rfid ready - Auto-ID-/RFID-News & Articles

RFID glossary

Active Tag
An Active RFID-tag contains a battery and a transmitter to send information to an RFID reader, rather than reflecting a signal back to the reader from a tag (as a passive tag does).

Agile Reader
An RFID reader that can read tags operating at different frequencies or different communication protocols.

Air interface protocol
The standards that govern how RFID tags and readers communicate. 

Antenna
A conductive structure specifically designed to couple or radiate electromagnetic energy. In a driven mode, the structure is a transmitter antenna. In receiver mode, the structure is a receiver antenna. In RFID systems, the antenna may be used to both transmit and receive electromagnetic energy. 

Anti-collision
Anti-collision algorithms are used to collect data from multiple RFID tags at the same time from the same RFID reader without interference.

Auto-ID Center
The original non-profit organization that helped develop RFID system technology. This work is now continued by EPCglobal.

Backscatter / Backscattering
The communication method between a passive RFID tag and a reader. An RF signal sent by a reader is reflected back to the reader from the tag, which is modulated to transmit data.

Baud
A unit of transmission speed representing the number of signalling events per unit time. Often confused with bits per second (bps).

Beacon
An active or semi-passive RFID tag that is programmed to wake up and broadcast a signal at pre-set intervals.

Bit
Abbreviation for binary digit. One bit represents a 1 or 0 in a binary numeral, or a true or false logical condition. A bit is physically represented as a high (1) or low (0) voltage in a circuit.

Commissioning
Writing data to an RFID tag for the first time. Thic can happen at the factory or later using a smart label printer.

Concentrator
A device used to gather data from multiple RFID readers at the same time.

Contactless smart card
A credit card or buyer card that contains an RFID chip to transmit information without having to be swiped through a reader.

Data Rate (Data Transfer Rate)
In a radio frequency identification system, the rate at which data is communicated between the tag and the reader. Usually measured in bits per second (bps).

EAN International
The international group that administers bar code standards in many parts of the world.

Electromagnetic Field
An electromagnetic field is produced when electrically charged particles are set in motion. The frequency of an electromagnetic field is measured in Hertz and is related to its wavelength.

Embedding
This operation consists in placing the tag in the body of a product.

EPCglobal
The organization set up to commercialize RFID technology, which has taken over this task from the Auto-ID Center.

Far-field communication
An RFID tag that is located one full wavelength away from an RFID reader.

Frequency
The number of complete cycles a signal executes in a unit of time. Usually measured in Hertz (cycles per second).

HF
see "high frequency"

High Frequency Tags
RFID tags that communicate with readers operating at 13.56MHz range.

ic
see "Integrated circuit"

Inductive coupling
A RFID reader antenna and a tag antenna each have a coil, which together form a magnetic field. The RFID tag draws electrical energy from this field, which powers its microchip. The microchip then changes the electrical characteristics of the tag antenna. These changes are sensed up by the reader antenna and converted into a serial number for the RFID tag.

Inlay
A "blank" RFID tag that is usually part of a smart label. Smart label printers are used to write data to the RFID at the same time printing bar code data on the label. Also called an inlet.

Inlet
see "Inlay"

Integrated Circuit
An electronic circuit in which many active or passive elements are fabricated and connected together on a continuous substrate. Also known as a chip

Interference
Electronic noise or other unwanted signals that reduce the performance of a system.

International Standards Organization
An international association that provides global standards for communications and information exchange between semiconductor companies, software developers and smart card makers

Interrogator
Another name for an RFID reader.

ISO
see "International Standards Organization"

License plate
A simple RFID system that only tracks RFID tag serial numbers and no other information.

Memory
General term for computer hardware that stores data in electrical or magnetic form. A variety of random access (RAM), read-only (ROM), write once, read many (WORM) and read/write (RW) memory devices can be distinguished.

Microprocessor
An integrated circuit that serves as the Central Processing Unit controlling an electronic device. It provides programmable intelligence that controls peripheral devices, memory and power functions.

Middleware
In the context of an RFID system, refers to software that is used to filter RFID data and pass on useful information to enterprise software applications for further processing.

Multi-Read
A feature commonly used in RFID systems to read the data of several tags at the same time while in the same RF field simultaneously. See anti-collision

Near-field communication
An RFID tag that is within a full wavelength of an RFID reader.

NFC
see near field communication

Passive tag
An RFID tag without a power source or transmitter. Radio waves from an RFID reader are collected from the RFID tag antenna, which powers up the microchip in the tag. The tag is then able to send back information stored in the chip to the reader.

Phantom read
When a RFID reader reports the presence of a tag that doesn't exist.

Phase Shift
Difference of phase between the 13.56 MHz field emitted by two antennas. This feature is dedicated to rotating field applications and three-dimensional tag detection.

Protocol
A set of standards governing a particular function enabling tags, readers and host systems to exchange data.

Proximity
Term often used to indicate closeness of one system component with respect to another, such as the tag with respect to a reader.

Radio Frequency Identification System
An automatic identification and data capture system consisting of one or more readers and several tags in which data is exchanged by means of inductively-coupled or radiating electromagnetic carriers.

Read
The process of transferring the data stored in a tag memory to the reader.

Read Rate
The maximum rate at which data can be communicated (read) between a tag and the reader. Usually measured in reads per second.

Read-Only
Term applied to a tag in which the data is written (programmed) once during manufacturing and afterwards can only be read and never changed.

Reader
An electronic device used for communication between RFID tags and a host computer system. A reader generally consists of an RF transmitter and receiver and an antenna for communicating with tags. A digital interface enables the reader to communicate with the host computer system.

Reader Talks First
Tag protocol for exchanges between the reader and the chip, where the tag waits for a command from the reader to which it responds.

Reading distance
The distance between the antenna of a reader and a tag over which the read function can be effectively performed. This distance is influenced by the orientation and angle of the tag with respect to the antenna, and possibly by environmental conditions.

RFID
RFID stands for Radio Frequency IDentification

RFID 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.

RFID tag
A microchip attached to an antenna in a package. An RFID tag contains a unique serial number at a mimimum, but commonly contain other information about a product. RFID tags can be passive, semi-passive or active.

Semi-passive tags
Similar to active RFID tags, but the battery is used only to run the RFID chip - not to broadcast a signal to a reader.

Slap and ship
Placing an RFID tag on a case or pallet just before it is shipped from a supplier. Used to meet a retailer's requirements.

Smart label
A bar-code label that contains an RFID tag.

Standards
A standard is a set of specifications defining the physical, electrical or logical properties of a device. See also International Standards Organization (ISO).

Tag
An electronic label consisting of a microprocessor and antenna coil that communicates with a reader by means of a radio frequency signal. It comes in various shapes and sizes. Also known as a transponder.

Tag Talks First
Tag protocol for exchanges between the reader and the tag, where the tag sends information continuously, without waiting for a specific command from the reader.

Transponder
A radio-frequency transmitter-receiver combination. Another term for a RFID tag.

Ultra High Frequency Tags
RFID tags that communicate with readers operating in the 869 MHz- 930MHz range

WORM
see "Write-once, read-many"

Write-once, read-many
A RFID tag that can be written to (changed) only once by a reader. Afterward, the tag can only be read.

ZigBee
Zigbee is the name of a specification for a suite of high level communication protocols using small, low-power digital radios based on the IEEE 802.15.4 standard for wireless personal area networks (WPANs). ZigBee is targeted at RF applications that require a low data rate, long battery life, and secure networking.