Security and protection terms

Alarm terms 
A simplified guide to the security industry...
There are hundreds of different types of security systems and components on the market today. Furthermore, there are many terms and expressions used to describe the security system components, their operation and features. As the security industry grows, it is evident that there is confusion regarding security systems among police departments, the insurance industry, the building trades, property management, engineers, architects and the general public.

The purpose of this guide is to standardize commonly used terms and expressions of the security industry into simpler terms.

To jump directly to an area of interest simply select a letter of alphabet from below :

ALARM SYSTEM: A group of components including INPUT DEVICES, a CONTROL PANEL and OUTPUT DEVICES installed so as to minimize loss from burglary, vandalism, fire, etc.

ARM: To turn on the ALARM SYSTEM, so that when an intrusion occurs, an OUTPUT DEVICE is activated.

BATTERY: This is a standby source of power for the ALARM SYSTEM in the event of a power failure. The BATTERY is usually rechargeable once normal power is restored.

BYPASS: To temporarily deactivate a portion of the INPUT DEVICES, so as not to trigger the ALARM SYSTEM while ARMED. This is usually done in homes so that MOTION SENSORS can be shut off to allow movement by the occupants, while the system is ARMED.

CELLULAR BACK-UP: An OUTPUT DEVICE which is triggered by the loss (cutting) of the protected premises telephone line. Upon activation, the CELLULAR BACK-UP transmits the alarm signal to the MONITORING STATION via the cellular telephone network. This is used as an alternative to DIRECT LINES.

CENTRAL STATION: A facility to provide monitoring services of remote customers premises where ALARM SYSTEMS are installed which automatically signal in the event of an intrusion, fire or other incident. All activities are recorded and acted upon by trained operators.

CONTROL PANEL: Also known as the "Processor" or "CPU", this is the electronic brains of the security system. All of the INPUT DEVICES are connected here for processing. Upon receipt of an intrusion signal from an INPUT DEVICE, the CONTROL PANEL will process the signal and in turn trigger an OUTPUT DEVICE which is connected to the ALARM SYSTEM. The CONTROL PANEL is made up of various circuitry boards which are mounted inside a protective metal housing. The CONTROL PANEL box is large enough to accommodate a back-up BATTERY, as well as a number of wires that have been run from various INPUT and OUTPUT DEVICES. The CONTROL PANEL comes in different ZONE configurations, usually 6, 8, 16 and more ZONES depending on the number of INPUT DEVICES. Ideally, it is best to have one ZONE per INPUT DEVICE.

DELAY ZONE: Any ZONE that after it has been violated or opened, waits a predetermined amount of time before triggering an alarm condition. This usually refers to the door that is used for authorized entry into the premises by the user. The delay allows time to DISARM before the alarm is triggered.

DIGITAL COMMUNICATOR: An OUTPUT DEVICE, which, upon activation from the CONTROL PANEL, transmits a signal to the MONITORING STATION via the existing subscribers" telephone line. The DIGITAL COMMUNICATOR is a popular method of transmitting intrusion signals due to the ease of installation and the low cost of not requiring a special DIRECT LINE telephone circuit. A drawback of this is that if the telephone line is cut at the subscribers" premises, no signal will be sent to the MONITORING STATION.

DISARM: To turn off or de-active the ALARM SYSTEM.

DUALTEC MOTION SENSOR: A MOTION SENSOR which utilizes more than one sensing technology to initiate an alarm condition. A usual combination is a Passive Infrared (PIR) combined with Microwave or an UltraSonic detector. These INPUT DEVICES are usually more stable and less likely to encounter a FALSE ALARM CONDITION.

FALSE ALARM CONDITION: A situation where an alarm signal is triggered without any intrusion attempt. Some causes of this are user error, telephone line trouble and equipment malfunction. User error accounts for over 80% of all false alarms.

FALSE DISPATCH: A situation where the police are dispatched to a premises when there is no actual alarm. Causes are as in FALSE ALARM CONDITION. FALSE DISPATCHES cost the police time and money. It is vital that installers train all users of a system on proper operation of the system, in order to avoid false dispatches.

GLASS BREAKAGE DETECTOR: An INPUT DEVICE which is triggered by the sound of breaking glass.

HEAT DETECTOR: An INPUT DEVICE used for fire detection, which is triggered by a rapid rate of temperature rise and/or the temperature reaching a fixed high point. Usual fixed temperature points are 135, 180 and 200 degrees F.

HOLD-UP BUTTON: A manually activated button which, when pressed, will send a silent signal to the MONITORING STATION. Used mostly in stores for use in a hold-up situation.

