| 摘要 |
PURPOSE:To eliminate the manpower for a folding test at the remote station, by providing a folding control circuit for a test of circuit and forming a folding test circuit for circuit with the control signal. CONSTITUTION:A test device 1 is connected to a station A and started with a folded circuit starting switch 6. Thus the earth is applied to a line DL of a channel converting device 3, and the control signal is delivered a line RG of a channel converting device 3' of a station B. Using this control signal, a relay 8 of a folded circuit 7 connected between the device 3' and modulating/demodulating device 2' is operated. Then contacts (a), (b), (c) and (d) of the relay 8 are switched. Here a test signal is transmitted from the device 1 of the station A, and thus the folding signal comes back to the device 1 in a route of the device 2 - the device 3 - a carrying section 4 - the device 3' of station B - the contact (a) - an input/output level corrector 5 - the contact (b). Thus a folding test can be carried out. |
