These railway traffic management electronics for fully automated underground systems are based on VMEbus components in double Eurocard form with M-Modules™ providing additional RS232 interfaces. They support both local and distributed network architectures and are part of a plant management system that acts as the interface between the supervisory system and all other subsystems. The core of the single-board computer is a PowerPC® MPC8245 equipped with dual Fast Ethernet and four COMs. Since the requirement was to have up to 25 serial interfaces implemented on the same CPU card, the three on-board M-Module™ slots are used to provide the additional COMs. With eight interfaces per M-Module™, a total of 28 serial lines per single-board computer is possible. Each RS232 channel has its own FIFOs for transmitting and receiving and its own timer to monitor data reception. A total of 36 control and data lines for the eight communication channels per M-Module™ are available at a space-saving 44-pin HD-Sub connector at the front side of the board. Handling of special characters can be programmed as needed. In some of the applications additional binary I/O is is provided by plugging a second 6U card with 128 optically isolated binary inputs/outputs into the VMEbus system.

These electronics are a part of a supervisory system which controls and monitors systems, subsystems and devices like building and supply systems (waste water pumps, water treatment facilities and pumps, locks), display systems, electrical trains and systems on the train, signal systems, lifts and escalators, fire monitoring and protection systems, electrical facilities, communication systems on the train (CCTV, radio etc.) or at the station and in the control center (radio, telephone etc.) and many more. These plant management systems are implemented worldwide, for example in Singapore, Hongkong, Venezuela, Chile, Taiwan, China, Marocco, Tunisia. Along the 20 kilometer route of the first application 40 CPU cards and more than 100 M-Modules™ are installed.