Motorola DS9208, Руководство по продукции

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Glossary - 2 DS9208 Product Reference Guide
Bit. Binary digit. One bit is the basic unit of binary information. Generally, eight consecutive bits compose one byte of
data. The pattern of 0 and 1 values within the byte determines its meaning.
Bits per Second (bps). Bits transmitted or received.
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.
BOOTP. A protocol for remote booting of diskless devices. Assigns an IP address to a machine and may specify a boot
file. The client sends a bootp request as a broadcast to the bootp server port (67) and the bootp server responds
using the bootp client port (68). The bootp server must have a table of all devices, associated MAC addresses and
IP addresses.
bps. See Bits Per Second .
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.
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: ( -
$ : / , +).
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.