| 摘要 |
PROBLEM TO BE SOLVED: To lower the power consumption by stopping electrifying a subscriber device in subscriber electrifying (local electrifying) operation when station electrification is controlled so that it can be stopped. SOLUTION: An office device 1 connected to a subscriber device 2 through a digital subscriber line 4 is placed in an unelectrified state by stopping the electrification from an electrifying power source 10 with switches 17 and 18 OFF and a communication control circuit 16 performs synchronization control according to a subscriber line start instruction. When synchronism is established, the subscriber device 2 decides subscriber electrifying operation, and an SW control circuit 19 holds the switches 17 and 18 OFF, and when the synchronism is not established, office electrifying operation is decided and the SW control circuit 19 turns ON the switches 17 and 18 to perform office electrification from the electrifying power source 10. |
