| 摘要 |
PURPOSE:To collect the status change in a short time by commonly using a contension system, by setting a start reception time to the system and transmitting a start signal with a different time interval until the starting is received to each terminal device. CONSTITUTION:The change in external state such as failure in distribution lines 5 is detected 19 and applied to a transmission data editing circuit 18. On the other hand, when a change is caused to the external state and external contact control is not performed, a control signal is transmitted to a transmission control circuit 17 with a specified start interval from a start control circuit 23 with a signal from the circuit 19 and a start signal is formed with a circuit 18. When this start signal is received at a central device (not shown), a start/stop signal is transmitted to the central device. When this start signal is received at the terminal device, a stop signal is outputted from a reception control circuit 16 to a circuit 23 to stop the transmission of the start signal. |
