Reasearch Of Industrial Contorl Network Based On Opc Technology And Heterogeneous System Integration

With the development of industrial control network, it has already formed some network control systems such as Distributed Control System, Fieldbus Control System and other industrial control networks. But because of control network develop in high speed of communication and open structure of system, and there were lots of control networks existed, they could only monitored relate field equipment, and were difficult to achieve in the communication between network, there also had " islands of automation" problem, so these systems had seriously restricted the development of Automatic Control Network. Integration of industrial control network is to put these different types of control network and control equipment integrated in the same platform, and to realize integrated automation system.Through studying the integration of industrial control network, this paper has proposed using Industrial Ethernet as a net platform which integrated to other kinds of control system; in communication, it has unified the interface of communication by OPC(OLE for Process Control) technology. Finally, the Integration Scheme of industrial control network was determined by the Industrial Ethernet based on OPC technology.OPC interface technology is a kind of industrial communication interface standards which can provide high-efficient information integration and data exchange function, so the Industrial Ethernet network can use this technology to make different manufacturer’s products exchange data unblocked, it has extensive development prospects in industrial control network. Using the network platform of Industrial Control Network Laboratory exist in university, this paper has realized the communication between monitoring software of host computer and S7-400PLC (Programmable Logic Controller)by OPC technology, there were Siemens PLC as OPC server and VB(Visual Basic) as OPC client, through the OPC server program of Siemens own and the corresponding hardware, then combined with the OPC client program what VB writes, in order to realize data exchange and real-time monitoring between devices in control system. Finally, OPC technology has made control system to realized control integration.Through the man-machine interface system of the whole network which developing by VB, it can prove that Industrial Ethernet based on OPC technology could meet the high-speed requirement of open control network integration in actual operation by testing Fans Online Monitoring system as the specific control object. While using Siemens PLC to construct the network, also try to parallel monitoring different communication system such as Mitsubishi FX2N PLC which incorporated into the network, and the integration of heterogeneous system was realized. When studied the communication principle of relevant controller, this paper have confirmed that use common RS232/485bridge module to finish inter communication between two different kinds of Programmable Logic Controller. Through analyzing the receiving data message format of s bridge module, It could ensure that the communication between two different Programmable Logic Controllers were stability and integrity through RS232/485bridge module data transformation. So it was proved the probability of the Heterogeneous System Integration.Through research Industrial Ethernet based on OPC technology and Heterogeneous System Integration, this paper investigates the two aspects of technology realization:on the one hand, different control system can be integrated in a network, and make Field Data can be accepted by Upper Computer or between control systems; on the other hand, heterogeneous system of PLC which widely used in the industrial field could realize communication integration, made PLC of different systems to communication each other through protocol conversion module.Using the two solutions to reform the exist network of industrial control network laboratory, so there were more selective to control network laboratory, and students could contact and understand more control equipment, that would have a very good teaching effect. Meanwhile, that was also provide an effective and feasible scheme in the realization of the control integrated process, there is an important application value.