2002 June 10, APTA, Baltimore, Zuber-Kirrmann 1 The IEC / UIC / IEEE Train Communication Network for time-critical and safe on-board communication Pierre.

2002 June 10, APTA, Baltimore, Zuber-Kirrmann 1

The IEC / UIC / IEEE Train Communication Network

for time-critical and safe on-board communication

Pierre Zuber, Bombardier Transportation, Pittsburgh, USA

Hubert Kirrmann, ABB Corporate Research, Baden, Switzerland

• What is the Train Communication Network ?• Wire Train Bus• Multifunction Vehicle Bus• Real-Time and Deterministic data transfer• Message Services• Available and Safe Architecture• Standardization of Vehicle data• ROSIN -TrainCom - ERRI projects • Conclusion


The IEC Train Communication Network

international IEC and IEEE standard for data communication aboard rail vehicles.

Vehicle Bus

Train Bus

Vehicle Bus Vehicle Bus

manufacturers:

Bombardier - ADtranz (CH, DE, SE)

ANSALDO (IT)

CAF (ES)

Firema, Ercole Marelli Trazione (IT)

Mitsubishi (JP)

Siemens (GB, DE)

Toshiba (JP)

Westinghouse Signals (GB)

railways operators:

Chinese RailwaysDB (Germany)FS (Italy)JRRI (Japan)NS (Netherlands)RATP (France)SNCF (France)

UIC (Union Internationale des Chemins de Fer) PKN (Poland)

developped by IEC TC9 (Electric Traction Equipment) with the collaboration of:

UITP (Union Internationale des Transports Publics)

Alstom (FR, GB, BE)


Objectives of the TCN

Define interfaces between programmable equipment's, with the aim of achieving plug-compatibility:

1) between vehicles

2) between equipment aboard a vehicle:


TCN’s network architecture

The Train Communication Network consists of:

• a Train Bus which connects the vehicles (Interface 1) and of

• a Vehicle Bus which connects the equipments within a vehicle (Interface 2).

vehicle bus devices

train bus

vehicle bus

node node node

vehicle bus vehicle bus


Wire Train Bus (WTB)

thousand of vehicles in daily operationreferences

1 Mbit/s over shielded, twisted wiresdata rate

32 (some vehicles may have more than one node)number of nodes

860 m, 22 vehicles (including passive, retrofit vehicles)covered distance

assigns to each node its sequential address and orientation

ERRI (European Rail Research Institute, Utrecht, NL)conformance

inauguration

standard communication interface between vehicles

25 ms cycle timeresponse time

open trains with variable composition such as UIC trainsmain application

nodenodenode


WTB traffic

Vehicles of different types communicate over the train bus for the purpose of:

telecontrol traction control: vehicle control:

diagnostics

passenger comfortseat reservation

1)

2)

3)

lights, doors, heating, tilting, ...remote, multiple traction,...

next station, delays, connections.

coaches for destination Xcoaches for destination Ylocomotive driving coach

driver's cabtrain attendantdiagnostic computer

equipment failures, maintenance information


WTB wiring

UIC specified a data cable ( 18 pole) compatible with the 13-pole UIC connector

Since there are normally two jumpers, wiring is by nature redundant

Fritting (voltage pulses) is used to overcome oxidation of contacts

UIC data cable

Line B

Line A

jumper

Line A

vehicle vehicleWTB cable

Line B

WT

B node

11

top view

2classic

UIC lines

jumper

classic

UIC lines

redundant nodes

2

WT

B n

ode

WT

B n

ode

Wiring over shielded twisted pairs, jumpers or automatic couplers between vehicles.


MVB paves the way to interchangeability of equipment and simplified maintenance.

MVB is important for:

• small equipment manufacturers(reduced bus diversity)

• vehicle assemblers(wider choice of suppliers, commissioning)

• railways operators(less maintenance and spare parts)

All MVB devices are interoperable: there exist no incompatible options

MVB - the standard vehicle bus

Why standardize the vehicle bus ?


Multifunction Vehicle Bus (MVB)

data rate

delay

media

number of stations

tens of thousand of vehicles in servicestatusup to 4095 simple sensors/actuators

1,5 Mbit/s

shortest period 1 ms

shielded twisted pairs and optical fibers

up to 255 programmable stations

cockpitpower line

diagnostics

radio

Train Bus

motor controlpower electronicsbrakes track signals

Multifunction Vehicle Bus

“standard interface for plug-compatibility between equipment on-board vehicles”

clock synchronization within a few microsecondtime distribution


Example: Vehicle Control Units

MVB


MVB wiring

The MVB can span several vehicles:

The number of devices under this configuration amounts to 4095.

