| 摘要 |
PURPOSE:To transmit efficiently a next data by providing a means ANDing a leading time and a trailing time of a detected carrier detection signal so as to reduce waste time of data reception. CONSTITUTION:A data signal subject to frequency modulation by a data transmitter 1 is demodulated into the original data signal by a frequency demodulator 8-2 of a data transmitter 2' via a transmission line 9 and received by a data reception section 4-2. On the other hand, a data signal subject to frequency modulation is shaped into a limiter waveform A by a level converter 16 and inputted to a monostable multivibrator 17 and a counter 19. A waveform B is obtained from an output of the vibrator 17 and a waveform C is obtained from an output of the counter 19 and a carrier detection signal D having a leading time Ts and a trailing time Tf is formed by inputting them to an AND gate 21. In giving this signal D to a reception section 4-2, the waste of data reception due to the delay in the trailing Tf is reduced and the data is transmitted efficiently. |
