Research Of System Integration And Application Based On Proflbus-DP And Modbus

Because of its open, decentralized and fully interoperability features, Field-buscontrol system become the new developing direction in the field of industrial controlin the future. Since launched a PROFIBUS communication protocol in1989, to2007,the installation of the PROFIBUS nodes number in the world has already reached20million, has been widely recognized, the proportion of its market share has exceededtwenty percent, the nodes all over the world, has become the international field-busmarket leader.MODBUS is an open protocol standard, the message frame format issimple and easy to understand, make rapid application development users, MODBUScommon RS-232also supports industrial site, RS485communication interface, etc.Due to these advantages, making the MODBUS equipments are widely used in thefield, has become the indispensable field bus of industrial communication network.Because the MODBUS protocol is simple and practical, field device USES is theMODBUS interface, more as a Profibus-DP protocol is cheaper equipment simplestructure, stable performance, and has high transmission speed, widely used inindustrial production field of Siemens S7-300,400, etc. The controller is oftenmounted Profibus-DP communication module. The wide variation in standardsbetween the communication protocol, incompatible with each other. So it caused theMODBUS interface device and the PLC device with the PROFIBUS communicationmodule is not directly for data communications. And when the upgrade system,because of each manufacturer product follow protocol is different, the user cannot usedifferent manufacturer of equipment to integrate systems for optimal performance andcompetitive price.By the above circumstances contributed to the development of the gatewaydevice, through the gateway protocol conversion, make the scene with the MODBUScommunication interface connection of communication devices with PROFIBUSinterface, this module USES STM32f103chip, using DP slave station interface chipSPC3chip as intelligence, added6n137photoelectric isolation optoelectronic, inorder to protect the gateway device through flow pressure on site. Through thegateway, you can easily connect the MODBUS network and Profibus-DP network.Implements the MODBUS RTU protocol in communication protocol No.1, No.2, No.3, No.4, No.5, No.6, No.15and No.16function.