Glossary
Any sensor in a system that cannot be disarmed or bypassed, such as fire detectors.
Access Code
A numeric combination that grants access to the system.
Access Control
Computerized and mechanical processes for limiting access to resources based on users' identities and predefined roles. May be integrated with intrusion and fire detection and access control.
Alarm
A device for signaling an emergency.
Antenna
A transmitting device that converts radio frequency energy into an electromagnetic field that travels through space, or a receiving device that converts an electromagnetic field in space into RF energy that can travel via a wire or cable.
Anti-Passback
An access control feature that prevents system users from giving their access codes or cards to someone else. A user code must be used to enter and then to exit before it can be used to enter again. Similarly, to prevent the same PIN from being used by several persons, a time delay can be programmed so the PIN won't work again until the time delay is complete.
Arm
To activate a security system so that its sensors detect changes of state and report those changes to a control panel.
Arming Levels
A set of instructions that determines which sensors are activated and which are not. All sensors would be armed when you are away from home, for example, but interior sensors would not be armed when you are home and moving around the house.
Asset Tracking
Software that enables control of physical assets, such as laptop computers and other high-value equipment. The system ensures that the cardholder requesting access is authorized to take assets through designated alarm points.
Auxiliary/Medical Alarm
An alarm signaling the need for medical personnel.
Backward Compatible
Equipment that can operate with earlier and future versions of software. Backward-compatible products enable innovation without additional equipment upgrade costs.
Band
The frequencies used for a specific class of RF wireless communications system.
Bandwidth
The amount of radio spectrum used by a communications system. Both the transmitter and the receiver have a measurable bandwidth (measured in Hertz). A receiver's bandwidth must be as large or larger than the transmitters bandwidth, so that all of the signal is received.
Biometrics
Usually used as part of an access control system, biometrics identify individuals on the basis of fingerprints, iris patters, or other identifying traits.
Buddy System
An arrangement between two neighboring systems in which a cut phone line in one system activates an alarm via the neighboring system.
Bypass
An instruction to a security system not to arm a specific sensor.
Carbon Monoxide
A colorless, odorless and highly toxic gas produced during combustion by furnaces, water heaters and other home appliances. According to the National Safety Council and the Centers for Disease Control, CO kills between 500 and 1,000 persons each year in their homes; 5,000 people in the United States are treated in emergency rooms for carbon monoxide poisoning.
CCTV
Closed-Circuit Television. The use of cameras for surveillance. Images may be viewed on a monitor, via the Internet, or digitally recorded for later viewing and submission as evidence.
Central Monitoring Station
An agency that receives alarms from subscribers' security systems and requests the dispatch of fire, police, or medical authorities.
Control Panel (system controller)
The "brains" of the security system. Receives transmissions from sensors and communicates data to the central monitoring station.
Decibel
A relative measure of the difference between the power level of two signals. The signal strength of a door/window sensor in a residential system might range from .1mW for a close-in transmitter to .00000000001mW for a transmitter in a remote closet.
Delay
The time allotted the system user to exit the premises after turning the system on without causing an alarm (exit delay); the time allotted the system user to enter the premises and turn off the system without causes a false alarm (entry delay).
Disarm
To turn the system or a sensor off.
Diversity
To eliminate the effects of multipath distortion, diversity communications systems use redundant signal paths between the transmitter and receiver.
Door/Window Sensor
A device for detecting the opening of a door or window and for sending a signal to the control panel indicating the change of state.
DVMR
Digital Video Multplexer/Recorder. A device that receives images from several CCTV cameras at once and enables the images to be viewed on a monitor or recorded.
Electric Strike
Electronic device for locking and unlocking doors in response to signals from an access control system.
Electronic Access Control
Controlling entry into a physical area by means of a controller and electronic components including locks, readers, sensors, buttons and more. Electronic access control specifies who can go where and when.
Ethernet
A way of networking multiple devices into one system, enabling a security system to be controlled from different access points within the network.
Event Log
A record of actions performed and recorded by a security or access control system.
False Alarm
Any alarm sounded when there is no cause for alarm.
Fire Alarm
A signal transmitted by heat or smoke detectors.
Free Air Range
The line-of-sight unobstructed communications distance of a transmitter/receiver system.
