Philips SpeechMike - Glossary

Advanced Scanner Configuration Guide 53
Revision: 2.0 , technical changes excepted
GLOSSARY
Aperture An opening which limits the amount of light or radiation passing through an optical
system.
ASCII American Standard Code for Information Interchange. A 7 bit-plus-parity code
representing128 letters, numerals, punctuation marks, and control characters. It is
a standard data transmission code in the U.S.
Auto discrimination The ability of an interface controller to determine the code type of a scanned bar
code. After this determination is made, the information content can be decoded.
Bar The dark element in a printed bar code symbol.
Bar Code Density The number of characters represented per unit of measurement(e.g., characters
per inch).
Bar Height The dimension of a bar measured perpendicular to the bar width.
Bar Width Thickness of a bar measured from the edge closest to the symbol start character to
the trailing edge of the same bar.
Baud Rate A measure of the data flow or number of signaling events occurring per second.
When one bit is the standard “event,” this is a measure of bits per second (bps).
For example, a baud rate of 50 means transmission of 50 bits of data per second.
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.
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 through7, with bit 0 the low-order bit. One byte in memory can be used
to store one ASCII character.
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. CDRH Class 1 devices are
safe under reasonably foreseeable conditions of operation. Software and other
controls to limit exposure to laser light may be required to achieve CDRH Class 1
operation. The CDRH time base for Class 1 devices is 10,000 seconds.
CDRH Class 2 CDRH Class 2 devices may not emit more than 1 milliWatt average radiant power.
For this scan engine, additional software controls are not necessary. Eye
protection for CDRH Class 2devices is normally afforded by aversion responses,
including the blink reflex.
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 encodation in a particular bar code symbology.