| 摘要 |
PURPOSE:To supervise independently a specific channel by providing a means inputting a test signal in place of an analog input signal and a means branching a signal of a time slot of a test signal from the primary group PCM signal to a transmission section and forming a reception section corresponding to the said provision. CONSTITUTION:A test analog input signal is inputted to a changeover channel bus circuit 9. In supervising the transmission side of the n-th channel, only a channel switch circuit 10-n selects a signal of the circuit 9 in place of the analog input signal. The test signal is subject to A/D conversion and subject to time division multiplex by a multiplex section 3 together with the signal being a result of A/D conversion of the input signal of other channels. A data branching transmission circuit 11 extracts a signal of the time slot corresponding to the n-th channel at each frame out of the said multiplex signal and outputs it from a test digital output terminal 12. Then the PCM signal subject to multiple by the multiplex section 3 is transmitted similarly as the normal state. |
