| 摘要 |
PROBLEM TO BE SOLVED: To smoothly analyze a circuit fault by lighting up continuously an alarm lamp when a carrier signal is interrupted after monitoring the carrier detection signal sent from a demodulation part set via an operation part. SOLUTION: A modulation part(MOD) 2 is subjected to the setting control via a control part 6, and an operation part 7 monitors the part 6 to detect a carrier interruption state. Thus, the part 6 monitors the carrier detection signal sent from a demodulation part(DEM) 4 with respect to a carrier interruption detection circuit 10. Then the part 6 continuously lights up a carrier interruption alarm lamp 9 as long as the carrier interruption state is once detected. In this case, it is possible to confirm that the carrier interruption state occurred once in the past by preparing the circuit 10 which monitors the carrier detection signal sent from the DEM 4 and the lamp 9 which displays an alarm signal at a receiving part. As a result, a circuit fault can be smoothly analyzed. |
