Monitoring And Control Network Systems Based On Can Field Bus

Nowadays CAN field bus is widely used in the industry control because of itsadvantages such as high reliability, good real time performance, low price, and easyrealization. This paper proposes the whole design scheme, system structure and softwaredesign of measurement and control system based on CAN field bus through the analysisof the composing of CAN field bus network and communicating protocol. It alsoproposes the ways to design and realize the constructing of measurement and controlnetwork based on CAN bus. The main tasks finished are as follows:Firstly, a new protocol for user layer communication which is named Proto-Can ispresented. This protocol is based on "order+parameter" and is the form of standardframe.Secondly, the communication software and CAN intelligence control device of slavenodes based onDSP(TMS320LF2407) is designed. It mainly includes modules: theinitialize of CAN intelligence control device, the transmission and the interrupt receptionof the message, the realization of nodes protocol based on user-defined protocol andsubprograms of D/A, A/D.Thirdly, the master node driver with two interfaces has been designed. It canexchange data with USBCAN interface card and other application software, transfer DLLof USBCAN card to realize the connection with the CAN network. The communicationsoftware between master and slave is developed based on user-defined protocolProto-Can through the driver software. Consequently, it further verifies the man-machineinterface of the network, the advancement and practicability of the network in practice.Finally, based on the current situation of the transformer substation and the designrequest, a monitoring example of the transformer substation has been realized. The mainmodules include: the monitoring interface of the transformer substation, the main hookup,history alarm, trend display, and etc. Consequently, it further verifies the advancementand practicability of the network in practice.In a word, the user layer protocol Proto-Can which has been stipulated is expandable,compatible and flexible. The network, based on the protocol, is suitable for both dataacquisition and control situatJ.on. As a result, the distributed control network withmulti-master nodes and multi-slave nodes can be easily realized.