基于SCP的CAN节点设计

Design of CAN Node Based on SCP

现场总线Field Bus是当前工业数据总线领域中最活跃的一个领域。已成为工业数据总线领域的一个新热点。随着现代通信技术的发展和工业现场数据交换的需要,现场总线技术越来越得到广泛的使用。CAN总线是工业现场广泛使用的现场总线技术之一,适用于远距离、小数据量的现场应用。本文设计了一个能够适用于现场远距离数据交换的CAN通信节点。设计分为硬件和软件两部分。本文设计中利用CAN总线控制器SJA1000芯片,配合89C52单片机实现现场数据、信息的发送和接收;设置的8键键盘和通过74HC164实现的静态LED显示可以完成节点的参数设置和数据显示等工作;扩展的32K字节存储器可以实现现场数据的缓冲和存储。软件部分设计采用了汇编语言实现。设计的节点支持标准帧和扩展帧两种数据格式,完全支持CAN2.0标准。设计具有低成本,实用性强的特点,具有应用价值。

With the development of the modern communication technology and the requirement of the data exchanging at the control fields, the Field-bus technology is increasingly used in the industrial fields. Control Area Network （CAN） is one of the widely used field-bus, it is suitable to the applications of the remote devices with small data exchanging. This paper aims at the design of a CAN node which can be used in the industrial fields with remote communication requirement. The design includes two parts： the hardware and software. The basic knowledge and the principle of the CAN bus are introduced firstly, followed by the standards of CAN Bus and its applications in the industrial fields. In the design, the chip SJA1000, which is used as the communication controller, together with the MCU 89C52, fulfills the data exchanging of the fields. The 8 keys and the static LED display module based on the 74hc164 can achieve the parameters setting and the information display. The extensive memory is utilized to store or buffer the data. The routine is programmer by using the compile language. The designed node supports the standard frame （11-bit identifier） and extension frame （29-bit identifier）, which is compatible with CAN 2.0. The design has the features of lower cost, high practical application. The design has the practical meaning.