An open CNC system based on switched ethernet

The switched Ethernet, which has many features for real-time communications such as micro-segmentation of network traffic and full-duplex links, has become one of the hot research issues toward real-time Ethernet. This paper proposes an open CNC system based on the switched Ethernet including the star topology architecture and the real-time communication mechanism according to the character of traffic flows in the CNC systems. To achieve the real-time performance, a service cycle of the switch is divided into two parts for hard real-time applications and other applications respectively and a feasibility check algorithm is introduced as the admission control. Finally the implementation of a prototype system is described and the results based on the prototype system show this method is feasible and effective.