Glossary GL-3
Discrete 2 of 5 A bin ary bar code symbology representing each character by a group of five bars, two
of which are wide. The location of wide bars in the group determines which character
is encoded; spaces are insignificant. Only numeric characters (0 to 9) and START/
STOP characters may be encoded.
EAN European Article Number. This European/International version of the UPC provides its
own coding format and symbology standards. Element dimensions are specified
metrically. EAN is used primarily in retail.
Element Generic term for a bar or space.
Encoded Area Total linear dimension occupied by all characters of a code pattern, inclu ding start/
stop characters and data.
Host Computer A computer that serves other terminals in a network, provid ing such services as
computation, database access, supervisory programs, and network control.
IEC International Electrotechnical Commission. This international agency regulates laser
safety by specifying various laser operation classes based on power output during
operation.
IEC Class 1 This is the lowest power IEC laser classification. There is no special operating
procedures for this class.
Intercharacter Gap The space between two adjacent bar code characters in a discrete code.
Interleaved Bar Code A bar code in which characters are paired together, using bars to represent the first
character and the intervening spaces to represent the second.
Interleaved 2 of 5 A binary bar code symbology representing character pairs in groups of five bars and
five interleaved spaces. Interleaving provides for greater information density. The
location of wide elements (bar/spaces) within each group determines which
characters are encoded. This continuous code type uses no intercharacter spaces.
Only numeric (0 to 9) and START/STOP characters may be encoded.
LASER - Light
Amplification by
Stimulated Emission of
Radiation
The laser is an intense light source. Light from a laser is all the same frequency, unlike
the output of an incandescent bulb. Laser light is typically coherent and has a high
energy density.
Laser Diode A ga llium-arsenide semiconductor type of laser connected to a power source to
generate a laser beam. This laser type is a compact source of coherent light.
LED Indicator A semiconductor diode (LED - Light Emitting Diode) used as an indicator, often in
digital displays. The semiconductor uses applied voltage to produce light of a certain
frequency determined by the semiconductor's particular chemical composition.
MIL 1 mil = 1 thousandth of an inch.
Misread (Misdecode) A condition which occurs when the data output of a reader or interface controller does
not agree with the data encoded within a bar code symbol.
Nominal The exact (or ideal) intended value for a specified parameter. Tolerances are specified
as positive and negative deviations from this value.
Nominal Size Standard size for a bar code symbol. Most UPC/EAN codes are used over a range of
magnifications (e.g., from 0.80 to 2.00 of nominal).
Parameter A variable that can have different values assigned to it.
Percent Decode The average probability that a single scan of a bar code would result in a successful
decode. In a well-designed bar code scanning system, that probability should
approach near 100%.