Design And Implementation Of Liquid Level Monitoring System Of Cables In Signals' Foundation Snake Tube In Railway Station

With the development of railway science and technology and speed-increases, the safety of railway traffic is more important. Whether the signals work reliably or not directly affect srailway safety and whether the cables in snake tube transfer data reliably or not plays a key role in the signals' normal work. When rain enters into the snake tube, cables are soaked in water long time and in winter the rain in snake tube will be frozen. All this can Influence the cables' lifespan and the railway safety. Therefore, design a water level of cables in signals' foundation snake tube monitoring system in railway station and it is meaningful to the signals' maintenance promptly.Researches and designs a water level of cables in signals' foundation snake tube monitoring system in railway station utilizing technology of sensors, CAN bus and computer. System uses sensors as front-end acquisition circuit to acquire humidity and water level in snake tube. And uses the high precision level sensor and complementary with humidity sensor to obtain a qualitative and quantitative water level. System adopts ATMEGA series microcontroller as lower computer, makes the humidity value and level value store in the memory after the A/D conversion with interrupt methods, then transfers processed data with the communication to the CAN bus. Using high-performance computer as a PC, creates a single document based on the PC program, completes system parameter setting, humidity and level displaying, the voice and image dual alarming as liquid level overrun, data storage and inquires, and other functions utilizing VC++ 6.0 software in Windows operating system platform.The operation of the system indicates that the system can realize lighter base snake tube cable for signal on-line monitoring in railway station, provides comprehensive and reliable cable's water status information for signal maintenance personnel, avoid the waste in staff and economy due to useless maintenance when water not overrun. The system gives the warning information of water level in cable timely if the water level is higher than the security level and meanwhile makes the signal maintenance personnel maintain the equipment promptly, so it is meaningful to the safety of railway traffic. The system has universality and expansibility to some certain extent. It can install the system in different stations and also can increase the monitoring nodes easily and provide some reference for further research to water level in signal's cable monitoring online system.