Rockwell Automation 2755 AdaptaScan Software - Manual (Page 215)

G–10
Publication 2755-838
scanner
An electronic device to acquire and convert reflected light from the
bars and spaces of a symbol into electrical signals for processing by
the decoder.
self-checking
A bar code or symbol using a check algorithm which can be applied
to each character to guard against undetected errors. Codes without
self-checking may employ a check digit or other redundancy in
addition to the data message.
sensor
A device that detects or measures something and generates a
corresponding electrical signal to an input circuit of a controller.
space
The lighter element of a bar code formed by the background between
bars.
spot
The undesirable presence of an area of low reflectance in a space.
start and stop characters
A bar code character that provides the scanner with information
about how the code is bounded and its orientation. The start
character is normally at the left end of a horizontal code and adjacent
to the most significant character. The stop character is normally at
the right end of the horizontal code and adjacent to the least
significant character.
step ladder orientation
A code pattern that moves perpendicular to the scan line.
string
A sequence of ASCII characters.
symbol
A combination of characters, including start and stop characters,
quiet zones, data characters and check characters required by a
particular symbology, which forms a complete, scannable entity.
symbol density
The number of characters per linear inch.