Application Of Profibus In PLC

With the rapid development of information technology in modern society , automation system has taken great changes. Then the enterprise also established new information system. With the requirements of enterprise, which is automation, digitization, intelligentce, the fieldbus emerges as the times requirements and satisfies the demand of global industrial transformation. Amoy the fieldbus technologies, Profibus stands out from the crowd, and becomes the first choice of the enterprises. In the areas of fieldbus technology, Because of Profibus have the stable international standard EN50170 as guarantee , Profibus become the setters of international market, and become the only national standard of fieldbus in current China (GB/T 20540-2006).The PLC of SK who as the independent intellectual property rights in our country, has made rapid progress with its excellent technology during these years. Not only get the authentication of electromagnetic compatibility(emc),but also have the European's (ce) authentication, thus obtain the passport to enter the European market. At present, the mountain division in the market and PLC has international and old brand launched fierce competition, and has obtained some achievements. However, the support of the mountain secco PLC is more onefold, communication protocol still in most cases depend on free mouth agreement with other equipment, communications that this will greatly influence the applicability of the mountain division, thus PLC restrict its market share., In order to make the SK PLC success to access the system of Profibus, this text based on analyzing the principle and current situation of Profibus and PLC, and analyzing, screening various of design schemes, in the end it put forward a Profibus communication module design scheme which aims at the PLC of SK. This plan includes making use of microcontroller and special agreement chip VPC3+C to design the hardware and the software design which based on it .This test make the PLC of SK not to change the original agreement and structure which make the PLC as the slave station realize to communicate with the master station, and realize the PLC's seamless docking with Profibus. The design of this module will make the PLC prove the applicability and compatibility, thus it will prove the competitiveness of the market to a certain extent, and increase the occupation ratio of the market. Of course, this text only realize the communication function of Profibus-DP, the stability of communication and the problem which can appear through the communication don't research deeply, thus in order to make the communication module through the test of Profibus's product certification laboratories and become a qualified products,it need further exploration and experiment.In this paper, it will makes a deep research and positive exploration with the independent PLC which as the slave station of Profibus to insert the bus system. It also will help Other instrument equipment of the PLC to realize the communication of the Profibus.