Remote Fault Diagnosis Research On PLC Controlling Network

With the automatization, complication and continuity of industrial controlling equipments, we must ensure that the equipments are running normally, reliably and effectively, and also ensure that the people at the spot are in safety. With the fierceness of competition between the enterprises in the market and the speedy development of computer network and communication technology—especially the development of Internet and Information-highway, technology of Remote Fault Diagnosis was emerged and has been widely put into use. Nowadays, PLC has largely been used at the industrial spot, consequently PLC controlling network has been an important diagnostic object of RFDS (Remote Fault Diagnosis System).In the background of PLC controlling network of Tire Tread Extruding Line and according to system structure and performance of the line, this paper studies the types, range, and causes of the line. On the basis of studying the theory of traditional and modern fault diagnosis, we established the fault diagnosis model of the system by using FTA (Fault Tree Analysis). We also built the Supervision&Controlling Station with fault diagnosis function at the spot by using the strong diagnosis function and ability of S7-300 PLC and IPC, the high speed, bidirectional digital communication of PROFIBUS and self-diagnosis of intelligent driver. Subsequently, we reliazed IFDS (Intelligence Fault Diagnosis System) of the PLC controlling network by using Expert System with FTA, and completed the software and hardware design of IFDS—including the Knowledgebase, Rulebase, Database and etc. Finally, we realized the cooperative remote diagnosis mechanism between the Enterprise Fault Diagnosis Center, Remote Fault Diagnosis Center and Diagonsis Expert in the Internet by using Web technique, distributed technique and structure pattern of B/S (Browser/Server) with C/S (Client/Server), so the plenty resource of technology, intelligence, and diagnosis in the Internet could be used.At present this Fault Diagnosis System has been put into use, it meets the expected design demands very well, highly improves the reliability and safety of the spot industrial equipments, and enhances production efficiency and product quality, thus we have been achieving notably social and economic benefit.