Appendix C: AWACS™ Applications AWACS Features
86
NFS-640 Programming Manual P/N 51333:B 10/03/2003
Self-Optimizing Pre-Alarm
You can set each detector, except FST-751 (Heat), for Self-Optimizing Pre-Alarm (PA=1). In this Self-
Optimizing mode, the software measures the normal peak analog readings and sets the Pre-Alarm level
just above these normal peaks. This allows extremely sensitive Pre-Alarm capability with reasonable
protection against non-fire signals. The figure below shows a graphical representation of the Self-
Optimizing Pre-Alarm level:
Figure 26 Self-optimizing Pre-Alarm Level
For more information on setting Pre-Alarm levels, refer to the following sections:
• “How to Change Sensitivity for a Detector” on page 48
• “How to Use the Detector Sensitivity Screen” on page 48
Detector Sensitivity
The control panel provides nine Sensitivity Levels for alarm detection and pre-alarm as follows:
Note: For a list of all detector sensitivity levels, see Table 30 on page 90.
• Alarm Sensitivity Levels You can select the sensitivity of a detector from 1-9 (1=highest
sensitivity; 9=lowest sensitivity).
• Pre-Alarm Sensitivity Levels You can select one of nine levels from 1 to 9 (0=no Pre-Alarm,
1=self-optimizing, 2=highest sensitivity, 9=lowest sensitivity). You can set Pre-Alarm
operation to Action (latching) or Alert (non-latching) and to activate Special Zones. For
instructions on programming, refer to “How to Select a Pre-Alarm Level” on page 89.
You can set the sensitivity levels as fixed or programmed for day and night operation. For details, refer
to “Time Control Zones” on page 82.
A sample sensitivity window for a laser detector:
Figure 27 Sensitivity Levels for a Laser Detector
Awacs4a.cdr
Time (days)
Prealarm Threshold
Analog
Reading
1.0% Alarm Selection 9
0.8% Alarm Selection 8
0.7% Alarm Selection 7
0.5% Alarm Selection 6
0.3% Alarm Selection 5
0.2% Alarm Selection 4
0.1% Alarm Selection 3
0.05% Alarm Selection 2
0.03% Alarm Selection 1
0.5% Pre-Alarm 9
0.4% Pre-Alarm 8
0.3% Pre-Alarm 7
0.2% Pre-Alarm 6
0.1% Pre-Alarm 5
0.05% Pre-Alarm 4
0.03% Pre-Alarm 3
0.02% Pre-Alarm 2
Self Adjust 1
1.0%
1.1%
0.9%
0.8%
0.7%
0.6%
0.5%
0.4%
0.3%
0.2%
0.1%
SAMPLE
SENSITIVITY
WINDOW
OBSCURATION (% PER FOOT)
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