| 摘要 |
PURPOSE:To reduce the security information collection time in the security system utilizing a CATV line. CONSTITUTION:Intermediate monitors 9, 31 are installed in the system. The intermediate monitors 9, 31 uses frequencies fa1, fu1 according to a polling table down-loaded from a center equipment 1 and collects security information from terminal equipments 16, 25, 30 installed at a subordinate position from the monitors. The center equipment 1 uses frequencies fa2, fu2 to make polling the intermediate monitors 9, 31 thereby collecting security information of the terminal equipment 16, 25, 30. |
