Auto-ID Glossary

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

- A -

Accuracy

A bar code verification term. The determination of whether any element width, or intercharacter gap width, differs from its nominal width by more than the printing tolerance.

Active tag

An RFID tag with a transmitter that sends data to a reader, rather than reflecting back a signal. Most active tags have their own power source, normally a battery.

Air interface protocol

The rules that control how RFID readers and tags communicate.

Antenna

A conductive element in an RFID reader or tag that enables the sending and receiving of data.

Anti-collision

Term for methods to prevent radio waves from multiple devices interfering with each other. Anti-collision methods provide for a reader to read multiple RFID tags nearly simultaneously.

ASCII

The character set described in the American National Standard Code for Information Interchange. ASCII is used for information interchange between data processing systems, communications systems, and associated equipment.

Aspect ratio

A bar code verification term. In a bar code symbol, the ratio of bar code symbol height to symbol length.

Asynchronous communication

Also referred to as start/stop transmission. Every character transmitted has special bits attached, telling the receiving device when the data begins and ends. Data is transmitted independently with no associated clock. See also Synchronous communication.

Autodiscrimination

The ability of bar code scanning and decoding equipment to recognize more than one symbology.

Auto-ID (Automatic identification)

Various methods that allow machines to identify objects independent of human intervention. Auto-ID technologies include bar codes, voice recognition, retina scans and RFID.

Auto-ID Labs

Research group for RFID, barcoding and other automatic identification technologies. The Auto-ID Labs network grew out of the original MIT Aut0-ID Center project. It includes seven research universities on four continents. The Center pioneered a network for using RFID to globally track products.

Average Background Reflectance

A bar code verification term. Expressed as a percent. See Reflectance.

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- B -

Background

The white spaces and quiet zones surrounding a printed bar code.

Backscatter

A method of communication used by passive RFID tags and readers, where the tag reflects back radio waves generated by a reader.

Bar Code

A technology that uses white spaces and black bars to represent encoded information. This encoded information can then be read with an optical device that converts the bars and spaces into an electrical signal, which is then decoded into the original characters.

Bar Code Character

A single group of bars and spaces that represents a specific individual number, letter, punctuation mark, or other symbol. This is the smallest subset of a bar code symbol that contains data.

Bar Code Reader

A device (light pen, laser gun, fixed scanner, etc.) used to read a bar code field.

Bar

The darker element of a printed bar code field.

Bar Width

The thickness of an individual bar measured from edge to edge of the same bar.

Battery-assisted passive tag

"Semi-passive" RFID tags with an onboard power source to run the circuitry, but which communicate with a reader using the same backscatter technique as passive tags.

Bi-directional

A bar code symbol capable of being read successfully if scanned in either direction.

BISYNC

Binary Synchronous Communication. Protocol supported by the IBM System i for communicating with other System i (iSeries, AS/400), IBM mainframe, System/36, and System/38 systems.

Black Mark

Sensor mark usually printed on the reverse (non-printing) side of tag stock, or on the liner (backing paper) of label stock.

Bluetooth

Industrial specification for wireless personal area networks. Connects devices such as mobile phones, laptops, PCs, printers, digital cameras, and video game consoles over a secure, globally unlicensed short-range radio frequency. Developed and licensed by the Bluetooth Special Interest Group.

BMP

Microsoft Windows bitmap graphics file format.

Butt Cut

Form of bar code label stock used in continuous operations. Butt cut stock usually yields an additional 10% more individual labels than die cut stock.
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- C -

CCD

Charge Coupled Device. Type of bar code scanner that uses LEDs (not lasers) to flood the bar code with light.

Character Set

Characters available for encodation in a particular bar code type. Not all bar code types can encode the entire ASCII character set.

Computer Integrated Manufacturing

Factory automation term where information is shared between computer aided design programs, materials resource planning (MRP) programs, and machine tools on the shop floor. Bar code data collection is an important part of a successful CIM implementation.

Class 0

Read-only tags (programmed only once) with 64-bit or 96-bit memory capacities. Class 0 tags operate in the UHF between 868 and 930 MHz. Class 0+ tags are rewritable.

