Performance Evaluation And Application Of Ethernet Used In Control Networks

With the development of communication and integrated circuit technology, Ethernet application gradually increases in control networks. Compared to traditional industrial control networks, Ethernet uses uniform protocol and easy connects with Internet. However, because the medium access control methods, queue management mechanisms, and network congestion in Ethernet, time delay, jitter, or packet loss will inevitably happens. So the real-time and stability of Ethernet have been an important field of control networks.In the context of networked control for induction motor, by using the network simulation software NS-2, some network models based on UDP are constructed, and then some related experiments are designed. Some analysis that is caused by queue management mechanisms and network congestion is done. Finally, a new UDP is planed that includes congestion control mechanism and tested in NS-2.On this basis, TCP/IP is embedded in network nodes as the software. Some control nodes with Ethernet are designed. And then, a network monitoring system of induction motors is constructed. The functions of this system includes:rotate speed regulation, state for motor, remote monitor and information display.The method of NS-2 simulation can provide one controllable and replicable network environment. It is an important way for control networks design, test and protocol analysis. Some simulation and experiments result shows that performance of Ethernet used in control network of induction motor is verified. It has been complished that high speed data transforms between PC and network nodes. The system will provide an environment for sensor networks research.