基于交换式以太网的数控系统通信和时间同步机制

Communication and Time Synchronization of CNC Systems Based on Switched Ethernet

以交换技术为基础的交换式以太网采用了全双工和微网段工作方式,避免了总线冲突,大大提高了以太网的实时性能,逐步成为以太网实时性问题的一个重要研究方向.本文在分析数控加工过程中数据流特点的基础上,研究了将交换式以太网作为数控系统通信网络的实时通信机制和时间同步问题,设计了交换机的服务策略和基于网络演算理论的调度算法,提出一种以交换机为主时钟的时间同步方法.经过原型系统验证表明这种基于交换式以太网的数控系统能良好的满足数据加工要求.

The switched Ethemet, which has many features for real-time communications such as micro-segmentation of network traf- fic and full-duplex links, has become one of the hot research issues toward real-time Ethemet. According to the traffic model of the CNC system, this paper proposes the service disciplines and scheduling of switches for guaranteed real-tile performance in CNC systems. A time synchronization method, which uses the switch as master clock, is also presented. Finally, a prototype system is developed and it shows that this method is effective and feasible