C&K systems Intellisense FG-1025 Series, FG-1025Z, FG-1025, FG-1025R Technical Note

FG-1025 Family - Technical Note - 1

Technology Overview

FG-1025 Family

Glassbreak Detectors

2 - FG-1025 Family - Technical Note

Technical Note
FG-1025 Family
Glassbreak Detectors

Overview

This T echnical Note is intended to explain in detail the technical advancement of the new FG­1025 family of glassbreak detectors over the previous FG-730 family of products. Further, it is
intended to highlight the benefits of those enhancements to the customer . This Technical Note is
not confidential, and can therefore be provided to customers who have a technical interest in our
new FG-1025 family of glassbreak detectors.

Market Demand

The FlexGuard® FG-730 is the world’s best selling acoustic glassbreak detector, with well over
one million detectors installed worldwide. This popularity was achieved due to the detector’s
excellent glass break detection and false alarm immunity .

However , since the introduction of the FG-730, the market for glassbr eak detectors has changed.
The market now demands detectors without sensitivity adjustments for ease of installation, detec­tors which detect even the most minimal quiet breaks, and detectors with outstanding false alarm
immunity . Our new FG-1025 family meets these requirements.

Theory of Operation

Using a dual channel design, the FG-730 uses two technologies: listening for the acoustic sound
of glass breaking, and sensing the “flex” pressure generated when glass breaks. Signals are com­pared to set thresholds in the detector , and the detector alarms if the thr esholds are cr ossed. The
significant technical breakthrough of the FG-730 was sensing the flex, thus the name FlexGuard.

The FG-1025 family is based on the same flex/audio principle of dual technology sensing, but
with far more signal processing using an on-board micr ocontroller .

FlexGuard Signal Processing Design

C&K is a registered trademark of C&K Components, Inc. FlexGuard and IntelliSense are registered trademarks of IntelliSense Security Systems, Inc..

FG-1025

FG-1025ZFG-1025R

FG-1025 Family - Technical Note - 3

The FG-730 family of FlexGuard products are all analog devices. They route the signal from the
microphone through a series of discrete (individual) components on the circuit board. The signal
passes through circuitry gates which compare the signal to fixed threshold settings to see if the
amplitude (intensity) of the signal is greater than the threshold. The three threshold settings are:

 Flex level threshold: Does the signal exceed a fixed level for the flex?
 Audio level threshold: Does the signal exceed a fixed level for the audio?
 Time coincidence: Are the two thresholds both crossed within a time window of less than 200 millisec-

onds?
If these three set conditions occur, then the detector alarms.

FG-1025 Signal Processing Design

FG-1025 glassbreak processing is an order of magnitude beyond the FlexGuard. The heart of the
FG-1025 family is a Motorola 68HC05 micr ocontroller . Using four on-board A to D converters, the
microcontroller converts the analog signal into a digital datastream. Only the FG-1025 family uses
an advanced microcontroller, providing 2,1 12 bytes of ROM, 128 bytes of RAM, an internal clock,
and 21 lines of input/output all on-board.

The FG-1025 family is more computer than detector . It uses 1,019 lines of assembly language
computer code, each one a separate instruction for processing the digitized signal from the micro­phone. This software program is executed within the central processor unit (CPU). The custom
software is permanently burned into the microcontroller’s ROM at the Motorola factory, virtually
eliminating the possibility of memory loss. The FG-1025 family is the only glassbreak to use factory­installed masked ROM microcontrollers. Other detectors on the market use OTP (EPROM) alter­able memory , which can be subject to memory loss.

The FG-1025’s digitized signal is compared against eight thresholds:

 Flex level threshold: Does the signal exceed a level for the flex?
 Audio level threshold: Does the signal exceed a level for the audio?
 Time coincidence: Are the two thresholds both crossed within the time window?
 Flex/audio ratio: Is the ratio consistent with glass breaking?
 Attack threshold: Does the signal match an attack profile?
 Flex duration: Does the duration match a glass break profile?
 Audio duration: Does the duration match a glass break profile?
 Microphone overload: Does the signal represent a true glass break attack instead of microphone

overload?

If these eight conditions occur , then the detector alarms.

FG-1025

FG-1025R