Symbol SE 923, Integration Manual

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Glossary-5
Glossary
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.
MSI Plessey A numeric-only bar code type. It can accept a variable number of digits
up to 13. MSI Plessey consists of four bars and four adjacent spaces.
Each bar\space pair consists of one information bit. A zero bit consists
of a narrow bar followed by a wide space, while one bit consist of a
wide bar followed by a narrow bar. The zero bit is one unit bar followed
by a two-unit space and the one bit is a two-unit bar followed by a one
unit space. The primary application for the MSI Plessey code is marking
of retail shelves and subsequent scanning
with portable devices for inventory purposes.
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 can be used
over a range of magnifications (e.g., from 0.80 to 2.00 of nominal).
NOTIS Editing An option that strips the start and stop characters from a decoded
Codabar symbol.
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%.
Print Contrast Signal
(PCS) Measurement of the contrast (brightness difference) between the bars
and spaces of a symbol. A minimum PCS value is needed for a bar code
symbol to be scannable. PCS = (R
L
- R
D
) / R
L
, where R
L
is the
reflectance factor of the background and R
D
the reflectance factor of the
dark bars.
Programming Mode The state in which a scanner is configured for parameter values. See
Scanning Mode .
Quiet Zone A clear space, containing no dark marks, which precedes the start
character of a bar code symbol and follows the stop character.