| 摘要 |
<p>A fire alarm system includes a control unit which communicates with a plurality of spaced apart smoke detectors by a bi-directional communications link. The smoke detectors are separate from one another, and spaced apart, and are associated together in different, overlapping groups. Each group of detectors is physically arranged with the members of the group adjacent to one another in a relatively localized area. Signals from the detectors are transmitted to the control element for processing. The control element squares each of the signals for a given group, sums those signals and then takes a square root. The resultant processed value is associated with a selected one of the detectors of the group. Similar processing takes place for each of the groups. As a result of the processing, each of the detectors has associated therewith a processed smoke value which takes into account not only values received from the associated detector, but also values received from one or more adjacent detectors in a group. The processed signal values can then be compared to an alarm threshold to determine whether or not a fire condition is present.</p> |
