| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve the reliability of radio communication under a noise environment, and to realize the overall adoption of a control system to a network. SOLUTION: A transmitted data generating part 118 of a station 100 digitizes data (a control instruction) from a controller 100 into a positive waveform and the inversion waveform, and generates a communication frame to the destination of a station 102. A transmission and reception modem 111 transmits the communication frame by radio with a frequency fl, and a transmission and reception modem 112 transmits it with a frequency f2. Transmission and reception modem 131 and 132 of the station 102 at an operating terminal side receive the communication frame with each frequency f1 and f2, and store it in a reception buffer 134. An inversion check part 135 operates the parity check of data for each frequency, and judges that the data are normal when one positive waveform and the inversion waveform are completely inverted. When both of them are asymmetrical, a data reproducing part 139 puts together normal parts bit by bit, and reproduces normal data.</p> |
