| 摘要 |
PURPOSE:To make it possible to detect the existence of a data transmission request as to all tributary stations at a time by transmitting a general polling signal from a control station to each tributary station and then by receiving answers from respective tributary stations in time-division mode. CONSTITUTION:When a batch supervisory sequence is sent out of control station 1, each tributary station 3 sends pulse signal S3, given characteristic delay behind output signal S1 of batch/individual supervisory sequence decision device 8, to answer signal transmitter 9, which transmits synchronously the existence of the data transmission request of each tributary station 3 to receiving line R of circuit 2. Control station 1 decodes the signal, showing the existence of the data transmission request from each tributary station 3, sent to receiving line R of circuit 2 by data decoder 6 to detect tributary station 3 making the data transmission request, and after the address of this tributary station is stored in the memory part of data decoder 6, the individual supervisory sequence is sent to the tributary station 3. |
