| 摘要 |
PURPOSE:To ensure the processing such as closing of the device and change-over of system quickly, by enabling the detection of failure through the test of transmission and reception time slot unit paired without no relation with other signals. CONSTITUTION:In the test of backward compelled multifrequency signal (MFC signal), contrary to a generic connection, the backward MFC signal transmission designation is made from a central control unit CPU. Further, the backward MFC signal is transmitted from a signal transmission circuit 101 in a time slot tb, and it is received at the signal reception circuit 102 for backward MFC signal reception in the time slot tb through the test connection path TST of a time sharing switch 300 to collate the transmission and reception data. |
