Motorola Symbol MS4404 Integration Manual page 295

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.
Light Emitting Diode. See LED.
Liquid Crystal Display (LCD). A display that uses liquid crystal sealed between two glass plates. The crystals are excited
by precise electrical charges, causing them to reflect light outside according to their bias. They use little electricity and
react relatively quickly. They require external light to reflect their information to the user.
M
Matrix Symbols. A 2-dimensional array of regular polygon shaped cells where the center-to-center distance of adjacent
elements is uniform. The arrangement of the cells represents data and/or symbology functions. Matrix symbols may
include recognition patterns that do not follow the same rule as the other elements within the symbol (i.e., Data Matrix
and Maxicode).
MIL. 1 mil = 1 thousandth of an inch; a unit of measure often used to quantify bar code printing and scanning dimensions.
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.
Module. (1) The narrowest nominal width unit of measure in a symbol. In certain symbologies, element widths are specified
as multiples of 1 module. Equivalent to X dimension; or (2) a single cell in a matrix symbology used to encode 1 bit of
data. In Maxicode, the module shape is a regular hexagon. In Data Matrix, the module shape is nominally square. In
PDF417, the module shape is a regular rectangle. In bar code symbologies, the module shape is a regular rectangle.
Module Check Digit or Character. A character within the symbol data field calculated using modular arithmetic that is used
for error detection. The calculated character is determined by applying a code algorithm to the data field contents. See
Check Character.
Moving Beam Bar Code Reader. A device where scanning motion is achieved by mechanically moving the optical
geometry.
MRD. Minimum reflectance difference: a formula that is used to determine if there is an adequate difference between
absorbed and reflected light.
N
Nanometer. Unit of measure used to define the wavelength of light that is equal to 10
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).
Non-Contact Reader/Scanner. Bar code readers requiring no physical contact with the printed symbol.
Glossary - 7
-9
meter.