Class 1

One-time programmable (OTP) tags that can be updated one additional time after being encoded. Class 1 tags have a 96-bit memory capacity and operate between 868 and 930 MHz.

Clear Area

See Quiet Zone .

Closed-loop systems

Vertical market applications for RFID that never leave the company's control. Used for internal RFID applications such as security ID or tracking assets. Open standards are less of an issue under closed-loop systems. Closed loop RFID is effectively used for internal tracking and management of assets and can often bring a quick ROI.

CODABAR

A numeric-only bar code type, in which each character is composed of seven elements four bars and three spaces. CODABAR is currently used in a variety of applications such as libraries, medicine, and overnight package delivery. Also known as USD-4 code, NW-7, and 2 of 7 code, it was originally developed for retail price-labeling use.

Code 39

A full alphanumeric bar code type composed of five bars, four spaces, and an intercharacter gap for each character. Code 39 is the standard for many industries, including adoption by the U.S. Department of Defense for its LOGMARS specification. Also known as USD-3 code and 3 of 9 code, it is one of three symbologies identified in the ANSI standard MH10.8M-1983.

Code 49

An extremely compact, multi-row, continuous variable bar code type capable of encoding the full 128 ASCII character set. It is ideally suited to applications where large amounts of data are required in a small space. The code consists of 2 to 8 rows. A row consists of a leading quiet zone, 4 symbol characters encoding 8 code characters, a stop pattern, and a trailing quiet zone. Rows are separated by a one module high separator bar. Each symbol character encodes two characters.

Code 128

A high density, variable length, full alphanumeric bar code type capable of encoding all 128 ASCII characters. It was designed for complex encoded product identification and is the basis of the UCC-128 marking specification. Code 128 has three subsets of characters. There are 106 printing characters in each set. Therefore, each character can have three different meanings, depending on the character subset used. Each Code 128 character consists of six elements -- three bars and three spaces.

Collision

Interference between more than one tag or reader.

CPI

Characters Per Inch. A common measurement for bar code density.

Cutter

Also called a knife. An integrated mechanism used to cut individual tickets from a roll of tag supply.
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- D -

Data identifier

A compliance marking term. Message prefixes in a bar code that define the general category or intended use of the data that follows.

Data Matrix

Two-dimensional matrix bar code consisting of black and white squares arranged in a square or rectangular pattern. The information to be encoded can be text or raw data. Error correction added to increase symbol strength allow the codes to be read even if they are partially damaged.

DC

Distribution Center . When goods are shipped to a distribution center, the container marking specifications are usually different from those required when shipping directly to a store.

DCE

Data Communications Equipment. Hardware interface standard for modems, protocol converters, and other communications equipment. To interface DCE devices with DTE (Data Terminal Equipment) devices such as terminals or PCs, a straight through serial cable is required. See also DTE .

Decoder

As part of a bar code reading system, the electronics that process the signals from the scanner, interpret the signals into meaningful data, and control the interface to other devices.

Depth of Field

The distance between the maximum and minimum surface in which a scanner is capable of reading bar codes of a specified X dimension.

DI

A compliance marking term. See Data Identifier .

Die Cut

Type of label supply used in on demand applications. See also butt cut .

Diffuse Reflection

A bar code verification term. The component of reflected light that emanates in all directions from the reflecting surface (as opposed to the focused light of the scanner laser reflected back to the scanner).

DPM (Direct Part Marking)

A technology used to produce two different surface conditions on an item, effectively creating a bar code by laser etching, molding, etc. DPM is required by the DoD for certain parts and assemblies.

DoD

The United States Department of Defense. The DoD mandates RFID tags on certain supplies for tracking and security.

Dot Matrix

A system of impact printing where individual dots are printed by tiny wires striking the supply through an inked ribbon.

DPI

Dots Per Inch. Used in comparing relative printing resolution of thermal printheads and laser print engines.

DSD

Direct Store Delivery. When goods are shipped directly to a store, the container marking specifications are usually different from those required when shipping to a distribution center.

DTE

Data Terminal Equipment. Hardware interface standard for display stations, personal computers, printers and other non-communications equipment. To interface a DTE printer with a DTE device such as a PC or a display station, a null-modem serial cable is required. See also DCE.

