Glossary : Access Control TermsThe following list provides definitions of standard terms used in the Access Control and Security industries.
- Access Card – An access control identification device assigned to an individual to give that individual access rights to an access control system. Typically, it is the size of a credit card. Each card has a unique identification code. That identification code is used by a controller to determine through which doors and at what times cardholders may be granted access to a secure area. See Key Tag.
- Access Code – Numeric or alphanumeric data which, when entered correctly, authorizes entry into a secure area.
- Access Control – A general term describing the control, management, and monitoring of the entrance and exit of people through secure areas.
- Access Control Card – An identification card with encoded information that, when presented to a card reader, identifies the cardholder to an access control system, allowing that system to determine the cardholder’s entrance and exit rights.
- Access Control Network – See Access Control System.
- Access Control System – An interconnected set of controllers, managing the entrance and exit of people through secure areas.
- Access Group – A superset of information including Timezones and secured Doors that is applied to cardholders. This information defines at what time-of-day and through which doors cardholders are granted access.
- Access Level – See Authorization Level.
- Access Mode – The condition in which all access parameters have been met, allowing an access control system to grant access.
- Access Point – The point of entry into a secure area. This point is typically managed by a controller using some combination of a card reader, an electric door lock, gate, turnstile, or similar device.
- Access Parameters – Programmed information that define the conditions that must be met to grant access. Such parameters may include access codes, access groups, authorization levels, or Timezones.
- Access Request – The act of presenting the information necessary to verify a person’s identity.
- Acquired Data – The data collected from an event that is used to make a decision, or is saved for future analysis.
- Active Card – A type of access control card that is dependent upon a card reader to provide the power necessary to allow the card to transmit its data.
- Actuator – A manually operated or automatically controlled switch or sensor which initiates a signal that can be processed by an access control system.
- Alarm Annunciation – The act of announcing that an alarm event has occurred. Annunciation can be done by an audible alarm, warning lamp or LED, or a pop-up window or message (in the case of alarm monitoring via computer software).
- Alarm Disable – The ability to physically or electronically make an alarm input unaccessible to an access control system.
- Alarm Enable – The ability to physically or electronically make an alarm input accessible to an access control system.
- Alarm Mask – The ability to selectively suppress the annunciation of certain alarm conditions, but allowing all other alarm conditions to properly report.
- Alarm Relay Output – a relay on the controller that changes its state upon command by the controller. Often the alarm relay output activates an audible alarm used to annunciate a door alarm.
- Alphanumeric – A text string made up of alphabetic and numeric characters.
- American Wire Gauge (AWG) – A standard for designating wire dimensions and specifications.
- AND Gate – A logic circuit that requires that all inputs must be in a high state (logic 1) to generate a high state output (logic 1).
- Annunciator – A device (such as a light or horn) that indicates an event has occurred.
- ANSI – An acronym for American National Standards Institute.
- Anti Passback (APB) – a method for providing one-card, one-way access into and then out of a secure area. It prevents someone from using a card to enter a secure area and then passing that card back to someone else to enter that same area.
- APB – See Anti Passback.
- Attended ID Station – A station where a security individual verifies the identity of someone seeking to enter a secure area.
- Audit Trail – A sequential record that accounts for all the activities of an access control system. This record allows for the analysis of events over a given time period.
- Authorization Level – A security rating that must be met before access to a secure area is granted.
- Authorized Person – A person who has been cleared to enter a secure area.
Automatic Time Switch – A timer that turns devices on or off at pre-set times.
- Auxiliary Code – A secondary code (often used on a temporary basis) that can be used for granting access or allowing access control system operation without revealing a primary code. See Primary Code.
- Auxiliary RTE – a second input source that informs the controller that someone has requested to exit from a secure area. See Request to Exit.
- AWG – See American Wire Gauge.
- Badge Reader – A reader used to read and interpret data encoded in an identification badge. See Card Reader.
- Badging Software – Security software that is capable of creating Photo Identification badges.
- Bar Code – A method of encoding information using lines and blank spaces of varying size and thickness to represent alphanumeric characters.
- Bar Code Card – An access control card with identification information encoded in Bar Code format.
- Bar Code Reader – A reader capable of reading and interpreting cards using bar codes to encode data.
- Barium Ferrite Card – An access control card with identification information encoded in the card via magnetic material embedded in the card.
- Barium Ferrite Reader – A reader capable of reading and interpreting cards using barium ferrite to encode data.
