AlarmsBC presents how control panels and the devices for an alarm system works

The most important feature in a control for home alarm use is the maximum number of zones that the control can support (some panels can support over 100). Remember that a zone can be a single point of protection, or you can combine multiple points into a single zone. For example, if you have 4 windows in your bedroom you could put each window a separate zone or you could combine the all the windows into 1 zone. Zoning becomes important if you start getting false alarms. If each window has its own zone, you will know exactly where the problem is. If you have 6 windows on 1 zone it will take more time to find the problem.

Additional zones will increases the price, but it may be wise to take some steps during the installation to enable you to add zones in the future without major costs. First make sure that the installer runs separate wires from each device to the control panel (home run wiring), so that re-wiring to the devices will not be needed, second get a control which can be expanded to include the total number of zones you will need in the future. This way, adding zones is simply a matter of adding expander boards and re-connecting wires at the control.

Today's control allow many levels of arming. The basic ones are AWAY and HOME DELAY. AWAY arms all perimeter and interior devices and provides an exit/entry delay. It is used when everyone is leaving and no one is home. HOME and HOME DELAY arms only perimeter devices and provides exit/entry delay. It is used when you are arming the system and inside the home.

Sometimes you may want to disconnect or bypass one or more zones. If you are having a door or window replaced, or a motion sensor has been damaged or causing false alarms, you may have to bypass the protection until your security company can reinstall protection or replace the defective device.

Forced arming is the arming of a system with one or more zones in trouble. It is similar to automatic bypass with one exception. On some systems, if the troubled zone returns to normal after the system is force armed it can becomes active in the system.. This is helpful if the zone was a motion detector that was not reset when you were arming the system but does reset a minute later.

Monitoring is the connection of your security system to a remote Central Station. When your system trips the signal is sent via the phone lines to the Central Station where the operator will verify the alarm and call the appropriate authorities. In addition to calling the police or fire departments, they will also notify persons on your call list (neighbour or family). The monitoring company will also establish a "Pass-code or Code word" with you that will enable them to verify that the person they are speaking with is the authorized person. Any other code word than the one authorized, will tell the central station that you are "under duress" and the police will be notified of the situation.

Many local Police departments are starting to fine homeowners and businesses for false alarms. To reduce the chance of a false alarm, use dual-tech sensors in the installation of your system, or upgrade to dual-tech sensors if you are getting false alarms on your current motion sensors. Most false alarms are caused by improper operation or improper maintenance of the system. You must make sure that anyone operating the system is familiar with its operation. Having the central station verify an alarm can also help reduce false alarms.

KEYPADS

The display on your Keypad consist of either LED's or an Alphanumeric display. The Alpha displays are more expensive then the LED display, but give you an English language display of the violated and trouble zones.They are much easier for the average homeowner.

The keypad is like your keyboard and monitor of your computer. Trough your keypad you arm , disarm, bypass zones, change codes etc.... The display will let you know if the system is armed, or not, that zone was tripped in case of alarm etc.

HOW THE GLASS BREAK DETECTORS WORKS

Glass break detector is limited by how well it hears all sounds and by how smart it is in reacting to the one sound that poses a threat. Sound is captured with an advanced microphone system able to capture sound far beyond the range of human hearing, at low volume and up to 25 ft. away.
Once captured, sound is digitally analyzed in remarkable detail in just a fraction of a second. Excellent RF immunity along with protection from static discharge and transients add to reliability.

Advanced sound analysis technology can detect all of the common types of breaking glass with ease: plate, laminated, wired or tempered. In addition to glass type, it also accommodates changes in pane size, glass thickness and room acoustics.
This method of detecting a burglar is often used when there are pets in the home which will trip motion detectors.
They allow you to have perimeter protection of the building with the freedom to walk around inside without setting off the alarm.
They also offer an earlier protection because they trip the alarm BEFORE the burglar enters the premises; thus they are often referred to as "pre-entry" alarms.