Dual Di-Pole

A bidirectional tag with two antennas, making it less sensitive to orientation, thereby increasing read capability.

Dumb reader

An RFID reader with that passes data on to other systems or smart readers but cannot itself filter data, execute commands and perform other functions. Compare with an intelligent reader.

Duty cycle

The maximum time for which an RFID reader can emit energy. For example, a ten per cent duty cycle means a reader is restricted to transmitting six minutes per hour.
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- E -

EAN

European Article Numbering system. The international standard bar code for retail food packages. The EAN-13 bar code type has 12 data characters, one more data character than the UPC-A code. An EAN-13 symbol contains the same number of bars as the UPC-A but encodes a 13th digit into a parity pattern of the left-hand six digits. This 13th digit, in combination with the 12th digit, represents a country code. The JAN-13 (Japanese Article Numbering system) is a special application of EAN-13.

EAS

Electronic Article Surveillance. Tags that can be switched on and off. Used to prevent theft from retail stores, libraries, etc.

EBCDIC

Extended Binary Coded Decimal Interchange Code. Developed by IBM, it is the character set used by the IBM System i (iSeries, AS/400).

EDI

Electronic data interchange. Intercompany, computer-to-computer business transactions.

EDIFACT

The international standard that supports EDI transactions across national boundaries.

EIRP

Effective Isotropic Radiated Power. A measure of the output of an RFID reader antenna. EIRP is typically measured in watts. Commonly used in the United States . See also ERP.

Element

A single bar or space in a bar code.

EM (Electromagnetic) interference

Interference caused by radiation emitted by electrical during normal operation. Can be caused by cell phones, laptop computers or other transmitters that emit signals which can interfere with other circuits.

Encode and Apply

Programming RFID labels with variable data on-demand. Unlike "Slap and Ship," Encode and Apply labels verify tags before application and automatically reject labels with bad tags, replacing them with good tags.

Encoder

A device that transmits and writes data to an RFID tag. Typically an RFID reader module developed for a specific application, such as printing.

Environmental Factors

External conditions that can affect or interfere with UHF products. E.g. the relative proximity of metal, liquids, significant reader activity, other RF “noise,” etc. These factors require process controls in terms of tag and reader placement. Readers also need proper adjustment for a given environment.

EPC

Electronic Product Code. A serial number containing information that identifies the manufacturer, product category and item.

EPCGlobal

The international organization responsible for RFID technological and ethical standards. EPCGlobal also promotes the adoption of RFID Auto-ID solutions

EPC Network

S ystem developed by Auto-ID center and administered by EPCGlobal for collecting and sharing data related to electronic product codes. It can be used to look up product information, such as pharmaceutical expiration date or manufacture date. It can also be used to track goods and establish a chain of custody/electronic pedigree.

ERP

Effective Radiated Power. Measures the output of a dipole antenna. ERP is generally measure in watts. Often used in Europe; different from EIRP more common in the US .

ETSI

European Telecommunications Standards Institute. Independent organization that aims to set telecommunications standards for Europe . The latest RFID-related standard is ETSI 302-208.

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- F -

FACT

Federation of Automated Coding Technologies. Because of the large number of groups that have been independently developing bar code standards, FACT was formed to foster interindustry communications and coordination. An "association of associations," FACT maintains a database of specifications and data identifiers.

Firmware

Computer programming instructions stored permanently in read-only memory. Most Bar Code and RFID readers can be updated to accommodate new protocols by changing the firmware.

First Read Rate

A bar code verification term. The ratio of the number of successful reads to the number of attempts. Commonly expressed as a percentage. Abbreviated as FRR.

Fixed beam scanner

A visible light or laser scanner that requires a more exact positioning of a bar code than a moving beam scanner.

Form factor

Essentially the material, format and shape of the RFID tag. Form factors include adhesive labels, plastic cards and key fobs.

