NODE APPARATUS FOR CLOCK SYNCHRONIZATION IN DISTRIBUTED SYSTEM AND METHOD FOR CLOCK SYNCHRONIZATION

摘要

A node apparatus for clock synchronization in a distributed control system and a method for clock synchronization reduce an error due to a rapid variation of a frequency scale factor by applying a weight value to a frequency scale factor to determine a frequency compensation factor. A slave port(221,225,23-1,23-2) receives the clock information transmitted from a host node apparatus and transmits the clock information to the local clock, and transmits the synchronization finishing information informing the termination of the synchronizing process with the host node apparatus to a master port. A local clock receives the clock information from the slave port and changes the clock inside the node device. One or more master ports receive the synchronization completion message from the slave port, and receive the changed clock from the local clock, and transmit the changed clock to the slave node.