RFID (Radio Frequency Identification ) SYSTEM

Low-frequency:

From 30 kHz to 300 kHz. Low-frequency tags typical operate at 125 kHz or 134 kHz. The main disadvantages of low-frequency tags are they have to be read from within three feet and the rate of data transfer is slow. But they are less subject to interference than UHF tags.


Ultra-high frequency:

From 300 MHz to 3 GHz. Typically, RFID tags that operate between 866 MHz to 960 MHz. They can send information faster and farther than high- and low-frequency tags. But radio waves don’t pass through items with high water content, such as fruit, at these frequencies.


Reader:

A device used to communicate with RFID tags. The reader has one or more antennas, which emit radio waves and receive signals back from the tag. The reader is also sometimes called an interrogator because it "interrogates" the tag.


Antenna:

The tag antenna is the conductive element that enables the tag to send and receive data. Passive, low- (135 kHz) and high-frequency (13.56 MHz) tags usually have a coiled antenna that couples with the coiled antenna of the reader to form a magnetic field. UHF tag antennas can be a variety of shapes. Readers also have antennas which are used to emit radio waves. The RF energy from the reader antenna is "harvested" by the antenna and used to power up the microchip, which then changes the electrical load on the antenna to reflect back its own signals.



High-frequency:

This is generally considered to be from 3 MHz to 30 MHz. HF RFID tags typically operate at 13.56 MHz. They can be read from less than 3 feet away and transmit data faster than low-frequency tags. But they consume more power than low-frequency tags.


RFID tag:

A microchip attached to an antenna that is packaged in a way that it can be applied to an object. The tag picks up signals from and sends signals to a reader. The tag contains a unique serial number, but may have other information, such as a customers' account number. Tags come in many forms, such smart labels that can have a barcode printed on it, or the tag can simply be mounted inside a carton or embedded in plastic. RFID tags can be active, passive or semi-passive.


Transponder:

A radio transmitter-receiver that is activated when it receives a predetermined signal. RFID transponders come in many forms, including smart labels, simple tags, smart cards(Smart cards:A credit card or other kind of card with an embedded microchip. When the card uses RFID technology to send and receive data it is called a contactless smart card. ) and keychain fobs. RFID tags are sometimes referred to as transponders.

The transponders can be read(Read:The process of retrieving data stored on an RFID tag by sending radio waves to the tag and converting the waves the tag sends back into data.)/write (depending on the chip used), which allows information about the contents of the crate or pallet to be written to the transponder. Lindström says the transponders can cost less than $1, depending on the volume, form factor, chip and other factors. Since the containers might go through seven or more turns a year and last five year or more, the price per use will likely be no more than a few pennies. Form factor: The packaging a transponder can be put in. These include thermal transfer labels, plastic cards, key fobs and so on.


Read range:

The distance from which a reader can communicate with a tag. Active tags have a longer read range than passive tags because they use their own power source (usually a battery) to transmit signals to the reader. With passive tags, the read range is influenced by frequency, reader output power, antenna design, and method of powering up the tag. Low-frequency tags use inductive coupling, which requires the tag to be within a few feet of the reader.


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Active tag:

An RFID tag that has a transmitter to send back information, rather than reflecting back a signal from the reader, as a passive tag does. Most active tags use a battery to transmit a signal to a reader. However, some tags can gather energy from other sources. Active tags can be read from 300 feet (100 meters) or more, but they're expensive (typically more than US$20 each). They're used for tracking expensive items over long ranges. For instance, the U.S. military uses active tags to track containers of supplies arriving in ports.


Passive tag:

An RFID tag without its own power source and transmitter. When radio waves from the reader reach the chip’s antenna, the energy is converted by the antenna into electricity that can power up the microchip in the tag. The tag is able to send back information stored on the chip. Today, simple passive tags cost from U.S. 20 cents to several dollars, depending on the amount of memory on the tag, packaging and other features.



Automatic Identification:

A broad term that covers methods of collecting data and entering it directly into computer systems without human involvement. Technologies normally considered part of auto-ID include bar codes, biometrics, RFID and voice recognition.

Automatic identification and data capture:

A broad term that covers methods of identifying objects, capturing information about them and entering it directly into computer systems without human involvement. Technologies normally considered part of auto-ID include bar codes, biometrics, RFID and voice recognition.


Bar code:

A standard method of identifying the manufacturer and product category of a particular item. The bar code was adopted in the 1970s because the bars were easier for machines to read than optical characters. The main drawbacks of bar codes main are they don’t, in most cases, identify unique items and scanners have to have line of sight to read them.

Capacitor:

An electric circuit element used to store a charge temporarily. A capacitor usually consists of two metallic plates separated and insulated from each other by a dielectric substance.

