| 摘要 |
PROBLEM TO BE SOLVED: To invite a worker in a monitoring area of a security system to pay more attention to the security system.SOLUTION: A warning information system comprises a communication device 1, a portable terminal device 6 and a control device 2. The communication device 1 has a communication area 4 including areas in which sensor targets 5 are installed. The portable terminal device 6 transmits information including a measurement result of field intensity of a radio wave received from the communication device 1 and its own ID to the communication device 1. The control device 2 performs control whether to transmit warning information to the portable terminal device 6 according to a result of comparison between the measurement result of field intensity transmitted from the portable terminal device 6 and a field intensity threshold corresponding to a transmission frequency at which warning information was transmitted to the portable terminal device 6 in the past or a reception frequency at which warning information was received by the portable terminal device 6 in the past. |
