| 摘要 |
PURPOSE:To perform testing without interrupting telephone service for subscribers by connecting a subscriber's terminal cut off from an exchange to a subscriber's interface circuit during testing, and connecting the subscriber's interface circuit during testing to a controlling system. CONSTITUTION:At the time of testing, a relay for testing 3 connects a subscriber's terminal 1 to a subscriber's interface circuit 7 during testing and connects a testing equipment 6 to a subscriber's interface circuit 4. The subscriber's interface circuit 7 during testing has, similarly to ordinary subscriber's interface circuit 4, functions of transmitting ringing signal, supply of speech current, loop monitor, hybrid function, etc. As the subscriber's terminal 1 is connected to the subscriber's interface circuit during testing 7 only at the time of testing, a controlling device 9 makes calling to the subscriber's terminal 1, and able to make services such as calling for other subscriber's terminals 10, incoming indication for the subscriber's terminal 1, processing of outgoing trunk, etc. similarly to the case where the subscriber's terminal 1 is connected to the subscriber's interface circuit 4. |
