| 摘要 |
PURPOSE:To enable a subscriber to know that the exchange is under test by connecting a subscriber's terminal separated from an exchange to an interface circuit for subscriber during test and connecting the subscriber's terminal to an announcement transmitting circuit when calling from a telephone subscriber under test is detected. CONSTITUTION:Normally, a relay for test 3 connects a subscriber's terminal 1 and a subscriber's interface circuit 4 and separates a testing equipment 6 from the subscriber's interface 4. At the time of testing, the relay for test 3 connects the subscriber's terminal 1 to a subscriber's interface circuit 7 during testing, and connects the testing equipment 6 to the subscriber's interface circuit 4. A controlling device 9 monitors calling of the subscriber's terminal 1 through the subscriber's interface circuit 7 during testing, and when calling is detected, connects the subscriber's interface circuit during testing 7 and an announcement transmitting circuit 8 by a network 5, and sends out announcing to the subscriber's terminal 1. |
