Design of Distributed Industrial Monitoring System Based on Virtual Token Ring

In the paper an intelligent distributed measurement and monitoring system for point machines in railway using power line carrier communication is designed. After simply describing the architecture of the system, the design of communication protocol based on virtual token ring is introduced. A logical token ring network is presented, and then data frame format, the principle of normal working, adding node to network and error processing are discussed in detail. The performance evaluation of token ring method and cyclic access method in terms of throughput and delay are given finally, which shows that token ring method performs better than cyclic access method. Self-maintenance, high efficiency, high fault tolerance and high real-time make sure the distributed monitoring system based on virtual token ring to be applied in many applications in industrial monitor field, which require distributed, long-distance and real-time data gathering.