| 摘要 |
PURPOSE:To detect a fault distinguishingly a fault of exchange side and subscriber line side regardless of operating/busy state of a telephone set by providing a fault diagnostic device between the exchange and the subscriber line. CONSTITUTION:The fault diagnostic device comprising a monitor/fault detecting circuit 3, a talking detection circuit 4, a switch circuit 5, an incoming detection circuit 6, an incoming input circuit 7, a switch drive circuit 8, an AC bright circuit 9, an oscillating circuit 10, a call detection circuit 11, a fault detection circuit 12 and data recorders 13, 14 is provided between an exchange connecting terminal 1 and a subscriber line connecting terminal 2, the incoming to and outgoing from a telephone set are conducted by the fault diagnostic device so as to detect and record independently a fault of the exchange side and the subscriber line side. |
