| 摘要 |
PURPOSE:To perform a digital trunk test, without reduction of usable channels in a commercial digital multichannel, by switching one channel out of the channels into a test channel. CONSTITUTION:Switches t1, t2 are activated with a test signal from a test stand TST to take a commerical digital multichannel side and a terminator DTI at the same time. A channel to be tested in the commerical digital multichannel designated with a test signal is accessed to connect the designated test channel in the terminator DTI and a test channel TSTDT1 opposingly. The call and control signals at the commercial digital multichannel side of the channel to be tested are branched at the switches t1, t2 to be connected to a spare channel RSVDT1 being a prescribed relation with the TSDT1 at the same time. Thus, a test call can be produced to the TSTDT1 and a commercial call can be incoming to the RSVDT1. |
