| 摘要 |
A synchronization frame reception unit (214) receives a synchronization frame which is repetitively transmitted from a master device (1) and in which a reference value for time synchronization with the master device (1) is described. Each time the synchronization frame is received, a propagation delay calculation unit (204) calculates a propagation delay of the synchronization frame. Each time the propagation delay is calculated, a propagation delay time zone calculation unit (206) adds a target value of synchronization accuracy to the propagation delay, thereby calculating a propagation delay time zone. A propagation delay group calculation unit (208) implements the logical addition operation of M propagation delay time zones calculated for M synchronization frames preceding the latest synchronization frame (where M ≥ 2). A synchronization determination unit (211) determines, on the basis of the propagation delay of the latest synchronization frame and the result of the logical addition operation of the M propagation delay time zones for the M synchronization frames, whether to use, in the time synchronization with the master device (1), the reference value described in the latest synchronization frame. |
