Design Of The Multi-protocol Communication Adapter Based On The Control Network

In the field of industrial control, control network technology is networkautomatic control technology integrated mutually by automatic control technologyand computer communication technology. Distributed Control System, Field BusControl System and Industrial Ethernet are all based on control network datacommunication. At present, the industrial control network development is heading fornetworked communication, data integration, decentralized control and intelligentizedfield equipment.With the development of control network, more and more communicationproblems between field equipments with different serial interfaces and bus withdifferent protocols have become increasingly prominent. This paper designed amulti-protocol data conversion device for industrial control network, it can realizedata multi-function conversion between standard interfaces RS232/RS485/RS42andProfibus-DP/CAN field bus.This paper firstly introduced the technical features of field bus and thedevelopment current situation of multi-protocol communication adapter, mainlystudied and analyzed the operation mode and frame structure of PROFUBUS-DP bus,CAN bus, RS485, RS232, and RS422. Then made the hardware design based on thefunction of communication adapter to be achieved, saved cost as much as possible onthe premise of guaranteeing industrial requirement, the hardware system adaptedW78E58B MCU as main controller, designed software for each communicationmodule, including main program module, PROFUBUS-DP communication module,CAN bus communication module, and serial communication module. Buscommunication primarily used interruption mode to receive and transmit data. Thispaper elaborated the overall goal and structure of software design, and introducedrelevant communication program development.In the laboratory environment, simulated the industrial field environment usingvirtual equipment, tested communication adapter, the tested results indicated that thisdevice can achieve the communication tasks between industrial field equipmentswhich has any kind of standard interfaces RS485\RS232\RS422and any kind of fieldbus PROFUBUS-DP bus/CAN bus.