摘要
分析了CAN现场总线的特点、它在特定的应用场合数据传输过程中存在的问题以及出现问题的原因.基于CAN的底层协议,设计了它的上层协议,借鉴了数据通信中的时分原理,对周期性和非周期性实时数据,设计两种不同的传输模式.解决了CAN的多主式模式中节点随机发送数据存在的信息帧碰撞而产生的信息阻塞问题,并用实验验证了这种通信模式,在总线中数据流量接近饱和时,对实时数据的传输具有很好的特性.
This article analyses the feature of CAN, the problem and its cause in data transmitting in some application situations. Based on the bottom protocols, its application protocols are designed. Employing TDM principle, two kinds of transmission modes are designed for periodic and aperiodic data transmission. The problem of data blockage caused by the CAN data collision existing in stochastic multi-master data sending is solved. It has been proved by experiment that using this communication mode is conducive to real-time data transmission in heavy bus traffic.
