Symbol LS4278 Reference Manual page 400

Glossary - 2 Symbol LS4278 Product Reference Guide
Byte. On an addressable boundary, eight adjacent binary
digits (0 and 1) combined in a pattern to represent a
specific character or numeric value. Bits are
C
CDRH. Center for Devices and Radiological Health. A
federal agency responsible for regulating laser
product safety. This agency specifies various laser
operation classes based on power output during
operation.
CDRH Class 1. This is the lowest power CDRH laser
classification. This class is considered intrinsically
safe, even if all laser output were directed into the
eye's pupil. There are no special operating
procedures for this class.
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: ( - $ : / , +).
D
Dead Zone. An area within a scanner's field of view, in
which specular reflection may prevent a successful
decode.
numbered from the right, 0 through 7, with bit 0 the
low-order bit. One byte in memory is used to store one
ASCII character.
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.
Cold Boot. A cold boot restarts a computer and closes all
running programs.
COM Port. Communication port; ports are identified by
number, e.g., COM1, COM2.
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.
Cradle. A cradle is used for charging the terminal battery
and for communicating with a host computer, and
provides a storage place for the terminal when not in
use.
Decode. To recognize a bar code symbology (e.g.,
UPC/EAN) and then analyze the content of the
specific bar code scanned.