Design Of RTU Device Based On CAN Bus

With the development of science and technology in our country, automatic system which is used in the fields of electricity, water conservancy, water supply, railways and aerospace develops greatly. The remote terminal is an absolutely necessary equipment in these automatic systems. At present, kinds of industry’s demand on electric power energy is constantly increasing, so that the amount of transformer substation increases, the power level improves and the power supply range enlarges. If transformer substation adopts traditional master-slave to communicate in peer to peer, It is more and more difficult to meet the transformer substation’s demands,which are transformer substation’s running safety and economically and fewer person on duty or even unattended duty to. So research in the remote terminal device which is based on computer technology and network communication technology has became a problem which is urgently to be solved.This design adopts CAN bus as a communnication carrier to build a remote terminal. This acticle introduces the whole design scheme. It also combine singlechips control and software synchronous sample to design the hardware circuits and software segements. It also has accomplished hardware and correlative software of current and votlage input circuits remote measuring, remote signal, remote control circuits, keybroad/display interface circuits, reactive power positive and negative judging circuits, CAN bus communication interface circuit etc.MSP430 microprocessor is used as host processor and CAN bus is used as communication network in this device,. The performance of RTU includes real-time response, data communication and signal processing is highly improving. The device can not only measure ac parameters of substations but also can communicate with monitoring host computer through CAN network, so that dispatching control room can real-time monitors and controls the operation state and parameters of substations.The remote terminal device based on CAN bus designed in this paper, which is easy-to-use, high accuracy, high reliability, easy to network, high performance price ratio, has some practical application value.