Glossary of Barcode Terms

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- 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.

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.

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

- B -

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

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.

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

BISYNC
Binary Synchronous Communication. Protocol supported by the AS/400 for
communicating with other 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.

BMP
Microsoft Windows bitmap graphics file format.

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

- 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.

Clear Area
See Quiet Zone.

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.

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.

- 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.

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).

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.

- 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.

EBCDIC
Extended Binary Coded Decimal Interchange Code. Developed by IBM, it is the
character set used by the IBM AS/400.

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

EDIFACT
The international standard that supports EDI transactions across national
boundaries.

Element
A single bar or space in a bar code.

- 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.

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.

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 intializing and
other reader functions. FNC 4 is reserved for future use.

- G -

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.

- H -

HeNe Laser
A helium neon laser commonly used in bar code scanners.

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.

- 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.

- J -

- K -

- 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.

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.

- M -

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.

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

- 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.

- 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.

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.

- P -

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.

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.

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.

- 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."

- R -

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

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.

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.

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

- S -

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 AS/400 for
communicating with other AS/400, IBM mainframe, System/36, and System/38
systems.

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.

SNA
System Network Architecture. Enterprise communications standard developed by
IBM for linking different systems running IBM operating systems such as
OS/400 (AS/400), OS/2 (PC), AIX (RS/6000), etc.

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.

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.

- T -

T&A
Time and 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.

- U -

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.

- 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.

- W -

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.

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

- X -

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

- Y -

- Z -

- # -