摘要 |
Indicating a movement of an ultrasonic tag is accomplished by a transducer operable to provide electrical signals caused by the movement. The movement can cause mechanical vibrations, sound vibrations, or pressure in the transducer, to generate the electrical signals. A controller can detect the electrical signal from the transducer generated by the movement, whereupon the controller obtains tag data and modulates the tag data to be supplied to a powered up emitter. The emitter transmits the modulated tag data in a transmission to an ultrasonic tag reader using an ultrasonic carrier sound wave.
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