| 摘要 |
PURPOSE:To design a proper system maintenance plan earlier by providing a means which variously changes the phase of a timing signal supplied to a identifying and reproducing circuit in accordance with the command from a terminal station to detect the code error rate and sends it as a monitor signal to a terminal station. CONSTITUTION:The signal having a low frequency which is obtained by dividing the frequency of the timing signal reproduced by a timing generating circuit 6 by a prescribed frequency division ratio is outputted from a frequency dividing circuit 12, and the phase of the timing signal supplied to a identifying and reproducing circuit 4 is changed with this relatively long period and the degree of modulation designated by the terminal station. A supervisory and control circuit 7 detects the variance width of the code error rate accompanied with the phase change of the timing signal and sends it as a supervisory signal to the terminal station. The terminal station receives this supervisory signal to detect the degree of margin of the identifying and reproducing operation for the phase deviation of the timing signal in accordance with relations between the designated degree of phase modulation and the sent code error rate. Thus, the proper system maintenance plan is made earlier. |