Train Bus

devices

node

devices with short distance bus

repeaterMVB

The MVB can serve as a train bus in trains with fixed configuration, up to a

distance of 200 m (EMD medium) or 2000 m (OGF medium).


TCN combinations

MVBMVB

MVB MVB

MVB

860 m (without repeater)WTB(standard)

Open train

0 vehicle bus 2 vehicle busses(standard & not)

1 vehicle bus(standard MVB)

MVB or other(not standard)

Closed train

1 vehicle bus 0 vehicle bus

WTB(standard)

Connected train sets

1 vehicle bus200 m (without repeater)

200 m without repeater

not standard vehicle bus

0 node(conduction vehicle)


TCN protocols

both the train and the vehicle bus use the same protocols

- deterministic (periodic) transmission of time-critical process variables

- reliable, demand-driven messages in • point-to-point and • multicast

Net

wor

k M

anag

emen

t

Multifunction Vehicle Bus

Variables

Network

Session

Transport

Presentation

ApplicationInterface

Messages

ApplicationInterface

otherbus

Wire Train Bus

common


Train and Vehicle Bus Operation

State of the PlantResponse in 1..200 ms

Spurious data losses will be compensated at the next cycle

event

Sporadic dataSporadic Datatime

On-Demand Transmission

Events of the PlantResponse at human speed: > 0.5 s

• Initialization, calibration

Flow control & error recovery protocol for catching all events

• Diagnostics, event recorder

Basic Period Basic Period

State Variable Messages

... commands, position, speed

Periodic Transmission

Periodic Data

determinism is the condition for safe and available operation


WTB and MVB: Integrity and availability principles

Both WTB and MVB comply with IEC 60870-5-1 integrity (HD = 4 on TWP, 8 on fiber)

A study at Carnegie Mellon University fully confirmed TCN’s integrity.

The TCN architecture allows to build a network without a single point of failure.

Duplicated physical layer is the default, single line is also possible.


Further standardization

TCN laid the ground for standardization of data interchange not only betweenvehicles but also between vehicle and ground (signaling) and radio links


UIC (International Railways Union) train data

Electrical and data link interoperability is necessary, but not sufficient for interoperability

UIC556 cross-identification, process and message data formats

UIC556vehicle data

Once vehicles are able to communicate, they exchange their identification and capabilities:

e.g. “I am a traction vehicle, my weight is 50 T, my length 23 m,….“I support diagnostic data, passenger information, multiple traction,…”

To ensure “plug-and-roll”, UIC defined all traffic on the WTB:

The “mapping server” in each executes the protocol for cross-identification of the vehicles

UIC557diagnostic data

UIC647traction data

UIC176passenger info

IEC 61375 / IEEE 1473 train and vehicle bus, process and message protocols

operator-specific


ETCS - Eurocab

MVB is used as the vital on-board bus for Eurocab (European Train Control System).To this purpose, safety protocols on top of TCN have been developed

MachineInterface

Man-MVB

Interface

Brake

Interface

Track

Interface(s)

Balise Speed andDistance

MeasurementTraction

DataLoggerRadio

Clock

Computer

Vital


Safe Architecture

Safety protocols were developed for 2/3, 1/2 or coded processors, provide time-stamping, authentication and value check over cyclic services.

coded monoprocessor

F Fc

triple modularredundancy

F1

simplex sensor/actor duplicated sensor/actor triplicated sensor/actor

diverse programming

dumb devices(no application programming)

intelligentdevices

(application programs) F1 F2c

A B A B

and/or

and/orand/or

F2

and/or

untrusted bus

Single channel, dual redundant and triple redundant devices can interoperate.

Vital and non-vital devices of different origin can interoperate over the same MVB.

A CB

F F F


ROSIN - European Program

Device: Door controlMade by: WestinghouseYear: 1995Revision: 1998 May 19Parameters: position, status, indication, ......Maintenance messages:....1996 Jun 25 10:43 23" low air pressure1996 Jun 26 10:55 09" emergency open1996 Jun 26 11:01 17" manual reclose....

air conditioningpowerlight

doors

Universal Maintenance Tool

It defined data interchange for passenger vehicles, freight trains, radio links,…

This multi-year (and multi-million $) project of European Union based on TCN.

brakes

This work supported the parallel standardization in UIC 556 / 557


RoMain - Rosin Maintenance

Remote web access over radio was demonstrated on the Eusko train

remote RoMain clients

ROSIN server

ADtranzserver

Ansaldoserver

NetscapeInternet Explorer

Secure TCP/IP Network

servers

operators manufacturers

ERRI

Bus A node Bus BBus Anode

RoGate

radio proxy


IEEE standardisation

The IEEE Rail Transit Vehicle Interface Standard Committee influenced TCN

WG1 adopted TCN as IEEE 1473 Type T and defined interoperation with foreign components.

