Rockwell Automation 2755 AdaptaScan Bar Code Readers - Manual (Page 28)

Installation Considerations 2–2
The Reader supports raster and linear scanning. The Reader can be
mounted in either a step ladder or picket fence orientation with
respect to the bar code label. The type of scanning and the
placement of the bar code label usually determines the orientation.
Picket Fence Orientation Step Ladder Orientation
Reader Mounted
Above Conveyor
Reader Mounted
On Side of Conveyor
Reader Mounted
Above Conveyor
Reader Mounted
On Side of Conveyor
When the labels pass the Reader in a step ladder orienta-
tion, a linear scan is preferred. The beam scans the label
as it passes. The number of scans per label depends
upon the label size, scan rate and the conveyor speed. If a linear scanning Reader is aligned parallel with the long axis of
a picket fence label, the same strip of label is scanned repeatedly.
Because of this, picket fence applications usually use a raster
scan.
Picket Fence or
Step Ladder Orientation