- Batch Programming – A method for processing data or performing tasks in which a number of commands are collected and then processed by a controller all at one time.
- Battery Backup – A secondary energy source used to power devices in the event the primary energy source fails. Battery Backup typically provides power for a short period of time, allowing for immediate action, system protection, and system shutdown before the battery reaches a drained state.
- Baud – The unit of data signal transmission speed, typically expressed in bits per second.
- Bell Transformer – A small transformer used to reduce power line voltage to the level required by low power devices (i.e. card readers)
- Binary Coded Decimal (BCD) – The decimal numbers 0 through 9 expressed in a 4-bit binary format.
- Biometrics – A general term for the verification of individuals using unique biological characteristics (i.e. fingerprints, hand geometry, voice analysis, the retinal pattern in the eye).
- Biometric Access Control – Access control where the identification process is made through biometric parameters. See Access Control, Biometrics.
- Bit – An abbreviation for “binary digit” in the binary number system. A bit will have the value of either 0 or 1.
- Break Before Make – A type of switch in which one set of contacts open before another set of contacts closes.
- Bus – 1) In power systems, a solid metal or uninsulated wire connector from which a universal type of power or ground connection is made. 2) In computer or data transmission systems, the principal channel through which all major sections communicate.
- Byte – A group of eight binary data bits.
- Card – An identification device assigned to an individual that identifies that individual. Typically, it is the size of a credit card. See Access Card, Key Tag.
- Card Access – A type of access control system using encoded cards and card readers to identify cardholders and determine if access may be granted. See Cardholder.
- Card Encoder – A device used to encode data onto an access card.
- Card Reader – A device that retrieves information stored on an access card and transmits that information to a controller.
- Cardholder – An individual who has been assigned an access control card or tag.
- Checksum – An additional set of information transferred with a computer program or a data stream that is used to verify the accuracy of the data just transfered.
- Chip-In-Card – See Smart Card.
- Circle of Protection – A security plan in which the items to be protected are surrounded by two or more protective zones of increasing size. For example, a bank vault may have the heavy vault door, followed by a controlled access door into the vault area, followed by the bank building with an alarm system.
- Circuit Breaker – A switch on an incoming power circuit that opens if abnormal circuit conditions arise (such as an overload or short circuit).
- COM Port – A hardware device that allows a computer to communicate with external devices.
- Conductor – A material that readily allows electricty to flow through it. Most metals are good conductors.
- Contact – A magnetically or electrically controlled connection point that opens or closes to interrupt or allow the flow of current.
- Contact Rating – The load rating of a switch, listed by maximum voltage and/or current accepted by the switch.
- Control Center – A central location in a secure area where access and alarm sub-systems are supervised and security personnel are located.
- Control Point – An exit or entry point such as a door, turnstile, or gate, where access is controlled.
- Controller – A microprocessor based circuit board that manages access to a secure area. The controller receives information that it uses to determine through which doors and at what times cardholders are granted access to secure areas. Based on that information, the controller can lock/unlock doors, sound alarms, and communicate status to a host computer.
- CSA – The CSA label on a product signifies that the product has met requirements set by CSA International, and that the product manufacturer is authorized to use the CSA symbol on their products.
- Cypher Lock – A digital push-button combination lock.
- Dedicated I/O Point – An input or output that is dedicated to a specific function. Often, dedicated input points can be assigned to initiate tasks such as an Auxiliary RTE, and a dedicated output point can be assigned to initiate tasks such as the annunciation of Door Forced or Door Held Open alarms.
- Dedicated Telephone Line – A telephone line directly connecting two points. Also Known As – Lease Line.
- Degausser – A device that creates a strong magnetic field that erases data from magnetically encoded media such as magnetic stripe cards.
- Degraded Mode – A mode of controller operation that provides a minimal authorization level in the event of controller failure.
- Distributed Access Control – Access control systems in which all control decisions are made at the local controllers, independent from a host computer. Local Controller events are uploaded to a host computer periodically for review and storage.
- Door – A generic term for a securable entry way. In many access control applications a “door” may actually be a gate, turnstile, elevator door, or similar device.
- Door Forced Alarm – An alarm generated when a door is forced open, opening the door switch contact.
- Door Held Open Alarm – An alarm generated when a door is held open beyond the a designated period of time (as programmed by access control software).
- Door Held Open Time – The amount of time from when a door is opened before an alarm is generated for the door being opened too long. This is often used to monitor if a door is being propped open following a valid access request.
