| 摘要 |
PURPOSE:To make hardware of a test device simple by selecting a subscriber circuit for measured only by changing over contacts, etc., installed in the subscriber. CONSTITUTION:An incoming terminal LTA for testing respective subscriber lines of subscriber circuits 10A,...,10B is in parallel connected, respective terminals LTB are in parallel connected in the same manner and an oscillator 1 is connected between the terminals LTA and terminals LTB. In the same manner, an incoming terminal NTA for testing respective channels of subscriber circuits 10C,...,10D and respective terminals NTB are in parallel connected and between these terminals NTA and NTB, a level meter 2 is connected. Respective transmitting signal terminals S of the subscriber circuits 10A,...,10B and respective receiving signal terminals R of the subscriber circuits 10C,...,10D are connected respectively. By connecting the circuit, contacts l0 and l1 of a subscriber circuit 10A are closed, and the signal from the oscillator 1 is sent from a oscillating side subscriber circuit 10A to a receiving side subscriber circuit 10C. In the receiving subscriber circuit, contacts n0 and n1 are changed over, a block 1 is connected to terminals NTA and NTB, and a reference signal sent from the oscillator 1 is measured by a level meter 2. |
