【作者】 李明远； 贾超； 陈在平； 冷建伟； 张凯；

【Author】 Li Mingyuan~1 Jia Chao~2 Chen Zaiping~2 Leng Jianwei~2 Zhang Kai~2 (1 anjin Instruments group Co.,LTD.Tianjin 300110 China; 2 hool of Electrical Engineering Tianjin University of Technology,Tianjin 300191 China)

【机构】 天津仪表集团有限公司； 天津理工大学自动化学院；

【摘要】 以太网技术进入工业领域的最大障碍就是其原有的CSMA/CD通信机制是一种非确定性的通信方式,而通过对数据链路层进行实时扩展是一种改进以太网确定性的有效方法。本文给出了一种基于此类方法的确定性网络——时间临界值控制网络,该网络将最高优先级的实时数据循环周期作为整个网络的同步周期,通过在同步周期内分时发送不同优先级数据的办法,有效解决了以太网的确定性问题。本文深入分析了该网络的通信机制,给出了该网络的数据链路层架构及其核心组件的状态转移图,然后以某污水处理厂的应用为例,详细介绍了该网络的系统设计方法,证实了其应用的有效性和可行性。更多还原

【Abstract】 The CSMA/CD communication mechanism which uses a non-deterministic method is the biggest obstacle for introducing Ethernet into the industrial field.The effective method for improving the determinability of Ethernet is to extend the data link layer.This paper gives a method based on this kind of strategy——Time-Critical Control Network.This network regards the transmission period of the highest PRI as the period of synchronization,solves the determinability question of Ethernet by scheduling the corresponding data with different PRI in different time slice of a synchronization period.This paper analyse the communication mechanism of Tcnet,and gives the realization method of the ACM by analyzing the TCnet DLL internal architecture.The design method of network system is also proposed by a sewage disposal example to prove its utility and the feasibility.更多还原