Internode synchronizing device, and internode synchronizing method

摘要

Node synchronization slave apparatus 131 detects a timewise variation in the time of arrival of a data frame transmitted from node synchronization master apparatus 111 via cable transmission path 152, and based on the variation in the time of arrival, calculates a predicted value of the time of arrival of a data frame to be received next and thereafter. When the predicted value of the time of arrival indicates late arrival of a data frame and the arrival of the data frame is out of a reception window, the apparatus 131 notifies node synchronization master apparatus 111 of the predicted value of the time of arrival. According to the notification, node synchronization master apparatus 111 advances a transmission timing of a data frame than a reference value in order for the data frame to be received within the reception window. It is thereby possible to decease the frequency with which data is lost due to late arrival of the data even when transmission delay varies on a cable transmission path connecting the nodes.