Research Of Multi-fieldbus OPC Server Based On EDDL

The presence and development of fieldbus has brought an involution in industry control field. With its digital,distributed and open character,fieldbus has been a hot issue in control field.The control system based on fieldbus is replacing traditional control system,and represents the orientation of advanced control system.However,the fieldbus is various in styles at present and applied widely in different fields individual.No kinds of filedbus can be totally suitable for all applications.Thus the situation that many kinds of fieldbus coexist will exist in a very long time. Various kinds of fieldbus products are unable to realize mutual operation and cooperating work because of difference of the protocol.In this way,it hinders users' choice seriously.Therefore multifieldbus integration already becomes the inevitable trend.Under the Microsoft's cooperation and the guiding of the OPC foundation,OLE(OLE for process control) was established as the interface standard of the automatic field by the leading manufacturers of the automatic field all over the world.It was based on COM/DCOM technology standard and designed for the information alteration of the process control software.With OPC standard is proposed,it provides an effective solution in the problem of multifieldbus integration. Through adopting OPC technology,every fieldbus can realize information sharing and seamless integration,as well as Plug & Play of fieldbus equipment.The mutual operation and adaptability of multifieldbus is enhanced greatly.However,at present many kinds of field devices exist in control system.With OPC server for system integration developers have need to develop one OPC server for one kind of field device respectly.So development of OPC server is not independent of the type of field devices.the disvantage limits the openness of OPC server,increases the time and difficulty of development,and becomes an obstacle to applicate field devices.meanwhile,OPC server focuses on acquiring real-time data,does not supports no-real-time data such as parameter of function block,type of devices,revision of hardware and software.It's not good to management of devices.EDDL(electronic devices description language) is developed by the three of most popular field foundation:HART,FF,PROFIBUS,and becomes the international standard IEC-61804.this technology can integrate many kinds of field devices quickly,and acquiring all information include real-time data and no real-time data.So this technology is supported by many company such as emerson,simenz. So bring EDDL in OPC server for this problem,and propose EDDL-based OPC server model and realization.Experiments indicates that this model can help control system to integrate various field devices quickly through EDD files,and resolve issue above-mentioned,meanwhile this OPC server can support devices' configuration and management besides exchange of process value.