WG9 is working on information interchange standards and collaborates with UIC

LVB

LSB

WTB

other bus

MVB

MLgateway

MVBstation

MVBstation

MVBAdministrator

WTB node

Operation of mixed systems in the USA showed the importance of strict definition of interchanged data and how money spared by off-the-shelf is wasted in costly adaptations


TrainCom

The successful ROSIN project was followed by another European project: TrainCom.

TrainCom considers in particular:

- locomotive interoperability (multiple traction) in collaboration with UIC 647

- GSM radio links

MORANEMORANE

TrainComTrainCom

ERTMS kernelERTMS kernel

TTRAINRAIN

CCOMOM


Acknowledgements

To all engineers of ABB, Adtranz, AEG, Alstom, Duagon, ERRI, Firema, I.PRO.M, Siemens,…

To the railways people in UIC which dedicated years of work in the standard groups


Conclusion

TCN is a suite of communication and application protocols tailored for therailways, not just a field bus.

•

TCN imposed itself as the standard communication network in railways•

TCN (MVB) has been adopted in electrical substations and printing machinescapitalizing on the work done by the railways community.

•

•

• Work on TCN is not finished - UIC, TrainCom and IEEE RTVISC WG9 are at work…

UIC did a great job in the definition of the application data, the industry couldreadily support this effort in the ROSIN and TrainCom projects. IEEE RTVISCWG9 has adopted UIC 556 as the basis for IEEE 1473-T train busdata communication.

TCN is an open technology - there are no royalties, patents or copyrights.Anyone can build a TCN according to specs - chips are available.

TCN source code is available on www.traincom.org

•


Reserve slides


Why not Ethernet instead of WTB ?

Ethernet uses a star topography (point-to-point to a hub). A train has a linear topography.

Ethernet would need special hubs which recognizes right and left in each vehicle.

Hubs would be a single point of failure, a battery failure in a vehicle would stop the bus.

Hubs cannot be used for freight vehicles (no battery in the vehicles).

In spite of providing 100 times more speed then WTB, Ethernet real-time response is not better, because of overhead associated with transmitting numerous, small data items.

Ethernet is just a level 2 (up to data link) specification mutual identification of vehicles are yet to be developed.

IP and UDP are too slow for time-critical data (traction data), reconfiguration in case of failure takes several minutes.

there is no alternative to WTB as a train bus


Process Data transmission by source-addressed broadcast

The device which sources that variable responds with a slave frame containing the value, all devices subscribed as sink receive that frame.

The bus master broadcasts the identifier of a variable to be transmitted: Phase1:

Phase 2:

devices(slaves)

bus

subscribed subscribed

variable value

bus

busmaster devices

(slaves)source sink sink

subscribed devices

sink

subscribed device

subscribed device

variable identifier

busmaster source sink sink

subscribed devices

sink

devicedevice


The concept of real-time, distributed database

cyclic algorithms

cyclic algorithms

cyclic algorithms

cyclic algorithms

port address

application1

TrafficStores

Ports Ports Ports

application2

application4

sourceport

sinkport

port data

bus controller

bus controller

bus controller

sinkport

cyclic poll

bus controller

busmaster

application3

bus controller

bus

PeriodicList

Ports

Bus and applications interface through a shared memory, the traffic store.

Bus traffic and application cycles are asynchronous to each other.

Cyclic bus traffic blends with IEC 61331-style of programming


Hard Real-Time and Soft Real-Time

response time

probability probability

unbounded !

1 element 2 elements in series

still bounded !

t2t4

t2+t4t2t1

t1+t3

t1

t3hard(cyclic)

t1+t3

t1

t3

Determinism is not a bus, but a system issue.

response time

probability

unbounded !

soft(event-driven)

t2t1

e.g. vehicle bus and train buse.g. vehicle bus

bounded !


number of devices: 37 ( including 2 bus administrators)

37 of 16 bits

16 ms 32 ms 64 ms 128 256

49 frames of 256 bits

30 frames of 128 bits

1024

65 frames of 64 bits18 of 32

period

% periodic time

occupancy is proportional to surface

total = 92%

Already today, long frames dominate

Locomotive 465 Frame Occupancy

2002 June 10, APTA, Baltimore, Zuber-Kirrmann 1 The IEC / UIC / IEEE Train Communication Network for time-critical and safe on-board communication Pierre.

Documents

standard vehicle bus

vehicle bus standard

vehicle interface

wire train bus wtb

train bus devices node

mvb devices

vehicles interface

standard closed train