Wasp Bar Code Wasp Duraline WLS 8400 FZ - Manual (Page 381)

Glossary GL-11
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.
PDF417 An error correcting 2-dimensional multi-row symbol
developed in 1992 by Symbol Technologies, PDF417
symbols are constructed from 4 bars and 4 spaces
over 17 modules. The symbol size is from 3 to 90
rows. There is no specified minimum or maximum
for X or Y dimension. With at least the recommended
minimum level of error correction, the recommended
Y dimension is 3X. With less than the minimum
recommended level of error correction, the
recommended Y dimension is 4X. A quiet zone of 2X
is specified on each side of a symbol. Because of
delta decode techniques, the symbology is immune
from uniform bar width growth. PDF417 supports
cross-row scanning. The intellectual property rights
associated with PDF417 have been committed to the
public domain.
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%.
Pitch Rotation of a bar code symbol in an axis parallel to
the direction of the bars.
Plessey Code A pulse-width, modulated bar code commonly used
for shelf marking in grocery stores.