The Design And Realization Of The Field Acquisition Equipment Of Alert Information On Railway Signal

The increase in the flow rate of train on the railway has brought a stronger transport capacity, but in the meantime it brings a greater challenge to the maintenance work. In order to protect the worker on the railway from injury, a project of precaution system has been set up. This study focus on the field signal-acquisition equipment of the precaution system- safety equipment.The precaution system detect lots of switch quantity signal on the railway field to offering the message that guide workers to avoid rain or to do work. This signals have been conducted to signal control station. Safety equipment was installed in the station for data acquisition and storage to facilitate monitoring terminal accessing.Signal acquisition: in order to adapt to the complex environment, this study presents a scheme can applied to multi-channel acquisition, compatible with AC/DC with stronger anti-interference ability. By this process of half-wave rectification, voltage limiting, anti- shake resisting interference, photoelectric isolation, inverting shaping, and these signals was in line with the conditions to MCU. In this scheme, the STM32F107VCT6 of STMicroelectronics company was been taken for circuit design. These MCU embedded a CAN controller and Ethernet MAC controller, with simplifying the CAN and Ethernet communication peripheral circuits.Data communication: with the requirement of project, this study presents an application protocol scheme of the CAN data and Ethernet data. Safety equipment collect data by CAN bus network: inner CAN is responsible for internal data exchange in the equipment. External CAN preside over Data exchange between equipment, Convenience to expanding abilities to capture possible Ethernet communication adopt Light Weight Internet Protocol(LWIP) and the safety equipment work in TCP-Sever mode for monitoring terminal accessing.Safety equipment have been put into use, with data acquisition of real-time and accurate. The equipment is an indispensable part of precaution system, with the advantages of being stable, reliable, small size, flexible use and strong expansibility,therefore it has an optimal value of application.