| 摘要 |
PURPOSE:To exclude a processing specific to a subscriber line test from a controller, by providing a device forming a loop on a channel for a subscriber circuit connecting subscriber lines, to a subscriber line test device, and displaying that the subscriber circuit is under test to an automatic exchange. CONSTITUTION:When a subscriber line test device TST is under test, since a contact ti for display of occupied line is in on-state, even after a subscriber line L is reconnected to the device TST, a loop via the contact ti in said state is formed for the channel of a subscriber circuit LC. The circuit LC succeedingly keeps the call connecting state and in a controller MPR, the circuit LC is regarded as occupied in the process of processing to generic calls. When the test of a subscriber line L is finished with a line LTC and the test personnel restores a subscriber telephone set TEL, the device TST is restored and the contact ti at closing state is released. |
