When the emergency informer by subline, the center device, and the patrol system null

摘要

PROBLEM TO BE SOLVED: To shorten the time required for periodical report in a security system. ;SOLUTION: An emergency report device 1 and a center device 10 are connected through a telephone line L. At the time of periodical report, the emergency report device 1 calls the center device 10, and it stops calling when a discrimination time T0 elapses after coming of a ringer signal. At the time of report other than periodical report, the device 1 waits after calling until the call is connected by the center device 10. If calling is stopped when the discrimination time T0 elapses after coming of the ringer signal, the center device 10 discriminates this report as periodical report; but if the ringer signal continues over the discrimination time T0, the center device 10 connects the call and communicates with the emergency report device 1 to receive data.;COPYRIGHT: (C)2000,JPO