| 摘要 |
PURPOSE:To improve the data transmission efficiency and the utilizing efficiency of a line by abolishing demodulated data after the demodulated data is inputted once if no radio reception signal is inputted after a prescribed delay time. CONSTITUTION:A reception demodulation circuit 1 receives and demodulates a received radio wave A, outputs a demodulated output data signal B or outputs a radio wave reception signal C when the received radio wave A of a prescribed level or over is inputted consecutively for a prescribed time or over. Signals B and C are inputted respectively to a processing circuit 4 via input circuits 3, 5. A synchronizing signal and data are inserted to the signal B in succession to a preamble of a short time whdth and the resulting signal is inputted immediately to the circuit 4 when the radio wave A is received. The signal C is inputted to the circuit 4 at a delay time Td after the start of reception of the radio wave A. The circuit 4 receives always the signal B, fetches the succeeding data after the synchronizing signal is detected, and checks the signal C fetched at the completion of the succeeding data fetch, and if the signal C is not inputted yet, the data is abolished as the ineffective data to prevent the processing of erroneous data. |
