Master apparatus and slave apparatus and time-synchronization method

摘要

A master apparatus repeatedly executes an offset value calculation notification sequence in which a calculation of an offset value for correcting a transmission path delay is implemented after communications with the plurality of slave apparatuses, and a notification of the offset value calculated to the plurality of slave apparatuses is implemented Every time the offset value calculation notification sequence is executed, the master apparatus notifies the slave apparatuses of a sequence identifier which is the identifier of the offset value calculation notification sequence. Furthermore, the master apparatus selects a sequence identifier from among two or more sequence identifiers already notified to each slave apparatus, notifies the selected sequence identifier to each slave apparatus, and instructs each slave apparatus to use, for time-synchronization, an offset value notified in the offset value calculation notification sequence corresponding to the selected sequence identifier.

主权项

1. A master apparatus which is connected to a plurality of slave apparatuses via a transmission path and performs time-synchronization with the plurality of slave apparatuses, comprising:
a sequence executing circuit that repeatedly executes an offset value calculation notification sequence in which an offset value for correcting a transmission path delay is calculated after communications with the plurality of slave apparatuses, and the offset value calculated is notified to the plurality of slave apparatuses; a sequence identifier notifying circuit that notifies the plurality of slave apparatuses, every time the offset value calculation notification sequence is executed by the sequence executing circuit, of a sequence identifier which is an identifier of the offset value calculation notification sequence; and an offset value instructing circuit that selects a sequence identifier from among sequence identifiers previously notified to the plurality of slave apparatuses by the sequence identifier notifying circuit, notifies the plurality of slave apparatuses of sequence identifier selected, and instructs the plurality of slave apparatuses to use, for the time-synchronization, an offset value notified in the offset value calculation notification sequence corresponding to the sequence identifier selected, wherein the offset value instructing circuit selects the sequence identifier from the sequence identifies previously notified in response to detection of instability in the transmission path delay.