Passive Infrared Detectors:

A Passive Infrared Detector operates by detecting the change in energy that occurs when a body of one temperature passes by a background of another temperature within the detector's field of view.
The device consists of a mirror or lens that can focus the energy, a thermal sensor to detect the energy, and associated electronics to analyze the information. The area that a unit can protect is usually given in feet representing the length and width of it pattern, such as 35 X 35 feet.

Special signal processing techniques enable the detector to determine whether a signal is caused by a person, or by some other, false alarm source. Interchangeable optics allow the protection area to be customized to meet the needs of the specific application.

The thermal sensor used in today's PIRs is actually two (dual) or four sensors (quad) in a single unit. The two-element device, which is commonly called a Dual PIR (not to be confused with dual-tech which is a combination PIR and microwave sensor-both technologies have to trip before the unit goes into alarm)., divides each zone into two distinct, side-by-side detection areas. A person moving will first activate one of these sensors and then the other. This allows the PIR to reject alarms that originate from heated surfaces or even RF interference, since both of these are detected simultaneously by both elements.

A four-element device, which is commonly called a Quad PIR, further divides the zones into an upper and lower area. This allows the unit to compare the signals received, further reducing the possibility of false alarms.

PIRs incorporate additional features that help to minimize false alarms, such as white-light filters and pulse-count circuits. The white-light filters, for example, prevent the device from falsing (false alarming) when exposed to a source of direct light where the pulse-count circuit tells the unit not to activate unless it detects motion multiple times in rapid succession.

Proper PIR placement is essential for good protection and false alarm reduction. The following guidelines should be considered when using PIR detectors:
Match the PIR to the area. Using a unit that has a 100-foot range in a twenty foot room can cause false alarms.
Do not mount the unit facing windows or any source of rapidly changing heat or cold air.
Seal all openings into the unit to prevent insects and drafts from entering the unit and causing false alarms.
Mount the unit so that an intruder will have to walk across the detection pattern, rather than towards the detector.

Photoelectric Detectors:: Photoelectric beam detectors consist basically of a light transmitter and a separate receiver. The transmitter emits an invisible infrared beam to the receiver. If the beam is broken, the receiver signals an alarm.

WIRELESS SYSTEMS

Supervised transmitters

In the past wireless systems were simple radio frequency (RF) transmitters , similar to garage door openers. They were frequently unreliable , had limited range , short battery life , and were "unsupervised" , so if the transmitter failed , the system simply failed to respond. Also , the alarm system could be armed even if a door or a window , as the transmitter only signaled when an opening actually occurred.

Today , the newest RF transmitters are very much improved . They are much smaller , have a much greater range , and battery life 3-5 years. The transmitters are fully supervised , so if a transmitter fail to send a periodic "check-in" signal , the control panel will alert the central station. The transmitter is also monitor their battery , and will transmit a "low battery" alert weeks before their performance is affected . The alarm panel also monitor the last status of all devices , so an open door will report "open" until the panel receive a "closed" signal from the transmitter .
Alarm transmitters are available as self-contained devices , or with contacts , PIR , smoke detector , glass break detector , built-in . They are more expensive than hardwired devices but installation cost is considerably less .

Wireless Controls

Some manufacturers also offer keypads that are wireless . These can be carried around , or mounted where wiring is difficult . Some of these keypads have a number-pad included for entering a code , while others have buttons for "arm", "disarm" and "emergency" . Obviously , your security is severely compromised if these are left available to an intruder . One manufacturer has a two way wireless keypad that signals whether the system is armed or not before you approach the door . It can also tell you if the alarm was tripped since the last exit .

Integrating with Hardwire Systems

Some hardwired controls can have wireless transmitters adapted to them . If you are considering such an approach , be sure the control panel actually supervises the alarm receiver , so the status of transmitters is always known .
Systems with integrated wireless are usually more reliable and easier to install and maintain . Since most homes or commercials locations will ideally be served by a combination of wired and wireless sensors , a control panel that offers both would be preferred .

from HOME INTELLIGENCE MAGAZINE

� Copyright 1997- 2010
Information in this document is subject to change without notice.
Other products and companies referred to herein are trademarks or registered trademarks of their respective companies or mark holders.
UPDATE 01-Jan-2010
MMC&S Inc.