Glossary - 2 LS7708 Scanner Product Reference Guide
CDRH Class 2
No additional software mechanisms are needed to conform to this limit. Laser
operation in this class poses no danger for unintentional direct human exposure.
Character
A pattern of bars and spaces which either directly represents data or indicates a
control function, such as a number, letter, punctuation mark, or communications
control contained in a message.
Character Set Those characters available for encoding in a particular bar code symbology.
Check Digit
A digit used to verify a correct symbol decode. The scanner inserts the decoded data
into an arithmetic formula and checks that the resulting number matches the encoded
check digit. Check digits are required for UPC but are optional for other symbologies.
Using check digits decreases the chance of substitution errors when a symbol is
decoded.
Codabar
A discrete self-checking code with a character set consisting of digits 0 to 9 and six
additional characters: ( - $ : / , +).
Code 128
A high density symbology which allows the controller to encode all 128 ASCII
characters without adding extra symbol elements.
Code 3 of 9 (Code 39)
A versatile and widely used alphanumeric bar code symbology with a set of 43
character types, including all uppercase letters, numerals from 0 to 9, and 7 special
characters (- . / + % $ and space). The code name is derived from the fact that 3 of 9
elements representing a character are wide, while the remaining 6 are narrow.
Code 93
An industrial symbology compatible with Code 39 but offering a full character ASCII
set and a higher coding density than Code 39.
Code Length
Number of data characters in a bar code between the start and stop characters, not
including those characters.
Continuous Code
A bar code or symbol in which all spaces within the symbol are parts of characters.
There are no intercharacter gaps in a continuous code. The absence of gaps allows
for greater information density.
Dead Zone
An area within a scanner's field of view, in which specular reflection may prevent a
successful decode.
Decode
To recognize a bar code symbology (e.g., UPC/EAN) and then analyze the content of
the specific bar code scanned.
Decode Algorithm
A decoding scheme that converts pulse widths into data representation of the letters
or numbers encoded within a bar code symbol.
Depth of Field
The range between minimum and maximum distances at which a scanner can read a
symbol with a certain minimum element width.
Discrete Code
A bar code or symbol in which the spaces between characters (intercharacter gaps)
are not part of the code.
Discrete 2 of 5
A binary bar code symbology representing each character by a group of five bars, two
of which are wide. The location of wide bars in the group determines which character
is encoded; spaces are insignificant. Only numeric characters (0 to 9) and START/
STOP characters may be encoded.
EAN
European Article Number. This European/International version of the UPC provides its
own coding format and symbology standards. Element dimensions are specified
metrically. EAN is used primarily in retail.
Element Generic term for a bar or space.
Encoded Area
Total linear dimension occupied by all characters of a code pattern, including start/
stop characters and data.
Host Computer
A computer that serves other terminals in a network, providing such services as
computation, database access, supervisory programs, and network control.
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