Symbol LS3478-ER, Reference Manual

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Symbol LS3478 Product Reference Guide GL-8
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 Digit ).
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.
MSI Based on the original Plessey Code, MSI, also known as
Modified Plessey, is a continuous, non-self-checking
symbology used to mark retail shelves for inventory control.
Nanometer Unit of measure used to define the wavelength of light that
is equal to 10-9 meter.
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.
Non-read The absence of data at the scanner output after an
attempted scan, which is due to no code, defective code,
scanner failure or operator error.
Omnidirectional Bar codes read in any orientation relative to the scanner.
Optical Throw The distance from the scanner face to the closest point at
which symbol can be read; also, optical throw is the
difference between range and depth of field.
Orientation The alignment of the symbol's scan path. Two possible
orientations are horizontal with vertical bars and spaces
(picket fence) and vertical with horizontal bars and spaces
(ladder).
Overhead The fixed number of characters required for start, stop and
checking in a given symbol. For example, a symbol requiring
a start, stop and 2 check characters contains 4 characters
of overhead.
Parameter A variable that can have different values assigned to it.