| 摘要 |
PURPOSE:To prevent radio interference of a transmission signal by providing a radio interference discriminating section and a transmission stop signal transmitting section to a central controller, and a control section stopping the transmission of signal to a terminal device. CONSTITUTION:The bidirectional communication system is constituted by connecting the central controller 2 and many terminal devices by means of one signal cable with branching. The central controller 2 having a converter section 21 transmitting a return signal converting a carrier frequency of a transmission signal from each terminal device is provided with the radio interference discriminating section 23 discriminating the presence of radio interference by detecting an amplitude modulating component of the received signal and a transmission stop signal transmitting section 26 transmitting a tansmission stop signal when the radio interference is detected. The transmission control section 14 provided to each terminal 1A stops the transmission of the transmission signal for an optional time when the transmission stop signal is received. |
