Motorola MK1200, Руководство по продукции

Страница: 216 / 232

Glossary - 2 MK1200 MicroKiosk for CE .NET 4.2 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 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.
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.
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.
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.