| 摘要 |
<p>PROBLEM TO BE SOLVED: To share the correct time data among a plurality of security devices. SOLUTION: Among security devices 1-N for the security of a plurality of machines composing a machine security system, a receiving device RX for receiving the standard time data STD is mounted on at least one of a plurality of security devices 1-N, and the standard time data STD obtained by the receiving device RX is transmitted to the desired security devices not having the receiving device RX through a distribution line. Whereby the correction of time of high accuracy in time can be efficiently performed by an electric power line carrier technology, and the correct time data can be shared among the security devices 1-N for the security of a plurality of machines.</p> |
