JPS6478544A - Network synchronizing device - Google Patents

Abstract

PURPOSE:To prevent an error from occurring in the communication between most stations by selecting a clock synchornized with the most significant clock of the hierarchy when a clock form a high-order station is not received, and making the network synchronized with said clock. CONSTITUTION:In case a clock to be transmitted to the low-order station is synchronized with that of the high-order station, a synchronized clock oscillation circuit 1 inserts the hierarchical number of the synchronized station by its inserting means 6, then transmits the clock. In case of not receiving the clock of the high-order station, the hierarchical number of the self station is read out from a memory means, and the number is inserted by the means 6 and then transmitted. In the low-order station, the hierarchical numbers are extracted by extraction means 3, 4 from the clocks inputted from the plural high-order stations, so that a selection means 5 selects the clock in the hierarchical number of the station in the most significant station of the extracted numbers. The selected clock is transmitted to the circuit 1 to synchronize the circuit 1 with it. As a result, even if a clock signal can not be received, the self station can be synchronized with a clock synchronized with the clock in the most significant clock of the hierarchical numbers among the clocks inputted from the plural high-order stations.