| 摘要 |
PURPOSE:To speed up surveillance and maintenance of a transmission line by using a time division transmitting system by polling, performing a photoelectric conversion along with demanding the transmission individually to terminal stations, and making a branching combination for the transmission demand and fault information by a logical circuit. CONSTITUTION:After fault signals transmitted between the terminal stations 4a-4d and a processing device 1 are converted to electrical signals, the fault signals A1, A2 are combined by an OR circuit 9. On the other hand, the transmission demand signal is branched to becomes to the transmission demand signals B1, B2 which are transmitted to each terminal station 4a-4d. The fault signals A1, A2 are transmitted from each terminal station 4a-4d with the time division against the transmission demanded from the processing device 1. The fault signals A1, A2 come from the terminal stations 4a-4d are returned to only the stations 4a-4d with specified address of the processing device 1 corresponding one to one to the transmission demand by the polling from the processing device 1. |
