| 摘要 |
PURPOSE:To realize economically a power application indication from plural lines by giving the power application indication to a terminal controller when a telegraphic message the same content as that of a telegraphic message memory for power application within a supervised time. CONSTITUTION:A signal scanning circuit 2-7 for detecting a carrier signal and an incoming signal, line switching circuit 2-6, and control memories (a memory storing in advance a telegraphic message for power application, timer setting memory storing in advance a supervising time of a received telegraphic message and a line supervising memory storing the presence of necessity of line supervision according to the presence of the carrier signal and the incoming signal) 2-4 per each line are provided. The presence of the carrier signal and incoming signal of each line is checked sequentially by the circuit 2-7, the circuit 2-6 is switched in order to supervise the received telegraphic message of a line transmitting the carrier signal and the incoming signal, and when the telegraphic message having the same content as that of the power application telegraphic message memory is received within the supervising time decided by a supervising time setting memory, the power application command is transmitted to the controller 3. |