PERSONAL ID: A number, unique to each alarm user, which identifies that user over the telephone to the MONITORING STATION. It is also know as a PIN (personal identification number) CODE. This ID# is most often used when the user accidentally triggers the ALARM SYSTEM.


KEYPAD: A keyboard type device used for entering a numerical code to ARM or DISARM the ALARM SYSTEM. Some KEYPADS have the capability to have multiple numeric codes to accommodate several users.

KEY SERVICE: A service provided by the Operating Alarm Company where keys are held to permit immediate access to the protected premises.

LOCAL ALARM SYSTEM: An ALARM SYSTEM which, when triggered, will only trip a SIREN or similar device on its own premises. It does not transmit a signal to a MONITORING STATION and usually will not be responded to by the police. In some municipalities, local systems violate noise regulations.

MAGNETIC CONTACTS: This is the perimeter protection for the premises. The magnetic contact is usually installed in exterior opening doors and windows that are reachable from the ground (or from another part of a building which is accessible from the ground - such as a garage). The contacts operate on the principle that when the door or window moves more that 1/2" from the frame, the magnetic field on the switch is removed and this breaks the alarm circuit (or zone) which trips off the system. Once tripped, the alarm signal cannot be stopped by just closing the door or window. Magnetic contacts are popular and widely used because they detect an intruder before he enters the protected premises. A disadvantage is that the contact can be compromised if the intruder enters without opening the door or window, by breaking the glass.

MONITORED ALARM SYSTEM: An ALARM SYSTEM which, when triggered, transmits a signal or message to a MONITORING STATION.

MONITORING STATION: This facility is the same as the CENTRAL STATION, however, there is no requirement for guards to be on duty.

MOTION SENSORS: An INPUT DEVICE, the motion sensor works on the principle of sensing infrared energy (heat) emitting from an intruder"s body moving through a protected area. The MOTION SENSOR is commonly referred to as a PIR, which stands for passive Infrared. The sensor usually covers a 40" x 40" open area at a 90 degree angle. The sensor is more sensitive to movement perpendicular to it rather than to and from it. The unit should be installed in a location where there will be a "cross catch" across its pattern. The Motion Sensor will not detect intruders through walls, glass, furniture or any other solid objects. If the customer has pets, a special PET ALLEY LENS or PET IMMUNE MOTION SENSOR is utilized. The Pet Alley Lens mounts at about light switch height and creates a blind spot to allow pets to wander around underneath whereas a Pet Immune Motion Sensor knows the difference between an intruder and a pet. If the premise has more than one Pet, ensure that the Pet Immune Sensor installed is capable of handling more than one pet.

OPENINGS & CLOSINGS: This is an additional service provided for MONITORED ALARMS. Each time the ALARM SYSTEM is ARMED and DISARMED, the MONITORING STATION receives a separate signal as to the time of day and the person who does it. The information is recorded and, if the system is not ARMED at the regular closing time, the client is notified. If the system is DISARMED at an irregular time (i.e. middle of the night), the client and/or police is notified.

OUTPUT DEVICE: Devices which alert other people in the event of an intrusion or alarm condition. These include SIRENS, bells, DIGITAL COMMUNICATORS, STROBE LIGHTS and buzzers.

PHOTOELECTRIC BEAMS: This is an INPUT DEVICE that is made up of a two part set of detectors that emit a fine invisible beam between them. The unit is triggered it the beam is interrupted by an intruder passing through it.


SIREN: An audible OUTPUT DEVICE installed at the subscribers" premises. The SIREN sounds a high pitched warbling tone, similar to a police car. Its purpose is to deter the intruder and draw attention to the premises. Bells can also be used as an alternative.

SMOKE DETECTOR: An INPUT DEVICE used for fire detection which is triggered by smoke. The two main types of SMOKE DETECTORS are photoelectric and ionization.

STROBE LIGHT: An OUTPUT DEVICE that is bright, flashing light, The unit is mounted on the exterior of the premises to help direct authorities to the location.

SUPERVISED: Normally refers to wiring which, when cut or tampered with, will notify someone of the tampering.

WIRELESS ALARM SYSTEMS: An ALARM SYSTEM that uses INPUT DEVICES that report to the CONTROL PANEL without the use of wires. The INPUT DEVICES use radio frequency transmitters to relay signals to the CONTROL PANEL.

ZONE: An ALARM SYSTEM with many INPUT DEVICES is often separated into a number of areas called ZONES. Each Zone is numbered and has a corresponding Light (LED) which, when illuminated, means that ZONE is insecure (i.e. that particular door or window is open).