Rockwell Automation 2755-DM9, -DM9E High Speed Decoder - Manual (Page 159)

Glossary
G–4
start/stop character
A bar code character that provides
the scanner with start and stop
reading instructions as well as code
orientation. The start character is
normally at the left–hand end of a
horizontal code and adjacent to the
most significant character. The stop
character is normally at the
right–hand end of a horizontal code
and adjacent to the least significant
character.
string
A sequence of ASCII characters.
symbol
A combination of characters
including start/stop characters and
check characters, as required, which
form a complete scannable entity.
symbol length
The length of the symbol measured
from the beginning of the quiet area
adjacent to the start character to the
end of the quiet area adjacent to a
stop character.
U
UPC
Acronym for Universal Product
Code. The standard bar code type
for retail food packaging in the
United States.
V
valid read
A scan(s) that when processed by a
decoder, satisfies the following
parameters:
1) Belongs to an enabled symbology
2) Field length (no. of characters)
3)Fields per scan
4)Capture count
valid package
A scan (or group of scans) that is
comprised of valid reads and satisfies
the fields per package parameter.
W
word
A unit of data which contains two
bytes (16 bits).