FRR

First Read Rate.
See First Read Rate

Function code

Function (FNC) codes define instructions for a bar code reader decoding Code 128 bar codes. FNC 1, for example, is a required component of the UCC-128 specification. FNC 2 tells the reader to store the data read and transmit it with the next symbol. FNC 3 is reserved for code reader initializing and other reader functions. FNC 4 is reserved for future use.
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- G -

Gen2

Shorthand for EPC Class 1 Generation 2. The standard ratified by EPCglobal for the air interface protocol for the latest (second generation) EPC technologies. (See EPC.)

Global Trade Item Number (GTIN)

Developed by Global Standard One (GS1), an organization for developing international commerce standards. The code is used to store and retrieve product information in a global database.

GPS

Global Positioning System. Satellite navigation system used for determining the user's precise location and providing an accurate time reference worldwide.

Guard Bars

The bars that are at both ends and center of a UPC and EAN bar code type. They provide reference points for reading, serving a function similar to start/stop codes.
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- H -

HeNe Laser

A helium neon laser commonly used in bar code scanners.

HF

High Frequency radio waves, from 3 MHz to 30 MHz. RFID tags designed for the HF range typically operate at 13.56MHz.

Horizontal bar code

A bar code type presented in such a manner that its overall length dimension is parallel to the horizon. The bars are presented in an array which looks like a picket fence.

Hybrid (semi-active) RFID Tag

Tag that has a small internal power supply, is triggered by a reader. After interrogation, the tag goes back to being passive.
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- I -

ILD

Infrared laser diode. Used in some hand laser scanners to project a light beam.

Infrared

The band of light wavelengths too long to be seen by the human eye. Used in access control and security applications where bar code fields must not be visible by human eye -- only to an infrared scanner.

Interleaved 2 of 5

A high density, self-checking, continuous numeric bar code type in which each character is composed of five elements: five bars or five spaces. Of the five elements, two are wide and three are narrow. The bar code is formed by interleaving characters formed with all spaces into characters formed with all bars. Total number of digits must be even.

Interrogator

Another name for a reader because it "interrogates" the tag for data.

Intelligent reader

RFID reader with some processing, filtering and command execution ability, similar to that of a PC.

ISO/IEC

International Organization for Standardization. International organization of 146 countries setting individual national standards institutes.

Item-level

Tagging of individual items, as opposed to tagging cases or pallets.
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- J -

(empty)
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- K -

Kill Command

A code within the RFID tag that gets activated once and then permanently disables the tag. Limits tracking of purchased items for privacy protection.
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- L -

Label gap

The space between adjacent labels on continuous form, die cut supply.

Ladder

A bar code field printed in a rotation perpendicular to the horizon so that the individual bars appear as rungs on a ladder. Also referred to as a vertical bar code.

Laser

Light Amplification by the Stimulated Emission of Radiation. A focused light source (as opposed to LEDs used in wands and CCD readers) used in fixed, moving beam, and handheld scanners.

LED

Light-emitting diode. The light source often used in light pens.

LF

Low frequency. RFID tags designed for the LF range generally operate at 125 kHz or 134 kHz.

Light pen

Also known as a wand. A scanning device which is used as a hand held bar code reader. Requires direct contact with the printed bar code field.

LOGMARS

A compliance marking term. Logistics of Marking and Reading symbols. A Department of Defense marking specification.

Low Frequency (LF) RFID

RFID over the 125Kz band. Usually used by small, inexpensive products with short read ranges (12 inches or less). Typical uses are security access cards quick payment applications.
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- M -

Magnetic Stripe

Strip of magnetic recording material on a card that contains data which can be read to identify the holder and or the associated account.

Mandate

Requirements imposed by major client organizations such as Wal-Mart, the United States Department of Defense for vendors to place RFID tags on all shipments in order to improve supply chain management. The size and power of these organizations mandating RFID had an impact on suppliers worldwide. The original Wal-Mart Mandate required its top 600 suppliers to ship all products with Gen 2 RFID tags identifying each pallet and was supposed to extend to 1,400 stores by the end of 2007. However, the logistics of implementation for vendors have forced RFID deadlines to be extended. As the technologies become more user friendly and less expensive, most companies will likely use RFID tags on their shipments. (See Wal-Mart Mandate)

MaxiCode

A machine readable symbol system UPS. Used for tracking and managing the shipment of packages. A MaxiCode resembles a barcode, but uses dots arranged in a hexagonal grid instead of bars. Because of its unique design, MaxiCode is often called "Bird's Eye" or "Target." The bull's eye at the center allows MaxiCode symbols to be scanned and read regardless of orientation, even on a package traveling rapidly.

