Symbol SE 2223, Integration Manual

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Glossary-5
Glossary
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.
Random Access
Memory (RAM) Memory devices where any location in memory can be accessed as quickly
as any other location.
Reflectance Amount of light returned from an illuminated surface.
Resolution The narrowest element dimension which can be distinguished by a
particular reading device or printed with a particular device or method.
RTS Request to send.