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

ANSI - American National Standards Institute. An industry group that develops and maintains voluntary manufacturing standards.

Application Identifier - Consists of two or more digits that indicate the format of a data element in the UCC/EAN-128 symbology. It defines uniquely the meaning and format of the data element (see also Label IDs).

ASCII - American Standard Code for Information Interchange. The format uses a 7-bit plus parity code to represent 128 letters, numbers, punctuation marks and control characters. ASCII is a standard transmission code in the United States.

Aspect Ratio - The ratio of bar 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.

Autodiscrimination - The ability of bar code reading equipment to recognize and decode more than one symbology (see also Barcode Symbologies).

B

Bar - The darker element of a printed barcode symbol. Bars may be presented horizontally or vertically.

Barcode - A series of parallel adjacent dark bars and white spaces sized and arranged to represent data.

Barcode Density - The number of data characters per inch.

Barcode Label - A label which carries a barcode symbol and is suitable to be affixed to an article.

Barcode Symbology - The protocol that defines a standard for arranging bars and spaces, such as Code 39, UPC-A and Code 128 shipping container marking code (see also Symbologies Descriptions).

Bar Length - The bar dimension perpendicular to the bar width, also called bar height.

Bar Width - The thickness of a bar measured from its front edge (closest to the start character) to its rear edge.

Baud Rate - Communication speed measured in the number of bits per second.

Bidirectional - A barcode symbol capable of being read sucessfully, independent of scanning direction.

C

CDRH - Center for Devices and Radiological Health. CDRH is the federal agency that regulates laser product safety. It has defined classes of laser products based on their power output during operation.

CDRH Class I - This is the lowest CDRH power classification for laser products. Laser products in this class are considered intrinsically safe even if all laser output were directed into the pupil of the eye. Products in this class require no special operating procedures.

CDRH Class II - Laser products in this class pose no danger for unintetional direct human exposure. They require no additional software mechanisms to conform to this limit.

CCD - Charge Coupled Device. A type of barcode reader that operates by flashing and LED, creating a reflected image onto photosensitive material, and digitizing that image (see also Barcode Scanning).

Character - 1) A single group of bars and spaces which represent an individual number, letter, punctuation mark, or other symbol. 2) A graphic shape representing a letter, numeral, or other symbol. 3) A letter, digit, or other symbol that is used as part of the organization, control, or representation of data.

Check Digit - A digit used to verify that a symbol was decoded correctly. Check digits are optional for all symbologies except UPC (see also Barcode Symbologies).

Codabar - A discrete, self-checking symbology whose character set contains the numbers 0 to 9 plus six other characters (- $ : / , +) (see also Barcode Symbologies).

Code 128 - A high-density symbology that supports all 128 ASCII characters without requiring additional elements (see also Barcode Symbologies).

Code 39 - (Code 3 of 9). An alphanumeric symbology whose character set contains the numbers 0 through 9 plus six other characters (- $ : / , +) (see also Barcode Symbologies).

Continuous Code - A symbology in which all spaces are components of the characters. Continuous codes do not include any intercharacter gaps, enabling them to offer a higher density of information.

D

Data Identifier - A barcode character (or string of characters) that defines the general category or specific use of the data that follows.

Decode - To recognize a barcode and interpret its information.

Decode Algorithm - A method used to convert pulse widths into data representing the information contained in a barcode.

Decoder - The electronic package which receives the signals from the scanner, translates the signals into meaningful data and transmits the data to other devices.

Depth of Field - The distance between the maximum and minimum plane in which a code reader is capable of reading symbols.

Discrete Code - A symbology in which spaces between the characters are not part of the code.

Discrete 2 of 5 - A binary symbology in which each character is represented by a set of five bars, two of which are wide. The wide bars indicate which character is encoded. This symbology supports only the digits 0 through 9 plus Start/Stop characters.

E

EAN - European Article Number. A European / International version of UPC that is used primarily in retail applications. In this symbology, the elements are defined in metric units (see also Barcode Symbologies).

Element - A single bar or space in a barcode.

EMV - Europay, Mastercard, Visa. The competing organizations put aside their differences in 1993 and decided to work on completing the standards, referred to as EMV specifications.

F

First-Read Rate (FRR) - The percentage of times a symbol is successfully scanned on the first try.

H

Horizontal Symbol -  A barcode symbol displayed so that its bars resemble a picket fence.

Host Computer - A computer that supports other computers in a network.

I

IEC - International Electrotechnical Commission. IEC is the international agency that regulates laser product safety. It has defined classes of laser products based on their power output during operation.

IEC Class I - (IEC 825 Class I). This is the lowest IEC power classification for laser products. Laser products in this class require a software restriction of 120 seconds or less of laser operation within any 1000 second window and automatic shutdown of the laser if the oscillating mirror fails.

Intercharacter Gap - Spaces between adjacent characters within a symbology.

Interleaved Barcode - A symbology in which characters are paired, using bars to represent the first character and spaces to represent the second.