Memory

Amount of data that can be stored on an RFID tag's chip. For passive tags, this typically ranges from 64 bits to a few kilobytes. Active tags can generally accommodate more memory than passive tags.

Microwave

High frequency wave. Microwave RFID tags typically operate at a frequency of 2.45GHz.

Middleware

Software that sits between the reader and enterprise applications. Generally resides on a server. Middleware performs operations like filtering and smoothing of the raw RFID data. It can also manage networked readers.

mil

One one-thousandth of an inch (0.001"). Unit of measurement used in bar code specifications.

Misread

A condition which occurs when the data output of a reader/decoder does not agree with the data encoded in the bar code field.

Module

The width of the narrow bars in a bar code.

Modulation

A range of techniques for encoding and transmitting information on a carrier signal. Types of modulation include frequency modulation, amplitude modulation and phase modulation.

Moving beam scanner

A device where scanning is achieved by mechanically moving a light beam through the bars of a bar code field.
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- N -

Nanometer

A bar code verification term. Unit of measure used to define the wavelength of light.

Net Data Density

A bar code verification term. The net data density of a linear bar code symbol is determined by dividing the number of characters in the symbol by the overall symbol length, measured from the leading edge of the start code to the trailing edge.

Nominal

A bar code verification term. The exact (or ideal) intended value for a specified parameter. Tolerances are specified as positive and negative deviations from this value.
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- O -

OCR

Optical Character Recognition. Technology for machine reading of human readable text.

On demand

A printing mode where one label at a time is printed. The label is presented to the operator, separated from the backing paper. When the label is taken from the printer, the next label is printed and presented. Also known as Demand mode.

Opacity

A bar code verification term. 1).The optical property of a substrate material that measures the show through from the back side or the next sheet. 2).The ratio of the reflectance with a black backing to the reflectance with a white backing. 3).Ink opacity is the property of an ink that prevents the substrate from showing through.

Optical throw

The minimum distance a bar code can be away from a scanner and still be read.

Optional User Memory

Added memory available on a tag that can be used by any member along the supply chain. Can be used for routing information or other applications to increase tracking efficiency.

Orientation

Two possible bar code field orientations are horizontal with vertical bars and spaces (picket fence) and vertical with horizontal bars and spaces (ladder).

Overhead

The bars and spaces representing the start, stop, function codes and check characters required by some symbologies. These increase the length of the bar code but do not affect the message content.
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- P -

Passive tags

An RFID that does not have its own transmitter and power source. The energy required to run the tag's circuitry is obtained from the radio waves emanated by the reader.

PCS

A bar code verification term. Print contrast signal. A measurement of the ratio of the reflectivity between the bars and spaces of a bar code field, commonly expressed in percent.

PCX

ZSoft Paintbrush bitmap graphics file format.

PDF 417

Portable Data File 417 is a two-dimensional bar code developed by Symbol Technologies, Inc. It is the most widely used 2D bar code (more than one row of codes) and it can hold up to 1,800 bytes of any digital data in an area the size of a business card.

Picket fence

A bar code type whose length is printed horizontally so that the bars are presented in an array which looks like a picket fence.

PLU

Price Look-Up. In a retail POS (Point Of Sale) system, the UPC bar code field is a key field in a price file that when scanned, retrieves a price for the encoded item.

Portal

A door or other point in a facility surrounded by fixed RFID readers to identify and track the flow of product. Dock doors are a typical example.

Postnet Code

A bar code symbology used primarily by the U.S. Postal Service for mail sortation. All bars and spaces are the same width. ZIP Code information is encoded into the particular arrangement of tall and short bars.

Print Quality

A bar code verification term. The measure of compliance of a bar code symbol to the requirements of dimensional tolerance, edge roughness, spots, voids, reflectance, PCS, quiet zone, and encodation.

