Glossary

A

Aperture. The opening in an optical system defined by a lens or baffle that estab lishes the field of view.
API. An interface by means of which one software component communicates with or controls another. Usually used to refer
to services provided by one software component to another, usually vi a software interrupts or function calls
Application Programming Interface. See API.
ASCII. American Standard Code for Information Interchange. A 7 bit-plus-parity c ode representing 128 letters, numerals,
punctuation marks and control characters. It is a standard data transmis sion code in the U.S.
Autodiscrimination. The ability of an interface controller to determine the code type of a scanned bar code. After this
determination is made, the information content is decoded.

B

Bar. The dark element in a printed bar code symbol.
Bar Code. A pattern of variable-width bars and spaces which represents numeric or alphan umeric data in machine-readable
form. The general format of a bar code symbol consists of a leading mar gin, start character, data or message character,
check character (if any), stop character, and trailing margin. Within this framework, each recognizable symbology uses
its own unique format. See Symbology.
Bar Code Density. The number of characters represented per unit of measurement (e.g., cha racters 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 trail ing edge of the same
bar.
BIOS. Basic Input Output System. A collection of ROM-based code with a standard API used to interface with standard PC
hardware.