Chipless RFID tag:

An RFID tag that doesn't depend on a silicon microchip. Some chipless tags use plastic or conductive polymers instead of silicon-based microchips. Other chipless tags use materials that reflect back a portion of the radio waves beamed at them. A computer takes a snapshot of the waves beamed back and uses it like a fingerprint to identify the object with the tag. Companies are experimenting with embedding RF reflecting fibers in paper to prevent unauthorized photocopying of certain documents. Chipless tags that use embedded fibers have one drawback for supply chain uses—only one tag can be read at a time.


Data carrier:

A medium that holds machine-readable data. Bar codes and RFID tags are types of data carriers. The term is also applied to a carrier frequency used to transmit data.


Data field:

An area of memory in RFID microchips that is assigned to a particular type of information. Data fields may be protected (see below) or they may be written over, so a data field might contain information about where an item should be sent. When the destination changes, the new information is written to the data field.

Data field protection:

The ability to prevent data stored in a specific area of memory of an RFID microchip from being overwritten. Companies might want to protect the data field that stores an Electronic Product Code(A serial, created by the Auto-ID Center, which will complement barcodes. The EPC has digits to identify the manufacturer, product category and the individual item.), which doesn't change during the life of the product it's associated with


Data transfer rate:

The number of characters that can be transferred from an RFID tag to a reader within a given time. Baud rates are also used to quantify how fast readers can read the information on the RFID tag. This differs from read rate, which refers to how many tags can be read within a given period of time.

Edge server:

A computer for running middleware or applications that is close to the edge of the network, where the digital world meets the real world. Edge servers are put in warehouses, distribution centers and factories, as opposed to corporate headquarters.

Middleware:

In the RFID world, this term is generally used to refer to software that resides on a server between readers and enterprise applications. The middleware is used to filter data and pass on only useful information to enterprise applications. Some middleware can also be used to manage readers on a network.

Electrically Erasable Programmable Read-Only Memory(EEPROM):

A method of storing data on microchips. Usually bytes can be erased and reprogrammed individually. RFID tags that use EEPROM are more expensive than factory programmed tags, where the number is written into the silicon when the chip is made, but they offer more flexibility because the end user can write an ID number to the tag at the time the tag is going to be used.


Factory programming:

Some read-only have to have their identification number written into the silicon microchip at the time the chip is made. The process of writing the number into the chip is called factory programming. This data can't be written over or changed.

Field programming:

Tags that use EEPROM, or non-volatile memory, can be programmed after it is shipped from the factory. That is, users can write data to the tag when it is placed on a product.

FLASH:

A special type of EEPROM that can be erased and reprogrammed in blocks instead of one byte at a time. It is usually written in capital letters, but it is not an acronym.


Input-output ports:

Ports on an RFID reader that can be connected to external devices. An input port might be connected to a photoelectric eye to turn on the reader when an object enters the reader field. An output device might be connected to a door that opens when a tag is read.

Item-level:

A term used to discribed the tagging of individual products, as opposed to case-level and pallet-level tagging.


Lossy:

Characterized by or causing dissipation of energy. For instance, a cable is said to be a lossy cable if the signal attenuates as it travels through the cable.

License plate:

This term generally applies to a simple RFID that has only a serial number that is associated with information in a database. The Auto-ID Center promoted the concept as a way to simplify the tag and reduce the cost.

Memory:

The amount of data that can be stored on the microchip in an RFID tag. It can range from 64 bits to 2 kilobytes or more on passive tags.

Memory block:

Memory on the microchip in an RFID tag is usually divided into sections, which can be read or written to individually. Some blocks might be locked, so data can't be overwritten, while others are not.

Microcontroller:

A complete microprocessor on a chip. A microcontroller includes a central processing unit, RAM or EPROM, clock and control circuits, and serial and parallel I/0 ports.


NanoBlock:

The term Alien Technology uses to describe its tiny microchips, which are about the width of three human hairs.

One-time programmable:

Memory that can be written to, or programmed, only once and is afterwards write protected. After the memory is written to, it is like read-only memory.

One-time programmable tag:

Also called a field-programmable tag. An RFID tag that can be written to once and read many times (see WORM).


Physical Markup Language:

An Auto-ID Center-designed method of describing products in a way computers can understand. PML is based on the widely accepted eXtensible Markup Language used to share data over the Internet in a format all computers can use. The idea is to create a computer language that companies can use to describe products so that computer can search for, say, all "soft drinks" in inventory.


Commissioning a tag:

This term is sometime used to refer to the process of writing a serial number to a tag (or programming a tag) and associating that number with the product it is put on in a database.

