Rockwell Automation 2755-L7, -L9 Scanners - Manual (Page 15)

Chapter 3
Installation Considerations
3–2
As the symbols move past the scan head, they must be correctly oriented.
The laser’s line of light must cut through all the bars and spaces in one
sweep.
Laser’s line of light
cuts through the
entire symbol
For example, if the scan head is mounted so the laser beam is in the vertical
direction, then the symbol must also be mounted vertically, commonly
known as the step ladder orientation. Figure 3.2 illustrates the step ladder
orientation.
Figure 3.2
Step Ladder Orientation
Conveyor
Direction
Label
If the scan head is mounted so the beam is in the horizontal direction, the
symbol must also be in the horizontal direction. This is termed picket fence
orientation.
Refer to Figure 3.3 for an example of the scan head and symbol in a picket
fence orientation.
Figure 3.3
Picket Fence Orientation
Conveyor
Direction
Label
Positioning the Symbols
Correctly