光纤CAN总线集线器及其组网研究  

Study on a fiber-optic CAN hub and its networking

作　　者：魏丰[1] 潘小虎[1] 曾勇[1] 丁洪林[2] 

机构地区：[1]华中科技大学控制科学与工程系,武汉430074 [2]中航工业第一飞机设计研究院,西安710089

出　　处：《仪器仪表学报》2011年第12期2839-2844,共6页Chinese Journal of Scientific Instrument

摘　　要：目前国际上还没有以光纤为传输介质的CAN总线物理层标准。提出了一种以光纤为传输介质的CAN总线集线器和基于该集线器的组网方法(已申请专利)。在总结了双绞线介质CAN总线物理层3个特点的基础上,详细讨论了该集线器的工作原理和设计方法。集线器采用了可编程逻辑器件的逻辑"与"替代双绞线CAN的"线与",并将"与"后的信号回传实现了所有节点对总线状态的监听功能,确保了所构造的光纤CAN总线网络在物理层之上与现有的CAN总线标准完全兼容。还介绍了光纤CAN总线集线器的级联扩展方法和与双绞线CAN总线子网的连接方法。实际设计了一个八口的集线器,初步的通信测试验证了方案的正确性和实用性。研究的结果对CAN总线新标准的提出有非常积极的意义。At present, no standard is defined for the fiber-optical transmissions of CAN signals. A fiber-optic CAN hub and the scheme of constructing CAN network based on the hub （patent pending） are proposed in this paper. After a summarization of the three features of the physical layer of twisted-pair CAN bus, the working principle and the design method of the hub are discussed in detail. Through replacing the ＂Wire-AND＂ in twisted-pair CAN with CPLD ＂AND＂ logic and enabling the bus monitoring function of the nodes by sending the ＂ANDed＂ signal back to them, the fiber-optic CAN bus is completely compatible with the existing CAN standard above the physical layer. Two methods of expanding the fiber-optic CAN bus are also described. An eight-port prototype hub was implemented and test result proves the correctness and feasibility of the proposed scheme. The research work is very important to the promotion of new physical layer standard of CAN bus.

关 键 词：控制器局部网 现场总线 光纤通信 集线器 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]