| 摘要 |
PURPOSE:To realize an automatic DC continuity test to the subscriber terminal in the answer mode as well as the measurement of resistance of the DC loop, by securing an automatic transmission of the call signal to the subscriber terminal of an automatic switchboard and then having a connection of the test unit. CONSTITUTION:The channel within the network NW11 is closed at the time designated by the typewriter command, and thus the subscriber line automatic test unit 10 is connected to the designated subscriber 12 to be tested. At the same time, the time limiting circuit 2 gives a control to the measuring circuit 6 with the signal supplied from the start lead 1 to perform the measurement of both the insulated resistance and the capacity of the subscriber line in the nonanswer state. And the result of measurement is stored in the circuit 6. The circuit 2 drives the relay 3 in a lapse of a fixed time to supply the call signal to the subscriber terminal 12 from the call signal lead 8. And with the answer of the terminal 12, the answer monitor circuit 4 drives the relay 5 to carry out the measurement for both the DC continuity test and the loop resistance of the subscriber line in the answer mode. And the result of measurement is stored in the circuit 6. And after the test, the test call is reported to the subscriber from the announcement lead 13. |