Programming a tag:

Writing data to an RFID tag. When a serial number is first written to a tag, this is sometimes called "commissioning a tag."


Quiet tag:

An RFID tag that can be read only occasionally with the interrogator output at full power, or which can only be read at very close range.


Real-time locating system:

A system of finding the position of assets, using active RFID tags. The tags broadcast a signal, which is received by three reader antennas. The time each signal is received is passed on to a software system that uses triangulation to calculate the location of the asset. RTLS is used to find containers in a distribution yard, and many automakers use it to track parts bins within a large factory.


Savants:

A term used to describe distributed middleware designed by the Auto-ID Center to filter data from EPC readers and pass it on to enterprise systems. It was envisioned that Savants would reside on servers across the EPC Network and pass data to one another and act as a kind of nervous system for the network. The term is being phase out by EPCglobal and many of the functions of Savants are being incorporated in commercial middleware products.


Scanner:

An electronic device that can send and receive radio waves. When combined with a digital signal processor that turns the waves into bits of information, the scanner is called a reader or interrogator.


Semi-passive tag:

Similar to active tags, but the battery is used to run the microchip's circuitry but not to broadcast a signal to the reader. Some semi-passive tags sleep until they are woken up by a signal from the reader, which conserves battery life. Semi-passive tags can cost a dollar or more. These tags are sometimes called battery-assisted tags.


Sensor:

A device that responds to a physical stimulus and produces an electronic signal. Sensors are increasingly being combined with RFID tags to detect the presence of a stimulus at an identifiable location.

Signal attenuation:

The weakening of RF energy from an RFID tag or reader. The energy emitted by the reader naturally decreases with distance. The rate of decrease is proportional to the inverse square of the distance. Passive UHF RFID tags reflect back a signal at very low power levels. A tag’s reflected signal decreases as the inverse fourth power of the distance between tag and reader. Attenuation can be increased by external factors as well. For instance, water absorbs UHF energy, causing signal attenuation.


Silent Commerce:

This term covers all business solutions enabled by tagging, tracking, sensing and other technologies, including RFID, which make everyday objects intelligent and interactive. When combined with continuous and pervasive Internet connectivity, they form a new infrastructure that enables companies to collect data and deliver services without human interaction.

Subscriber identity module:

An essential component of a GSM mobile phone. It contains the identity of the subscriber and assures the authentication during the access into the network and provides data storage for other subscriber related information, such as a personal address books.

Contactless smart card:

An awkward name for a credit card or loyalty card that contains an RFID chip to transmit information to a reader without having to be swiped through a reader. Such cards can speed checkout, providing consumers with more convenience.


Smart cards:

A credit card or other kind of card with an embedded microchip. When the card uses RFID technology to send and receive data it is called a contactless smart card.

Smart label:

A generic term that usually refers to a bar code label that contains an RFID transponder. It's considered "smart" because it can store information, such as a unique serial number, and communicate with a reader.

Intelligent reader:

A generic term that is sometimes used to describe a reader that has the ability to filter data, execute commands and generally perform functions similar to a personal computer.


Tag talks first:

A means by which a reader in a passive UHF system identifies tags in the field. When tags enter the reader's field, they immediately communicate their presence by reflecting back a signal. This is useful when you want to know everything that is passing a reader, such as when items are moving quickly on a conveyor. In other cases, the reader wants to simply find specific tags in a field, in which case it wants to broadcast a signal and have only certain tags respond. (See Reader talks first.)

Reader talks first:

A means by which a passive UHF reader communicates with tags in its read field. The reader sends energy to the tags but the tags sit idle until the reader requests them to respond. The reader is able to find tags with specific serial numbers by asking all tags with a serial number that starts with either 1 or 0 to respond. If more than one responds, the reader might ask for all tags with a serial number that starts with 01 to respond, and then 010. This is called "walking" a binary tree, or "tree walking." (See singulation.)


Time division multiple access:

A method of solving the problem of the signals of two readers colliding. Algorithms are used to make sure the readers attempt to read tags at different times.

Transceiver:

A device that both transmits and receives radio waves.

SMART CARD

ACCESS CONTROL / ACCESS CARD / ID CARDS / EMPLOYEE CARD SECURITY SYSTEM

Glossary of Access Control and Security Industry Terms


A

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.


B

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.

C

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.


D

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.


E

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.

F

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.


G

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.


H

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.


I

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.


J

Jumper - A plugable, movable device that allows connections to be made between points on a circuit board.


K

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.


L

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.


M

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 ReaderA 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.


N

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.


O

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.


P

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.


Q

- no descriptions -


R

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.


S

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.

T

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.


U

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.


V

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.


W

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.