DATA CARRIER SYSTEM AND ITS CONTROL METHOD

摘要

PROBLEM TO BE SOLVED: To avoid collision of signals from plural responders and to stably perform data communication by providing a responder (data carrier) with an output control means which permits/inhibits output of the modulated signal of its modulator circuit. SOLUTION: Responders 1a and 1b have just the same configuration. Received data sent from an interrogator 2 and demodulated by a demodulator circuit 14 of a responder 1 is sent to a control circuit 16. Transmission data which is sent from the circuit 16 to a modulator circuit 13 is modulated by the circuit 13 and outputted from a coil 11 at the time of transmitting to the interrogator 2 side. In such a case, the circuit 16 of the responder 1 which is allowed to output by the interrogator 2 makes a line L13 an output allowable state and the circuit 16 of the responder 1 which is forbidden to output makes the line L13 an output inhibition state. The circuit 13 receives an output control signal sent from the circuit 16 and selects the permission and inhibition of a signal output to a line L10.