- Door Switch – A switch that reflects the state of the door: if the door is open, the switch is open — if the door is closed, the switch is closed.
- Download – Sending information from a host computer to a peripheral device in an access control system.
- Duress – Forcing a person to provide access to a secure area against that person’s wishes.
- Duress Alarm – A device that generates a silent alarm signal in the event a person is experiencing Duress. This device may be a stand alone signalling device or it may be incorporated into a reader.
- Duress Code – An alphanumeric code which, when entered into an access control system, alerts the system to a Duress condition.
- Duty Cycle – The ration of system ON time to system OFF time.
- Earth Ground – An electrical connection point that brings all electrically neutral lines to the earth’s surface potential (essentially zero potential). A good earth ground helps to protect electrical devices from damage caused by transients such as power surges and lightening strikes, and drains electrical interference from data, communication, and power lines that support these electrical devices. See Ground.
- Electric Door Lock – A remotely operated electric locking device. See Electric Strike, Electromagnetic Lock.
- Electric Strike – An electric door lock that requires power to be applied to unlock a door.
- Electromagnetic – A general term referring to the electric and magnetic fields associated with the movement of electrons through conductors.
- Electromagnetic Interference (EMI) – Excess electromagnetic energy radiated by an electrical device that may affect the operation of other electrical devices.
- Electromagnetic Lock – An electric door lock that uses an electromagnet to hold a door closed. See Magnetic Lock.
- Embossed Card – An access control card that uses a raised pattern as a means of encoding data.
- EMI – See Electromagentic Interference
- Encoding – The process of writing data to a card.
- Entrance Delay – See Door Held Open Time.
- EPROM – An acronym for Erasable Programmable Read Only Memory.
- Event – An occurrence at a controller (such as unlocking a door, requesting to exit, forcing a door open) that generates a message stored by the controller.
- Exit Alarm – A device that indicates (either audibly or silently) that a secure door has been forced opened.
- Exit Lock – A push-bar door lock that spans the width of the door, used for emergency exit. An Exit Lock may be connected to an Exit Alarm.
- Exit Reader – A reader used to control exiting from a secure area.
- Exit Switch – A switch that is used to initiate a Request to Exit. See Request to Exit.
- Facility Code – Coded data in access control cards that identifies the location of the access control system.
Fail-Safe Door – A fail-safe door is one that if the power should fail at that door, the door will automatically unlock allowing exit and entrance. A fail-safe door ensures people will be able to exit a secure area through that door in the case of an emergency.
Fail-Safe Lockset – A lockset that is normally locked when the power is ON, and automatically unlocks when the power fails. See Fail-Safe Door.
Fail-Secure Door – A fail-secure door is one that if the power should fail at that door, the door will automatically lock and not allow entrance, but will continue to allow exit. A fail-secure door ensures a secure area remains secure regardless of the situation.
Fail-Secure Lockset – A lockset that is normally unlocked when the power is ON, and automatically locks when the power fails. See Fail-Secure Door.
False Alarm – An alarm signal generated without an existing alarm condition.
Fingerprint Pattern Area – The identifying characteristics of a fingerprint, consisting of the arches, loops, and whorls in the fingerprint.
Fingerprint Reader – A biometric reader that identifies a person based on the person’s fingerprint pattern.
- Gate – Typically, a door that is outdoors.
- General Protection Fault – An operating system fault that occurs whenever a program executes a command that the operating system considers dangerous to the operating system. When a GPF is generated, the program that generated the GPF is closed and control is returned to the operating system.
- Global Unlock – A normally-open input that, when closed, generates a signal that unlocks all doors in the access control system.
- Ground – 1) An electrical connection with a ground potential point. 2) An electrical connection to a circuit’s zero voltage reference point. See Earth Ground.
- Hand Geometry – A biometric access control technology that verifies a person’s identity by using the variations in hand size, finger length, and finger thickness.
- Historical Log – A chronological record of events.
- Host Computer – The central controlling computer from which access control software applications are run.
Identification – The act of recognizing one person as being unique from all other people.
Identification Card – A card that stores the information necessary to verify the identity of the cardholder.
Infrared Light – Light with a wavelength that is too low to be seen by the human eye.
Infrared Motion Sensor – A sensing unit that detects motion based on the disruption of infrared light waves.
Input – An electronic sensor on a controller that detects a change of state in a device outside the controller. See Normally-Closed, Normally-Open
Insertion Card – A card that must be inserted into a reader for the reader to retrieve the information stored on the card.
