| 摘要 |
PURPOSE:To attain both concentrated control of load and concentrated monitor of terminal device by providing a means to a main control board to confirm the presence or absence of the preceding send-back signal and to decide the sent- back signal as a normal monitor signal only when the sent-back signal exists. CONSTITUTION:A main control board 1 transmits the transmission data to give an access to a terminal device 3 and confirms the presence or absence of a sent- back signal. The sent-back signal is demodulated by a sent-back signal demodulating circuit 18 to be supplied to a control circuit 16 as the reception data. A sent-back signal deciding part 30 is connected to the circuit 18 to confirm the presence or absence of the preceding sent-back signal and then defines the preceding sent-back signal, if exists, as a normal monitor signal. When the part 30 decides the presence of the preceding sent-back signal, the board 1 decides whether the preceding data is equal to that of this time which are stored in the 1st and 2nd data storage parts 20 and 21 respectively. If both data are not equal to each other, the monitor state display of a load 4 is changed or the control state of the load 4 is changed. |
