Train Communication Network

This article or paragraph presents the situation in Germany . Help us to describe the situation in other countries.

The Train Communication Network (TCN) is a system of two field buses that is structured hierarchically. It was developed for railway vehicles to replace the analog remote control and to be able to record the operating status of the individual vehicles.

The TCN must not be confused with the time-division multiplex push-pull train control commonly used in Germany for locomotives (ZDS or ZWS). While a time-division multiplex push-pull train control can only exchange very little data (up to 12 bytes), a significantly larger amount of data can be transmitted with TCN. TCN is used to transmit various types of data, so process signals up to 32 bytes in size can be transmitted in time intervals from 1 ms. Longer messages up to 4 GByte (a theoretical limit, 10 bytes are normal - approx. 10 kByte) can also be transmitted as non-real-time data.

History of origin

More and more computer-controlled components were used in railway vehicles. These include the heating with air conditioning, the on-board power converter and the closed toilet facilities. Initially, these were not linked to one another, so that the train crew could only read malfunctions from control lamps. In the workshop, too, the exact cause of the malfunction could usually only be read off on the control itself, for which the apparatus boxes had to be opened. For this reason, the desire for a vehicle-wide diagnostic system was expressed. The vehicle bus emerged from this. The expansion of this diagnostic system can then be viewed as a logical step so that information on all other vehicles can be called up from a central point on a malfunction screen. The long-desired side-selective door control and monitoring is also made possible by the train bus. The multiple control of vehicles is also handled via the train bus.

construction

Structure of the TCN

The TCN has a two-stage structure and consists of a WTB ( Wire Train Bus ) and an MVB ( Multifunction Vehicle Bus ) vehicle . The WTB is a fieldbus that is used for communication between the individual vehicles within an entire train composition . The MVB is used for internal communication within a vehicle or a group of permanently coupled vehicles. Accordingly, the WTB without repeater is limited to a maximum of 32 nodes (gateways) and a maximum length of 860 meters (22 UIC cars ). Several hundred devices can be connected to the MVB, but its length is limited to 200 meters. Both levels are connected by nodes in the individual vehicles.

Two different types of data have been defined for TCN: process data (PD) and message data (MD). PD are short, time-critical data (up to 32 bytes on MVB and 128 bytes on WTB) that are sent at regular intervals . The interval length is between 1 ms and 1024 ms. MD are longer messages that are not transmitted cyclically, but on request. If necessary, they are segmented on the bus and always acknowledged. In principle, they are comparable to TCP .

application

The TCN is used in many of today's locomotives. The 18-pin UIC cable is usually used for the train bus . However, this only applies to vehicles that do not run in a fixed train composition. Special lines are usually used in multiple units.

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

At the Swiss Federal Railways , this TCN principle was used for the first time on a larger scale in the commuter trains with the Re 460 and the associated IC2000 and EW-IV pendulum trains that were acquired from 1997 .

With the Austrian Federal Railways (ÖBB) , the train bus comes in accordance with UIC leaflet 556 in almost all modern locomotive series ( 1014 , 1016 , 1116 , 1216 , 1142 , 1144 , 2016 , 2070 ), as well as all push-pull control cars (80-33, 80-73 , RailJet ) are used. All of these vehicles are therefore compatible with regard to remote control. The local railcars of the " Talent " family (4023, 4024, 4124) also use the train bus.

literature

• IEC 61375-1: 2012 Electronic railway equipment - Train communication network (TCN) - Part 1: General architecture

Web links

• Hubert Kirrmann (ABB Corporate Research), Pierre A. Zuber (DaimlerChrysler Rail Systems): The IEC / IEEE Train Communication Network . (PDF) In: IEEE Micro . March-April 2001, August, pp. 81-92. 0272-1732 / 01.
• The IEC / IEEE / UIC Train Communication Network for time-critical and safe on-board communication ( en , powerpoint; 3.7 MB) Bombardier Transportation. June 10, 2002. Retrieved October 7, 2011.

Individual evidence

1. ↑ Hubert Kirrmann: Train Communication Network IEC 61375-4 Wire Train Bus. (Powerpoint; 1.0 MB) (No longer available online.) École Polytechnique Fédérale de Lausanne (EPFL), January 20, 1999, archived from the original on June 16, 2011 ; accessed on October 7, 2011 (English). Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  
2. ^ Bernhard Tellenbach: From the passenger information system to the infotainment system. 2005, accessed September 24, 2019 .