Intelligent Device – Any type of microprocessor-based input, output, or sensor device that has free-standing logic capability. These devices can be programmed with instructions that allow them to make their own decisions regarding granting access and sounding alarms. They also can communicate with a host computer to receive new instructions or to send event message logs.
- Jumper – A plugable, movable device that allows connections to be made between points on a circuit board.
- Key Tag – An access control identification device assigned to an individual to give that individual access rights to an access control system. Typically, the tag is attached to a key ring or similar device to provide quick, convenient access to the tag. Each tag has a unique identification code. That identification code is used by a controller to determine through which doors and at what times of day cardholders are granted access to a secure area. See Card
- Keyless Access Control – An access control system that controls access using something other than a key and a lock; typically some kind of reader and an electric door lock.
- Keypad – An alphanumeric grid which allows a user to enter an identification code.
- Keyswitch – A lockable switch operated by a key.
- Latching Relay – A relay that when set (either ON or OFF depending upon the relay configuration), locks into place until reset either manually or by a signal.
- LCD – The abbreviation for Liquid Crystal Display.
- LED – The abbreviation for Light Emitting Diode.
- Lease Line – See Dedicated Telephone Line.
- Line Drop – The drop in voltage along a power line caused by the resistance, reactance, and/or leakage in the line’s wires.
- Lock Relay Output – A relay on the controller that changes its state upon command by the controller, locking or unlocking a secure door.
- Logging – Creating and storing a permanent record of events that can be reviewed, printed, and analyzed.
- Magnetic Contact – A device that sends a signal when the magnetic field between two monitored points is broken.
- Magnetic Lock – A door lock made up of an electromagnet and a strike plate. The electromagnet is mounted in the door frame; the strike plate in the door. When power is applied to the electromagnet, the strength of the electromagnet keeps the door locked.
- Magnetic Stripe Card – An access control card with a strip of recordable magnetic material, on which data is encoded.
- Magnetic Stripe Reader – A reader capable of reading and interpreting cards using magnetic stripes to encode data.
- Master Code Card – An access control card that grants access and exit at every card reader on the system.
- Memory – The section of a host computer or a controller in which data and instructions are stored.
- Modem – A communication device that converts computer serial data to an analog format that can be transmitted and received via telephone.
- Network – 1) A series of controllers, all connected via a communications cable. 2) A group of computers, all connected via a communications cable.
- Normally-Closed – The state of an input device that continually keeps a circuit closed or complete until forced by an action or event to open that circuit. See Input.
- Normally-Open – The state of an input device that continually keeps a circuit open or incomplete until forced by an action or event to close that circuit. See Input.
- Online Help – A reference program within most software programs that provides basic descriptions and instructions on how to use that software program.
- OR Gate – A logic circuit that requires that any input must be in a high state (logic 1) to generate a high state output (logic 1).
- Output Relay – A device that changes its state upon receiving a signal from a controller. Typically the state change prompts an action outside of the controller such as activating or inactivating a device.
- Panic Bar – A quick release door lock allowing the door to be quickly opened in the case of an emergency situation. Also Known As – Crash Bar.
- Photo Badging – See Badging Software.
- Personal Identification Number (PIN) – A unique numerical code used to identify an individual.
- Piggybacking – 1) More than one individual entering a secure area using one access card. 2) Following an authorized person into a secure area. Also Known As – Tailgating. See Anti Passback.
- PIN – See Personal Identification Number.
- Primary Code – The main identification information provided by an individual to gain access to a secure area. See Auxiliary Code.
- Programmable Card – A card in which data may be encoded.
- Programmable Card Reader – A card reader in which instructions for granting or denying access may be programmed.
- Proximity – A method of reading a card or key tag without requiring any physical contact between the card/tag and the reading device. Click Here for a description of the operating principle behind proximity.
- Proximity Card – A card using proximity technology to store and transmit encoded data.
- Proximity Reader – A reader capable of reading and interpreting cards using radio frequency identification to encode data.
- Push-Button Lock – A lock that opens when a set of push-buttons are pressed in sequence or in unison.
- Radio Frequency Identification – A method of reading a card using radio frequency energy to transmit information from the card to a reader. See Proximity.
- RAM – See Random Access Memory.
Random Access Memory (RAM) – Randomly addressable, readable and writable memory (either volatile or nonvolatile) whose contents may be read or be altered at will.
- Reader – A device that “receives” an identification code from a card, key tag, magnetic stripe card, bar code card, or related item.
