The Research Of Distributed Monitoring System Based On Middleware Technology

With the rapid development of high-speed rail, people are very concern about train security. In order to ensure the safe operation of trains, it need to do many train track experiments, to achieve train real-time monitoring.Because of so many detection channel and the high sampling frequency, it will collect a large mount of data in a short period. It is a big problem to store or transmit the large amounts of data for the train monitoring system. The data the portable data terminal collected, on the one hand need to be stored,on the other hand need to be transmitted to PC to be process in time and analysis the train equipment health.; And in order to let the ground control center achieve the real-time remote monitoring, the data must be transmitted to the ground in time. For this perpose, the paper design an efficient data transmission system for train monitoring networkThe system mainly consists of the data collector, the PC,the manager, the ground server and the ground control center. The collector takes data, restores and sends it to the PC. The PC computes and sends the result to the manager. Manager uses GPRS module to send the result to the ground server. Then the ground server send it to the ground control center. If it is necessary, the ground control can request the original data of a collector.The communication of the system is based on ZeroMQ. ZeroMQ is simple,flexible, efficient and have so many advantages. The communication between the PC and manager, the communication between manager and the ground server, and the communication between the ground server and the ground control center is base on the ZeroMQ socket. The request from the ground control center to the PC, and the reply from the PC to the ground control center is based on advanced Request-Reply model. and uses ZMQ_XREQ——ZMQ_XREP to implement. The transceiver of original data and characteristic value data is based on Publish-Subscribe model, and uses ZMQ_PUB——ZMQ_SUB to implement In order to improve the efficiency of the system, use a single thread for each of the three data type. The communication between the threads is based on signal model, and uses ZMQ_PAIR——ZMQ_PAIR to implement.This paper has developed the software of the PC, the manager, the ground server and the ground control center.Firstly, the paper introduces the topis’s background, significance and development in china or other country, then research the communication models and message of ZeroMQ, and introduce the entire system structure in detail. Lastly, introduce the software implementation of the various modules of communication, and test the communication performance of ZeroMQ.