| 摘要 |
<P>PROBLEM TO BE SOLVED: To properly recognize a positional relation between an antenna part and an RFID tag. <P>SOLUTION: In order to recognize the positional relation between the RFID tag 10 moving along a determined route and the antenna part 2, the intensity of a carrier wave in a state of not communicating with the tag 10 and the intensity of a reception level of a response signal from the tag 10 to a specific command are measured in a communication control device 3, and each measured value is collated with a plurality of reference values registered in an internal memory. A reference value representing a transmission level suitable for starting the tag and reference values representing a range of the reception level suitable for communication are registered in advance in the memory. When the transmission level satisfies the reference value while the reception level is lower than the range suitable for communication, the antenna part 2 and the tag 10 are recognized to be too much separated from each other. When the transmission level is lower than the reference value or the reception level is higher than a range indicated by two reference values, the antenna part 2 and the tag 10 are recognized to be too close to each other. <P>COPYRIGHT: (C)2010,JPO&INPIT |