Relay – A device that is capable of opening a normally-closed circuit or closing a normally-open circuit. When the relay is not energized, the normally-closed circuit is complete and the normally-open circuit is open. When the relay is energized, it switches roles, opening the normally-closed circuit and closing the normally-open circuit. This dual nature of a relay allows for two types of applications: a device may be attached to the normally-closed circuit so that the device is always on until the relay energizes to turn it off, or a device may be attached to the normally-open circuit so that the device is always off until the relay energizes to turn it on.
Request to Exit (RTE) – A signal that informs the controller that someone has requested to exit from a secure area.
- REX – An acronym for Request to Exit. See Request to Exit.
Read Only Memory (ROM) – Nonvolatile memory whose contents are programmed into the ROM when the ROM is made, and therefore cannot be altered. ROM is typically used to store programs and fixed data sets.
- Real Time Command – A command that is executed immediately, with no time delay.
- RFID – See Radio Frequency Identification.
- ROM – See Read Only Memory.
- RS-232 – A serial communication protocol used for connecting data terminal devices. RS-232 is the most commonly used communication protocol.
- RS-485 – A serial communication protocol used for multi-drop communication applications. It is used for higher speed and longer distance communications.
- RTE – See Request to Exit.
- Secure Area – A designated area in which access into and out of is controlled and can be monitored.
- Secure Door – A door in which access through is controlled and can be monitored.
- Shielding – Providing electrical isolation for a circuit, component, or wire by enclosing or isolating the circuit, component, or wire with a metal enclosure, plate, or foil that blocks any interfering electrical field.
- Short Circuit – An unintentional connection that provides a low resistance path between two points in a circuit or between a point in a circuit and ground. A Short Circuit can drastically affect the operation of a circuit. If excessive current flow results from the Short Circuit, a device may be damaged or ruined.
- Shunt – 1) Deliberately shorting a portion of an electric circuit. 2) A device for shorting an electric circuit. See Short Circuit.
- Signature Verification – A biometric identification method using a person’s signature characteristics (writing speed, pen pressure, shape of loops, etc.) to identify that person.
- Spike – A voltage peak of high amplitude and short duration. See Transients.
- Smart Card – An identification card or access control card with a built-in integrated circuit chip. This gives the card microprocessor memory and intelligence to use for storing data. Also Known As – Chip-In-Card.
- Suppression – The addition of a device to an electrical circuit that minimizes or prevents transients from affecting the proper operation of that circuit.
- Switch – A device used to either connect or interrupt an electronic circuit.
Tailgating – 1) More than one individual entering a secure area using one access card. 2) Following an authorized person into a secure area. Also Known As – Piggybacking. See Anti Passback.
Telephone Entry – An access control system that allows users outside a secure area to use a telephone to contact someone inside the secure area and request access.
Timezone – A specified period of time in which access is allowed. A variety of timezones may be defined to accommodate the access needs of a variety of people.
Touchpad – See Keypad.
Transients – Electrical surges or spikes conducted through power or data lines. Transients are typically generated as electrical devices are turned on or off. See: Suppression.
Transorb – An electrical suppression device. See: Suppression.
Turnstile – An entryway that uses a mechanical device to restrict entry to one person at a time.
- UL – The UL label on a product signifies that the product has met the Underwriters Laboratories requirements and that the product manufacturer is authorized to use the UL symbol on their products.
- Upload – Sending information from a peripheral device to the host computer in an access control system.
- Verification – Identifying an individual based on some type of provided information. Verification may be done using by methods such as access cards, biometric information, PIN, etc.
- Voice Recognition System – An access control system that verifies a person’s identity by comparing previously stored voice recordings key words or phrases with the same key words or phrases spoken at the time access is requested.
- Wiegand Card – An access control card based on the Wiegand effect. Small bits of specially processed wire are embedded in the card in a pattern that uniquely identifies the card. This identification information can then be decoded by a Wiegand reader.
- Wiegand Compatible Devices – A propriatary coding format for information used by many of the suppliers of cards, key tags, proximity readers, magnetic stripe readers, bar code readers, and related items.
- Wiegand Effect – Electrical pulses generated when individual sections of specially processed magnetic wire is passed by a pickup coil. Each section of this magnetic wire has its own magnetic field. Depending upon the strength of the individual magnetic fields, the pickup coil either senses a strong field or overpowers a weak field, which generates an electrical pulse.
- Wiegand Reader – A reader capable of reading the information encoded on a Wiegand card.