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- Q -

QR

Quick Response. A retail industry initiative to improve inventory turnaround through the use of EDI, bar code scanning, and the sharing of merchandise movement data with vendors.

Quiet zone

A clear space, containing no machine readable marks, which precedes the start character of a bar code field and follows the stop characters. Sometimes called the "clear area."

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- R -

Read range

Distance from which a reader can communicate with a tag. Factors that affect the read range of a passive tag include frequency, reader power and antenna design.

Read rate (bar codes)

A bar code verification term. The ratio of the number of successful reads to the total number of attempts.

Read rate (RFID)

Indicates the number of tags that can be read within a given length of time. Read rate is also used as the maximum rate at which data can be read from a tag.

Read-only

Data stored in read-only RFID tags cannot be changed by a reader.

Read-write

Tags that can store and use new information. Can be changed many times by a reader.

Reader

Hardware that communicates with RFID tags. A reader has one or more antennas attached to it which emit radio waves and receive signals back from the tags. Many readers have the ability to write data as well as read data. See Interrogator.

Reflectance

A bar code verification term. The ratio of the amount of light which is reflected back from the white spaces of a bar code during scanning to the amount of light reflected under similar illumination conditions.

Resolution

The narrowest element dimension which can be recognized by a particular scanning device or printed with a particular device or method.

RF (Radio Frequency) network

A technology that connects devices using electromagnetic waves instead of physical cabling.

RFID

Radio Frequency Identification. A method of uniquely identifying items by transmitting and receiving electromagnetic (radio) waves.

RFID Pilot

Test for new RFID solutions. Pilots might be run by companies to help meet mandate requirements or to test new applications of RFID technologies.

Ribbon

A plastic tape with several layers of material, one of which is thermal wax, that when melted, produces the visible marks on the labels installed on a thermal transfer printer.

Rollout

Pilots that indicate a good return on investment (ROI) are then put into expanded deployment. This benefits the testing company and the RFID industry as a whole.

RS-232

A common communication interface standard that permits DTEs and DCEs to connect successfully.
RTLS (Real Time Location System)
Also called Real Time Locating Systems, RTLS tracks and identifies the location of objects in real time using badges or tags attached to or embedded in objects. Readers receive the signals from these tags to determine their locations.

RuBee

wo way wireless protocol that uses Long Wave (LW) magnetic signals to send and receive data packets in a local regional network. Similar to WiFi and Bluetooth, but RuBee uses a lower frequency, slower carrier. RuBee, however offers low power consumption and operates near steel and water, making it practical for sensors, controls, or actuators and indicators.

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- S -

Savants

Distributed middleware designed by the Auto-ID Center to filter data from EPC readers and pass it on to enterprise systems.

Scanner

An electro/optical device that converts the bars and spaces of a bar code field into electrical signals.

SDLC

Synchronous data link control. Protocol supported by the IBM System i for communicating with other IBM System i (iSeries, AS/400), mainframe, System/36, and System/38 systems.

Semi-active tag

Another name for a battery-assisted tag.

Semi-passive tag

Another name for a battery-assisted tag. Uses battery to run circuitry but does not broadcast its own signal.

SER

A bar code verification term. Substitution error rate. The rate of occurrence of incorrect characters.

Show Through

A bar code verification term. Generally undesirable property of a supply that permits underlying markings to be seen.

SKU

Stock Keeping Units. In a distribution/retail environment, a generic term for item number.

Slap and ship

The process of applying an RFID label to a case or pallet just before it leaves a supplier's facility. Often used by companies for basic compliance with companies to require shipments with RFID tags.

SNA

System Network Architecture. Enterprise communications standard developed by IBM.

Space width

A bar code verification term. The thickness of a space measured from the edge closest to the symbol start character to the trailing edge of the same space.

Spectral Response

A bar code verification term. The variation in sensitivity of a test surface to light of different wavelengths.

Stacked code 

Maxicode, 16K and Code 49 are examples where a long bar code field is broken into sections and "stacked" one upon the other, resulting in codes that are extremely compact.

Stacker

An optional electromechanical accessory that is invaluable for unattended, organized, printing and cutting of multiple batches of tags.

