| 摘要 |
A line monitoring device for use in a two-way data communication system such as a CATV system in which up-signals are transmitted by terminal units in response to retrieving signals applied thereto from a central facility to monitor the levels produced by the various terminal units. An address detection signal compares the address number included in a polling down-signal from the central facility with an address prestored in the monitoring device. A response signal detection section detects the up-signals from the terminal units. A display section operates in response to the address detection section to display the level of an up-signal from a terminal unit as produced on the output of the response signal detection section when the address received from the central facility coincides with the pre-stored address. |
