Glossary -5
LT 1804 Product Reference Guide: Glossary
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 = (RL - RD) / RL, where RL is the
reflectance factor of the background and RD 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.
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.
Scan Area
Area intended to contain a symbol.
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.
Space
The lighter element of a bar code formed by the background between
bars.
Specular Reflection
The mirror-like reflection of light from a surface, which can “blind” a
scanner.
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.
Substrate
A foundation material on which a substance or image is placed.
Summary of Contents for LT 1804
Page 82: ...5 27 LT 1804 Product Reference Guide Parameter Menus Baud Rate Continued 4800 1200 2400 9600 ...
Page 102: ...5 47 LT 1804 Product Reference Guide Parameter Menus Prefix Continued 0 1 2 NONE STX ...
Page 103: ...5 48 LT 1804 Product Reference Guide Parameter Menus Prefix Continued 5 3 4 6 7 ...
Page 107: ...5 52 LT 1804 Product Reference Guide Parameter Menus Suffix Continued 2 0 1 3 ...
Page 108: ...5 53 LT 1804 Product Reference Guide Parameter Menus Suffix Continued 5 4 6 7 ...
