Safety assurance research on LED railway signal equipment in a network communication environment

Railway signaling systems are being upgraded from electric interlocking to computer interlocking gradually. The requirements of Reliability, Availability, Maintainability and Safety (RAMS) become stricter and stricter. In this paper, we propose LED signal equipment with new assurance technologies on principles of standard IEC 61508:2000, and EN 50126:2002, in an environment of using network communication for control information transmission. The newly-designed LED railway signal equipment, containing logical system and using integration technology during the design, has high RAMS. The test conducted on the prototype proved higher safety of the signal equipment, compared with the traditional ones.