| 摘要 |
PROBLEM TO BE SOLVED: To enable selective communication with a responder in the communicatable range of an interrogator by driving the whole responder for modulating a question wave and reflecting the modulated wave when an identification(ID) code transmitted form the interrogator coincides with a responder's own ID code. SOLUTION: An interrogator 50 modulates and transmits an ID code, a command or the like, a responder 51 receives the modulated signal, a detector 5 demodulates the received modulated signal, and an ID code judging circuit 6 extracts an ID code from the demodulated signal and compares the ID code with an ID code previously set in the resonder 51. When both the ID codes coincide with each other as the compared result, a switch circuit 7 is turned on, a control circuit 8 and a modulation circuit 9 start to operate and the circuit 8 extracts a command from the output of the detector 5. When the command is a request for reading out an output from a sensor circuit 10a, the circuit 8 turns the circuit 10a into a driven state and the circuit 9 modulates an unmodulated question wave outputted form the interrogator 50 and reflects the modulated wave to the interrogator 50. |
