| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a guard state setting apparatus mounted with a radio frequency non-contact information identification system using a radio wave for detecting a broken antenna element for transmitting an interrogation radio wave. <P>SOLUTION: An information storage medium 3 is fixedly placed at a prescribed position within a range at which an interrogation radio wave sent from an antenna 10 arrives in the inside of the guard state setting apparatus 1. A main control section 14 transmits an interrogation radio wave transmission command to a transmission/reception control section 13 by each prescribed period. Thus, the antenna 10 transmits the interrogation radio wave. The information storage means 3 transmits a response radio wave every time the medium 3 receives the interrogation radio wave. The main control section 14 judges the apparatus to be normal when the response message is registered in advance of judges the apparatus to be not normal when a regular response message is not received for a prescribed number of times even in a timing when the response message is to be received or no regular response message is received within a prescribed time after the regular response message is previously received and informs a guard apparatus about it via a communication line 16. <P>COPYRIGHT: (C)2004,JPO |
