| 摘要 |
PURPOSE:To enable even a supervised station to exercise a supervision over other supervised stations by providing the supervised unit with a monitor circuit which receives a calling signal from a supervisory station and an answer signal from another supervised station. CONSTITUTION:A calling signal from a supervisory station, inputted to a supervised unit, is decoded by decoder 11 and decoding logic circuit 13 and the decoded signal is stored in station commentary circuit 17. Next, the answer signal of the supervised station to a call from the supervisory station is decoded by circuit 13 and the decoded signal is coded by supervised-information coding circuit 18. By those two pieces of information, the supervised station can be supervised by an associate supervisory station as well as the supervisory station. Consequently, several supervised stations can be supervised by several stations by using one carrier without increasing supervisory units in number and each supervised station requires only one demodulator 11 and modulator 12, so that the reduction in cost and miniaturization of the unit can be realized. |