Glassbreak Sensor
A device that detects frequencies that accompany the breaking of glass.
Handheld Panic Button
A transmitting device for activating a panic alarm.
Heat Sensor
A device that detects heat or a rapid change in temperature which occurs in the presence of fire.
Home Automation
The use of devices to automatically regulate or perform functions commonly associated with the home.
Homeland Security
Security projects and technologies that monitor:
• borders, transportation, and seaports
• infrastructure such as communications systems and power grids
• chemical and biological threats
• needs of police, fire, and emergency medical personnel
Interference
RF energy in the receiver's band that is not made by a system transmitter; reduces the communications range of a transmitter-receiver system.
Interior Sensors
Devices that register changes of state of interior spaces or doors.
Intrusion Alarm
a signal transmitted by sensors that detect intrusion. Door/Window sensors and motion sensors most commonly send intrusion alarm signals.
Joystick
A controller for moving a pan/tilt/zoom camera up, down, left or right.
Local Area Network (LAN)
A connected system of cameras, recorders, and other security systems that communicate with each other and can be controlled from different access points in the system.
Message or Data
The information sent by a communications system.
Module
In-home automation, a device for interfacing controllers with security devices, lamps, appliances and other devices. Each module has an address which may be unique or may be the same as other modules.
Monitoring Service
See Central Monitoring Station
Motion Detector
Passive InfraRed: PIR: An intrusion detector designed to register changes of temperature, which occur when an intruder enters a protected space.
Narrow Band
Refers to a communications system that transmits and receives using only as much radio spectrum as is needed to pass the message data rate.
No Delay
With remote arming and disarming capabilities the system user can approach the premises and before entering disarm the system with no delay. This eliminates the feeling of being rushed to turn off the system to prevent a false alarm after entering a delay door.
Panic Button
A remote control device or a button on a control panel that sends an alarm signal without requiring the use of an access code.
Panic Pendant
A portable device that sends a wireless panel signal to the control panel. They can be worn around the neck with a neck strap, clipped to a belt, or placed in wall-mounted holders.
Radio Frequency
The alternating voltage and magnetic fields in a radio signal. Frequency is measured in cycles per second, which is usually referred to as a Hertz after the man who discovered them. A megaHertz (MHz) is a frequency of 1 million cycles per second.
Radio Spectrum
The frequency range of electromagnetic radiation used for all RF wireless communications systems.
Receiver sensitivity
The ability of the receiver to hear the transmitter's signal.
Receiver
The RF analog and logic components in the security alarm panel that processes the signals received by the antenna and reconstructs the digital message of the transmitter.
Sensor
A device that detects a change from one state to another. For example, a door/window sensor detects the change in a circuit from a normally closed state to an opened state.
Silent Alarm
An alarm received by a central station operator which does not activate a local alarm sound.
Smoke Sensor
A device of either photoelectric or ionization design which detects the presence of smoke and sends a fire alarm signal to the control panel.
Spatial Diversity
Using two or more antennas (on either the transmitter or the receiver) where the two antennas are switched. Having antennas with unique locations provides independent signal paths through space and thereby significant fade resistance.
Supervision
The use of a special signal sent automatically from the transmitter to the receiver to inform the receiver that the transmitter is operating properly.
Transmitter Power
The signal intensity of the transmitter. The higher the power radiated by the transmitter's antenna the greater the reliability of the communications system.
Transmitter
The circuit that includes logic that generates a baseband message describing the status of the inputs to the transmitter, a radio frequency oscillator that generates the carrier frequency, modulation method to impose the message onto the carrier frequency, and an antenna to radiate the signal.
Two-Way Voice
A technology for allowing a central station operator to hear what transpires after an alarm is activated and to talk to persons on the scene.
User ID
A unique identification code that enables access. Usually used in conjunction with a password.
Video Motion Detection
Detection and triggering of video recording by a camera.
Wave Length
The distance that the radio wave travels in one cycle of the transmitters frequency. At 300 MHz a wavelength is about 30 inches and at 900 MHz a wavelength is about 8 inches.
Wireless Keychain Touchpad
A system-controlling device designed to fit in a pocket or purse.
Zone
Sensor or group of sensors having a single numerical identity.
