Rockwell Automation 2755 AdaptaScan Bar Code Readers - Manual (Page 86)

Glossary G–8
O
orientation
The alignment of bars and spaces to the scanner. Often referred to as
Picket Fence or Step Ladder.
output counter
A counter that is associated with each output condition. The counter
increments by 1 each time the condition occurs.
P
parity bit
An additional non-data bit attached to a binary word to provide a
check of the data integrity by making the sum of the number of ones
in a word always even or odd.
percent good reads
The number of successful reads per refresh period. This is valid only
when the refresh period is set to 0.
performance indicator
A bar code decoder function that counts the number of decodes
during a trigger period. When the period = 0, the performance
indicator provides the number of decodes (up to 100 attempts). Use
the performance indicator to provide a general indication of bar code
symbol quality or verify proper setup of the scanner.
performance indicator limit
A set point that will produce a discrete output if the performance
indicator falls below the set point value.
picket fence code
A code pattern in which the direction of travel of the symbol is
perpendicular to the bars and spaces of the code.
port
On a communication link, the logic circuitry or software at a station
that determines its communication parameters for a particular
communication channel.