| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a security system having a plurality of sensor units allowing reduction in a wiring burden and cost for construction and maintenance and requiring no complicated setting work or communication control. <P>SOLUTION: A controller 1 makes an antenna AT1 effective to supply electric power to a sensor unit SU1. In this way, the sensor unit SU1 is started to transmit detection information from the sensor to the controller 1. The controller 1 carries out processing corresponding to the detection information. Then, the controller 1 makes an antenna AT2 effective to supply electric power to the sensor unit SU2, and consequently, similar processing is carried out. In this way, a switch to a directional antenna AT is carried out to make it effective, and one-to-one radio communication with each sensor unit SU is carried out for gathering sensor information. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
