| 摘要 |
<p>PURPOSE:To enable the measurement of transmission loss and status monitor time- serially, by monitoring the level variance and momentary interruption, through the comparison between a measuring signal and a scheduled threshold level, and by obtaining the transmission loss through the comparison of the measuring signal with the reference signal. CONSTITUTION:A measuring signal is rectified and the level is stored at a holding circuit 9. A measuring control circuit 13 monitors the state until an input is given to the circuit 9 and it is interrupted at the initial set, and if the interruption is detected, the circuit 13 gives instruction so that a holding signal is outputted to a comparison circuit 12 for the circuit 9 and a reference voltage is to it for a D/A conversion circuit 11. The circuit 11 outputs a compared output from the circuit 12 to an operation circuit 19, which subtracts the specified value from the comparison signal and stores the value as the result of transmission loss measurement. When the count of a time limit set circuit 14 is finished, a monitor circuit 15 compares the output from a level set circuit 16 with the preset threshold level to discriminate the level variance and momentary interruption.</p> |
