| 摘要 |
PURPOSE:To improve the quality of guard/supervisory service by providing a detection means detecting the disconnection of a communication line and a weak radio wave sending means activated when the disconnection of the communication line is detected by said detection means so as to send disconnection information by means of a weak radio wave and inform it to a guard man. CONSTITUTION:If an abnormity takes place, it is detected by a sensor 80 and informed to a supervisory center by a central processing section 50 and a communication line adaptor 40 via an open line detection section 20 and the communication line 10. Further, a routine sending signal is generated automatically by the central processing section 50 and informed to the supervisory center by the communication adaptor section 40 via the open line detection section 20 and the line 10. In detecting an open line 10, the open line detection section 20 informs it to a weak radio wave sending section 30 through an output line 60. The weak radio wave sending section 30, according to the notice, sends a weak radio wave representing the open notice from an antenna 70. When the open line 10 is restored, the open line detection section 20 informs it to the section 30 to stop the sending of the weak radio wave. |
