차상신호장치와 MMI간 버스형 네트워크 통신프로토콜 설계

Protocol Design for Bus Network Communication between Onboard Signalling System and MMI

In this paper a protocol design for bus network communication between onboard signalling system and MMI(Man Machine Interface) will be presented and illustrated. Recently, many onboard signailling systems adopt hot standby for safety reasons. Hot standby is a method of redundancy in which the primary and secondary systems run simultaneously. It is convenient to use bus network(bus topology) in a hot standby system for communication between onboard signalling system and MMI. Because bus network is the simplest way to connect multiple clients such as onboard signalling system, MMI and etc. However, there are many problems when two clients want to transmit at the same time on the same bus. A effective protocol is necessary to solve that problems. We will describes protocol design which is useful when onboard signalling systems and MMIs are connected via RS485(Bus Network).