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NFS2-640/E Programming Manual —
P/N 52742:L2 7/17/14
95
Appendix C: Intelligent Sensing Applications
C.1 Overview
“Intelligent Sensing” is a set of software algorithms that provide the
NF2S-640
with industry-
leading smoke detection capability. You can program Intelligent Sensing functions on a global or
on a per-detector basis.
Intelligent Sensing topics covered in this appendix:
C.2 Features
Intelligent Sensing Applications features include the following:
• Drift Compensation and Smoothing
• Maintenance Warnings - Three Levels
• Self-optimizing Pre-Alarm
• Detector Sensitivity
• Cooperative Multi-Detector Sensing
C.2.1 Drift Compensation and Smoothing
Drift compensation uses algorithms (U.S. patent pending) that identify and compensate for long-
term changes in the analog readings from each smoke detector. (Typically, dirt and dust
accumulation inside the smoke chamber causes long-term changes in detector readings.) Drift
compensation does the following:
• Allows a detector to retain its original ability to detect actual smoke, and resist false alarms,
even as dirt and dust accumulates.
• Reduces maintenance requirements by allowing the control panel to automatically perform
the periodic sensitivity measurements required by NFPA Standard.
The software also provides smoothing filters to remove transient noise signals, usually caused by
electrical interference. Different smoothing algorithms are used, depending on the sensitivity
selection of each detector. Refer to “Detector Sensitivity Settings” on page 101 for more
information on detector sensitivity levels.
Topic
Page
Intelligent Sensing Applications features
– Descriptions of features,
such as Drift Compensation, Sensitivity Adjust, programmable on a per-
detector basis.
Pre-Alarm
– Alert and Action settings, programming (global settings).
Detector Sensitivity Settings
– Pre-Alarm and Alarm sensitivity settings
for photo, ion, laser, and multisensor detectors programmable on a per-
detector basis.
Detector Maintenance Features
– Instructions for viewing and printing
detector maintenance information.