| 主权项 |
1. A method of detecting normal personal activity within a dwelling having a plurality of functional spaces with at least one motion detector arranged in each space to be monitored and a control system connected to the detectors to receive activity reports therefrom indicative of detected movement, at least one of the motion detectors being battery-powered and including a wireless transmitter for transmitting an activity report to the control system, in which method the control system:
awaits an activity report from a detector indicative of movement in a space monitored by that detector; awaits an activity report from a detector monitoring another space indicative of movement in that another space; and issues an alert signal in the event an alert period expires following receipt of the first activity report and no activity report has been received from another detector monitoring another space, said alert period being specified by at least one of a user of or the operational characteristics of the system; and when said at least one motion detector detects activity and an activity report is transmitted to the control system, the timing of a minimum reporting period is started to inhibit further activity reports being transmitted by the detector until said period has expired, the detector during this period recording the time of the first activity following starting of the timing and also the time of the latest activity, and on expiry of the minimum reporting period the detector transmits to the control system said times of the first and latest activities. |
