A high precision clock synchronization algorithm for the EtherCAT
Jingmeng Liu, Long Yang, Dong Xu, Xingming Wu · 2017
EtherCAT (Ethernet control automation technology) has the advantages of high speed, high efficiency and many kinds of physical topology. EtherCAT uses distributed clock technology to achieve precise clock synchronization between slave nodes. It is especially important for the precise clock synchronization in the real-time control system. The crystal oscillator of slave stations will lead to tiny difference of the timing cycle between them. Transmission process of data frame between the different stations also produce delays. These clock synchronization delay errors will affect the performance of real-time systems. In order to minimize the error and improve the real-time performance of the system, it is necessary to study the EtherCAT clock synchronization algorithm. This paper presents a high precision clock synchronization algorithm which is based on the improvement of the clock synchronization algorithm of EtherCAT. Toolbox Truetime is a simulation toolbox based on Matlab/Simulink, it can be used to simulate distributed real-time control systems and network control systems. The feasibility of the algorithm is verified by Truetime toolbox, and the new algorithm has high precision.