The aim of this letter is to improve the performance of clock synchronization in EtherCAT networks. Although EtherCAT synchronizes the slave clocks to the reference clock using a distributed clock synchronization mechanism, a synchronization error still exists between them. We propose a method to estimate and significantly reduce this error. In addition, we implement the method within the existing synchronization mechanism without adding an excessive computational load. The experimental results for synchronization performance verify that the proposed method improves the accuracy of clock synchronization in EtherCAT networks.
