| 摘要 |
PURPOSE:To make small in size and simplify the channel test circuit at line and time sharing exchanger side, by inserting and picking up the signal on designated line only through the conversion circuit of analog and digital signal through the inserter.dropper. CONSTITUTION:When the line side of a time sharing multiplex line 1 is tested, first the time sharing multiplex signal input from the reception terminal gamma is received and only the signal of the time slot T corresponding to tested line is transferred to an A/D and D/A converter 4 through an inserter.dropper 2b at the line side. Further, it is D/A-converted at the converter 4 and received at handset 6. Further, the signal from the handset 6 is A/D-converted at the converter 4, inserted to the time slot T with the inserter.dropper 2a at the feeding line side and transmitted from an output terminal alpha. Thus, the channels between the handset 6 and the subscribers at the line can be assured. Further, in testing the exchanger side, it is similarly made by using a D/A converter 5 and a handset 7. |
