Application Study On DeviceNet Communication Interface Technology In Electric Power Supervisory Control System

With the rapid development of control, computer, network and communication technologies, fieldbus has been an inevitable trend in industrial automation fields because of its good openness, high reliability, low cost and simple maintenance. DeviceNet originates from CAN bus and is one of the widely used fieldbuses in industrial automation fields at the present time. Compared with the general fieldbuses, DeviceNet has the characteristics of high reliability, good efficiency and flexibility because it integrates some new technologies. However, the research and development on DeviceNet in China is just in the primary period and far behind the market demand.The main content of this dissertation is to design the DeviceNet communication interface for slave devices and the purpose is to apply DeviceNet in electric power supervisory control system. This dissertation concentrates on the following work.Firstly,this dissertation introduces the characteristics and current situation of fieldbus in detail, compares some general fieldbuses and puts forward the solution to the technology barriers of fieldbus. This dissertation also analyses DeviceNet specification and provides the general procedure of communication interface design.Based on DeviceNet specification, this dissertation designs the DeviceNet communication interface starting from the bottom DeviceNet protocol. The 51 serial microcontroller with embedded CAN controller modules and the CAN controller interface are adopted to provide the hardware of the communication interface. The routines of CAN specification and the application routines which realize DeviceNet specification are programmed with C51 programming language and the object-oriented thinking. According to DeviceNet specification, the EDS file is also edited.Finally, an idea of designing the distributed electric power supervisory control system based on DeviceNet, which is helpful to improve the openness, safety and reliability, and a method of designing the DeviceNet communication interface based on PC is given in this dissertation.On the basic of realizing the main function of DeviceNet communication interface, the application and prospect of DeviceNet are discussed effectively in this dissertation.