Symbol Technologies MC3000 User Manual

Page 195

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Glossary

GL-3

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 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.

boot or boot-up

The process a computer goes through when it starts. During
boot-up, the computer can run self-diagnostic tests and
configure hardware and software.

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: ( -
$ : / , +).

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 the mobile computer and erases all
user stored records and entries.

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