Rail Signaling Systems
ITCS (Intermodal Transport Control System) stands for computer-based control of information and communication between the train, the wayside equipment and the control center. As a part of this network, operation of signals, switches and interlocking blocks is controlled by signaling computers. Electronic subsystems are characterized by their extreme reliability regarding error-free operation according to safety levels SIL 1 to SIL 4. Redundancy architecture of the computer system or parts of it is required in combination with a safe operating system and a safe application. As this type of equipment needs certification by the national railways authorities, a minimum delivery of 10 years is mandatory.
In one application, 2oo3 systems are installed in railway stations in many European countries. The CompactPCI system houses three independent and identical 6U single-board computers with corresponding I/O cards and uses independent backplanes and power supplies. At least two of the three computers must yieldidentical results to guarantee the correct operation of the complete system. The Intel Celeron based CPU cards are equipped with XMC modules, thus supporting up to 12 Gigabit Ethernet channels. ANSI mezzanine standard M-Modules are used to provide the HDLC/SDLC functionality, and PC-MIP mezzanines are used to provide the TTL I/O.
A similar application features a single redundant Intel Pentium based solution implemented in 3U CompactPCI systems.
Another solution is also based on 3U CompactPCI and provides the vital control functions for automatic train operation. It communicates with the trains via inductive loop channels and other wayside equipment. Three sub racks form a 2oo3 system with external voting, housing a total of nine COTS-based F14 Intel Celeron CPU cards . Each sub rack features one main processor and two I/O processor cards. The CPU cards offer state-of-the-art PC interfaces at the front and connect specific functions to the rear, for example PPE interfaces, a CCOT terminal, or interprocessor communication via two LVDS reflective memory interfaces. The I/O computers offer additional discrete inputs, status lines, interrupt lines etc.
Rail signaling computers are typically specified for an operation temperature between 0°C to 60°C.