SLAVE UNIT, MASTER SLAVE SYSTEM, AND TIME SYNCHRONIZATION METHOD

摘要

PROBLEM TO BE SOLVED: To provide a slave unit etc. for synchronizing a time with a time controlled by a master unit, capable of performing accurate time synchronization.SOLUTION: The time synchronization method comprises: transmitting a time inquiry to a master unit controlling a time; receiving a reply using a time when the master unit receives the time inquiry and a time when the master unit responds as information, from the master unit; calculating a propagation delay time on the basis of a pair of transmission and reception to repeat a cycle determining magnitude relation between the propagation delay time and a threshold value; and correcting a time on the basis of the pair of transmission and reception used as the base of the propagation delay time less than the threshold value.