cabs at each end of the train,
one cab in leading operation and the other cab in unattended and led operation. For this
remote control of functions, a set of signals, a so-called function interface, defines the
necessary set of data for a function to fulfil its characteristic action in the intended manner.
The way to transmit this set of signals via the ETB is defined as the communication interface
for the train backbone communication defined in IEC 61375-2-3. These transmitted signals
need to be translated in each consist in order to work with the actual control equipment of the
related subsystems. Figure 2 shows this process, whereas the train backbone communication
is the synonym for the data connections via the train backbone and the individual consist
networks.
Like the presented remote traction control function in Figure 2 above, there are additional
remote functions in a train, e.g. controlling doors, HVAC, exterior lighting, brakes. Thus a
communication link is established between the application function processes according to
rules laid out in this document.
4.3 General application architecture
The network architecture according to IEC 61375-1 defines the framework and constraints for
distributed applications in a train. Figure 3 illustrates this architecture with a generic
application.
train backbone
function function function function
TBN TBN TBN
leader follower follower follower
consist network consist network consist network
function function function function function function
device device device device device device

IEC
Figure 3 – Architecture of a distributed application
A train is composed by consists. Each consist contains a consist network, which is connected
via a train backbone node (TBN) to the train backbone, which provides the communication

infrastructure for the train wide communication. Train backbone, consist network, TBN are the
basic components of the train communication network (TCN) according to IEC 61375 series.
The generic function is composed of:
a) a function leader which is responsible to control the function by stimulation of the function
followers (commands) and to receive the reactions from the function followers (status);
b) one or more function follower(s), at most one per consist network, which is responsible to
receive the commands from the function leader and to stimulate the function devices. The
received reactions from the function devices are cumulated by the function follower and
provided as function status of the consist to the function leader;
c) one or more function device(s), which are receiving the commands from the function
follower, execute the function operations and report the results to the function follower.
These parts of the application are distributed over the consists of the train. Different parts of
the application in different consists can communicate only via the TCN.
For interoperability of consists only the communication between function leader and function
follower is relevant. The interaction between function follower and function device is provided
as information for better understanding of the behaviour of the application.
This technical specification does not require the consist network as communication
infrastructure between function follower and function device. There may be any connection,
e.g. wired by simple electric lines.
4.4 Architecture model
Figure 4 shows a graphical representation of the distributed application, which is used to
model the communication flow (see 4.6).
application interface application diagnostic interface
(mandatory control/status) (conditional)
function leader
1.*
func
...