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Rockwell Automation 2755-G3-W_G6-W Scanner with Wedge Option User Manual

Page 82

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Glossary

G–3

horizontal bar code: A bar code or symbol presented in a
manner that its overall length dimension is parallel to the
horizon. The bars look like a picket fence.

Interleaved 2 of 5: A symbology in which characters are
paired together using bars to represent odd number char-
acters and spaces to represent even number characters.

ladder orientation: See vertical bar code.

modulus 43 check character: Used in Code 39 for data
security in addition to the builtin self-checking characters.
The check-character is the modulus 43 sum of all of the
character values in a given message and is the last
character in the code.

orientation: The alignment of bars and spaces to the
scanner. Often referred to as vertical (ladder) or
horizontal (picket fence).

parity bit: An additional non-data bit attached to a binary
word to provide a check of the data integrity by making
the sum of the number of ones in a word always even
or odd.

picket fence code: See horizontal bar code.

scan: The search for a symbol or marks which are to be
optically recognized.

scan area: The area intended to contain a bar code
symbol.

scanner: A device that optically scans bar code symbols
and converts the optical information into digital or analog
form and sends it to a decoder.

self-checking: A bar code or symbol using a checking
algorithm which can be applied to each character to guard
against undetected errors. Codes that are not
self-checking may employ a check digit or other
redundancy in addition to the data message.

space: The lighter element of a bar code formed by the
background between bars.