Interleaved 2 of 5 - A binary symbology in which pairs of characters are represented by a set of five bars interleaved with five spaces. The wide elements indicate which character is encoded. Interleaved codes offer a higher density of information. This symbology supports only the digits 0 through 9 plus Start/Stop characters (see also Barcode Symbologies).

L

Laser - An acronym for Light Amplification by Simulated Emission of Radiation. Components include an energy source, the material to convert the energy to light and the optics to direct the beam of light into a narrow cone.

Laser Diode - A laser made from a semi-conductor material and powered by applying electrical power to the material.

Laser Scanner - An optical barcode reading device using a low-energy laser light beam as its source of illumination.

LED - Light-Emitting Diode. A semi-conductor often used as a light source in scanners.

N

Non-Read - A scan attempt which does not yield any data.

Numeric - A character set that includes only numbers.

O

Optical Throw - The distance from the scanner face to the closest point at which a symbol can be read.

Orientation - The alignment of a barcode symbol with respect to the horizontal. Two possible orientations are horizontal with vertical bars and spaces (picket fence) and vertical with horizontal bars and spaces (ladder).

P

Parameter - A variable that can be assigned different values.

PDF417 - A 2-dimensional barcode symbology that encodes large volumes of data. It is a standard for functions other than fast auto-sortation or small component marking (see also Barcode Symbologies).

Pitch - Rotation of a barcode symbol about an axis parallel to the direction of the lines.

Q

Quiet Zone - A clear space that contains no dark marks and either precedes the start character or follows the stop character of a barcode.

R

RAM - Random Access Memory. Serves as the computer's work area, whose contents are changed by programs and user commands; when the computer is turned off, the contents are cleared.

Range - In RF systems, the maximum distance between antenna and/or RF tags that still permits communication.

Read Mode - The state in which the scanner is ready to decode a barcode.

Read Rate - The ratio of the number of successful reads on the first attempt to scan to the total number of attempts.

Resolution - The narrowest element dimension which can be sensed by a particular reading device or printed with a particular device or method.

RF Tag - Identification label capable of transmitting data via RF. Some tags also receive and store data.

RS-232 - A common interface standard that permits DTEs and DCEs to connect successfully.

S

Scanner - An electronic device designed to scan and decode barcodes. Scanners consist of: 1) Light source to illuminate the barcode. 2) Photodetector to capture and measure the reflected light. 3) Signal conditioner to convert the output from the photodetector to a digitized pattern (see also Barcode Scanning).

Self-Checking Code - A symbology which uses an algorithm to check for encoding errors.

Serial Communication - Data transmitted one bit at a time, sequentially, over a single wire. The most common serial interface is RS-232C.

Skew - Rotation of a barcode symbol about an axis parallel to the symbol's length.

Smart Cards - Credit card-sized packages containing one or more microchips, which may have IC memory and/or micro-processors. Sometimes refers to stored value cards that have a magnetic stripe but no chip (see also Product Families).

Space - The lighter element of a barcode, usually formed by the background between bars.

Space Width - The thickness of a space from its front edge (closest to the start character) to its rear edge.

Spread Spectrum - Radio frequency technology that requires no FCC site license. The frequency is constantly changed following a known algorithm to relieve conflict from multiple users at one frequency.

Start/Stop Character - A pattern of bars and spaces that indicates where and how to read the barcode. Start and stop characters are usually located to the left and right margins in horizontal codes.

Store-Value Card - A plastic card with value encoded on the magnetic stripe. With each use, the magnetic stripe is re-encoded with updated value information.

Symbol - A combination of characters in barcode forming a complete, scannable entity.

Symbology - The rules and conventions that define how data is represented for a particular type of barcode (see also Barcode Symbologies).

Synchronous Communication - Transmission of data which does not use special control bits, but requires a clock signal for coordinates between the devices.

T

Tilt - Rotation of a barcode symbol about an axis perpendicular to the substrate.

U

UCC - Uniform Code Council. The organization which administers the UPC code and other retail standards, such as the Uniform Container Symbol (UCS) and the Universal Product Carton Code (UPCC).

UPC - Universal Product Code. A numeric symbology in which each character consists of two bars and two spaces. UPC is the standard symbology used for retail food packages in the United States (see also Barcode Symbologies).

USB - Universal Serial Bus. A universal connector that replaces serial and parallel connections for PC peripherals with a standard plug and cable carrying both data and power.

USS - Uniform Symbol Specification. The current series of symbology specifications published by AIM.

V

Vertical Symbol - A barcode symbol displayed so that the bars and spaces resemble a ladder.

VLD - Visible Laser Diode. Laser light is produced in the visible spectrum; VLDs can read all color barcodes and have a great depth of field, but can be inhibited by high ambient light.

W

Wedge - A device that plugs in between a keyboard and a PC. Includes a scanner allowing data to be entered either by a keyboard or scanner.

X

"X" Dimension - The nominal dimension of the narrow bars and spaces in a barcode symbol (see also Barcode Quality).

Xon/Xoff - A communication protocol using two control characters (Xon, Xoff) to start and stop data transmission.