| 摘要 |
<p>PROBLEM TO BE SOLVED: To exchange data between units without individually providing communication equipment in each unit, increasing cost and being subjected to a legal restriction by exchanging data by means of a data carrier for holding data. SOLUTION: When data is transmitted to a tag 1 as the data carrier from a writing/reading control unit 10, a communication signal is converted into a PWM signal in accordance with data or the command of host equipment 20 and a transmission coil 13 is driven by a drive circuit 12. The tag 1 converts a biphase signal obtained by demodulating a signal voltage induced to a resonance circuit 4 into a NRZ signal. When data is transmitted from the tag 1 to the unit 10, the oscillation waveform of the transmission coil 13 is subjected to 50% duty ratio PWM-ASK modulation, and residual vibration is generated in a coil 2. The reception coil of the unit 10 receives it, demodulates it and transmits it to equipment 20. Similarly, the unit 30 exchanges data by means of the tag 1.</p> |
