Abstract: Considering the serious systematic distortion when the networked control systems (NCS) have different network loading, this paper introduces a new solution of using suitable network protocols to improve the performance of system, gives a general instruction of the characteristics of four types of network protocols which are Ethernet, CAN, Round Robin and Switched Ethernet, then confirms the different protocols which have different network performances when they are applied to low loading and high loading in experiment by establishing the model of NCS, writing code, adjusting network interference share and choosing different network protocols. This paper comes to a conclusion that networked control systems have better dynamic and stability performance by choosing proper network protocols.

Key words: networked control systems, TrueTime, network protocol, dynamic performance, stability performance