| 摘要 |
PURPOSE:To efficiently and exactly detect a fault in a slave station by transmitting a monitoring signal for monitoring its own station through the time slot of a polling channel which is not being used for a call to its own station. CONSTITUTION:The slave station is provided with a monitoring signal generation circuit 10, a monitoring signal multiplex circuit that time-division- multiplexes a monitoring signal T in the time slot of a polling channel in a string of transmission signals to the master station, and a modulation circuit 40. And further, the slave station is provided with a frequency conversion circuit 50 to convert a transmission frequency signal to the frequency of a reception frequency signal from the master station, an extraction circuit 60 to extract a monitoring signal T from an output signal from the circuit 50, a time division multiplex circuit 70 that time-division-multiplexes the extracted monitoring signal T into a frequency signal received from the master station, a demodulation circuit 80, and a fault detection circuit 90 to detect the presence/ absence of an error in the monitoring signal T time-division-multiplexed in an output from the circuit 80. As a result, the slave station can exactly detect a fault in its own station. |
