Rockwell Automation 2755 Undecoded Hand-Held Scanner - Manual (Page 37)

G–6
Publication 2755-6.1
S
Scanner
An electronic device used to scan bar code symbols and produce a
digitized pattern that corresponds to the bars and spaces of the
symbol. Its three main components are:
1. Light source (laser or photoelectric cell) - illuminates a bar
code.
2. Photodetector - registers the difference in reflected light
(more light reflected from spaces).
3. Signal conditioning circuit - transforms optical detector
output into a digitized bar pattern.
Scanning Mode
The scanner is energized, programmed, and ready to read a bar code.
Scanning Sequence
A method of programming or configuring parameters for a bar code
reading system by scanning bar code menus.
Self Checking Code
A symbology that uses a checking algorithm to detect encoding
errors within the characters of a bar code symbol.
Start / Stop Character
A pattern of bars and spaces that provides the scanner with start and
stop reading instructions and scanning direction. The start and stop
characters are normally to the left and right margins of a horizontal
code.
Symbol
A scannable unit that encodes data within the conventions of a
certain symbology, usually including start/stop characters, quiet
zones, data characters, and check characters.
Symbology
The structural rules and conventions for representing data within a
particular bar code type (e.g. UPC/EAN, Code 39).