| 摘要 |
PURPOSE:To simplify the wiring and improve the reliability, by outputting signals which are obtained by modulating control information, which are addressed to a pair of signal lines connecting a control device and plural devices to be controlled, by a prescribed frequency. CONSTITUTION:Peculiar addresses are given to signal converting circuits 11-14 respectively. When a control device 1 selects and turns on, for example, a TV2a in address 0, and ON is given as control information to the first output terminal and is sent to a circuit 10. The circuit 10 converts an input parallel signal to a serial signal and modulates it by an assigned frequency and supplies it to a signal cable 17. Circuits 11-14 select and demodulate a receiving signal through a BPF and convert the receiving signal to a parallel signal, and they takes in a control signal if the address of control information coincides with their own addresses. Next, the circuit 11 transmits a signal indicating the receiving from the first input terminal to a cable 17 by similar procedures. The device 1 compares transmission data with data received through the circuit 10, and the device 1 reports an abnormality or retransmits data if the comparison result is abnormal. |