Standard

A compliance marking term. A set of rules, specifications, instructions and directions to use a bar code or other automatic identification system. Usually issued by a trade organization.

Start-stop character

A special bar code character that provides the scanner with start and stop reading instructions as well as scanning direction indicator.

Strap

Component of a tag connecting the chip to the antenna.

Substrate

The surface on which a bar code field is printed. Can be a label, tag, or paper supply.

Supply

See substrate.

Symbol

A combination of bar code characters, including start/stop characters, quiet zones, data characters, and check characters required by a particular symbology, which form a complete, scannable entity.

Symbol Length

The distance between the outside edges of the quiet zones on the two ends of a bar code field.

Symbology

Bar code type.

Synchronous communication

Transmission of data which does not use special control bits, but requires a master clock signal for coordination between the devices. The clock may be a separate signal, or it may be part of the data.

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- T -

Tag

Microchip attached to an antenna, enclosed in label or other "package" so it can be applied to an object.

T&A

Timeand Attendance. An application using bar code employee badges and bar code slot reading terminals to enter employee start/stop data.

Thermal direct

A printing method where dots are selectively heated and cooled and dragged upon heat-sensitive paper. The paper turns dark in the heated areas.

Thermal transfer

A printing method like thermal direct except a onetime ribbon is used and common paper is used as a supply. This eliminates the problems of fading or changing color inherent in thermal direct printing.

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- U -

UHF

Ultra High Frequency: transmitting between 300 MHz and 3 GHz. Typically UHF RFID tags operate in a region between 860 MHz to 960MHz. At present, there is no universally approved global frequency for UHF RFID use.

UID

Unique Item Identifier, a value in the Item Unique Identification system used by the US Department of Defense for the identification of accountable equipment as per DoD Instruction 5000.64.

UPC

Universal Product Code. The standard bar code type for retail products in the United States . See also UPC-A and UPC-E.

UPC-A

A fixed length, numeric, continuous bar code type used primarily in the retail industry for labeling packages. The UPC-A symbol encodes a number system character, 10 digits of data, and a Mod 10 check digit for error correction.

UPC-E

A UPC symbol encoding six digits of data in an arrangement that occupies less area than a UPC-A symbol. The UPC-E bar code type is a shortened version of the UPC-A bar code type in which zeroes are suppressed, resulting in codes that require less printing space. Used for labeling small items.

UPCC

A compliance marking term. Uniform Product Carton Code, a standard administered by the UCC.

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- V -

Verifier

A device that makes measurements of the bars, spaces, quiet zones and optical characteristics of a bar code field to determine if the code meets the requirements of a specification or standard.

Vertical bar code

A bar code field printed in a rotation perpendicular to the horizon so that the individual bars appear as rungs on a ladder.

Visible laser diode

Used in some hand laser scanners to project a beam of light visible to the human eye, simplifying the scanning process.

Void

A bar code verification term. An undesirable absence of ink in a bar.

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- W -

Wal-Mart Mandate

Wal-Mart made RFID front page news in 2003 when it issued a mandate requiring its top 100 suppliers to attach RFID tags positively identifying all cases and pallets by Jan. 1, 2005 . Wal-Mart has since relaxed its requirements allowing suppliers more time. But industry experts think eventually such tagging will become mandatory with suppliers to all major retailers.

Wand

See Light pen.

Wedge

A device that plugs in between a keyboard and a terminal or PC. Allows data to be entered either by the keyboard or an attached scanner.

WINS

A compliance marking term. Warehouse Information Network Standard. Defines EDI transaction types for the warehouse industries.

WIP

Work-In-Progress/Process. An application using bar code totes and bar code scanners to track lots through a manufacturing operation.

WORM

Write Once Read Many. A tag that a user can write to just once.

Write range

Distance from which data on an RFID tag can be written or changed.

Writer

An OS/400 program that serves as a link between an output queue and a printer. Normally the writer is started automatically at OS/400 IPL time.

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- X -

X-dimension

The width of the narrow bars and spaces in a bar code type; usually measured in mils.

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- Y -

(empty)
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- Z -

ZigBee

A wireless network used for home, building and industrial control. Designed for low power drain, it is slower than Wi-Fi or Bluetooth.