Train Communication Network

At the Train Communication Network (TCN ) is a system of two fieldbuses, which has a hierarchical structure. It is designed for railway vehicles, in order to replace the analogue remote control and to detect the operating states of the individual vehicles.

The TCN should not be confused with today's commonly employed timeplexed shuttle train for locomotives (ZDS or CFB). While a time-division push-pull train, very few can exchange data (up to 12 bytes ), it can be transferred with TCN a much larger amount of data. TCN is used to transfer different types of data, such process signals can be transmitted up to 32 bytes in size at time intervals from 1 ms. Longer messages up to 4 GB ( a theoretical limit, normally 10 bytes - approx 10 Kbytes ) can be treated as non - real-time data also transferred.

Genesis

In railway vehicles, more and more computer-controlled components were used. These are among others the heating with air conditioning, the auxiliary converter and the closed toilet facilities. These were not initially linked together so that disturbances were mostly read by the train crew only to control lights. Also in the shop the exact cause of the fault was mostly read only on the control itself, but what equipment boxes had to be opened. Therefore, the desire for a large vehicle diagnostic system has been expressed. This was the vehicle bus. As a logical step may then be regarded as the extension of this diagnostic system, so that from a central point on a fault -screen information to all other vehicles can be called. Also, the long- desired face-selective door control and monitoring is made possible by the train bus. Also, the multiple control of vehicles is handled by the train bus.

Construction

There is a so-called vehicle bus MVB ( Multifunction Vehicle Bus) and a train bus WTB ( Wire Train Bus). TCN is almost exclusively used in railway vehicles, vehicle bus is therefore to understand festgekuppelter vehicles as a field inside a vehicle or a group, on the other hand connects train bus as a fieldbus, the different vehicles and includes an entire train. For TCN two different data types have been defined: process data ( PD) and Message Data (MD). PD is a short -time-critical data (up to 32 bytes and 128 bytes on MVB WTB ), which are sent at regular intervals. Interval length is between 1 ms and 1024 ms. MD, longer messages that do not cyclical, but are transmitted on demand. You may be segmented on the bus and always acknowledged. They are similar in principle with TCP. TCN has been standardized by the IEC, IEC 61375.

Application

The TCN is used in many of today's locomotives. Usually the 18-pin UIC line is used for the train bus. This applies, however, only to vehicles that do not run in a fixed train set. In trainsets usually special cables are used.

The Intercity Express ICE T, ICE TD and ICE 3 of the Deutsche Bahn are multiple units with TCN ( ICE 1 does not work based on two buses TCN, but a common bus ).

At the Swiss Federal Railways, this principle of TCN was first used on a large scale in the 1997 acquired commuter trains with the Re 460, as well as the associated IC2000 and EW IV-commuter trains.

In the Austrian Federal Railways ( ÖBB) the train bus comes accordance with UIC Leaflet 556 in almost all modern locomotive series (1014, 1016, 1116, 1216, 1142, 1144, 2016, 2070 ), as well as all the push pull control car ( 80-33, 80-73, RailJet ) apply. All of these vehicles are compatible therewith also with respect to the remote controller. The transport railcars of "talent" family ( 4023, 4024, 4124 ) use the train bus.