Rockwell Automation 2755-L7, -L9 Scanners - Manual (Page 31)

Chapter 5
Operation
5–3
1. Remove power to the scan head. In doing so, you will avoid harmful
direct eye contact with the beam.
2. Remove the gasketed 1/4–20 screw to expose the scan width
adjustment screw.
3. Using the adjustment tool provided with the scanner, carefully rotate
the switch to the desired position.
4. Replace the gasketed 1/4–20 screw.
5. Apply power to the scan head.
Raster scan heads are equipped with stepping raster motors designed to move
in synchronization with the scan sweep. The raster motor takes one step on
each reverse scan. Each step deflects the scan beam by approximately .3
°
.
The approximate spacing between the raster lines can be expressed as:
N (Lines/Inch) = 191/D
D = Distance from scan head to Label. For maximum accuracy,
measure from the label center to the scan window, then add
1.28 inches (3.25 cm).
Figure 5.4 shows the Raster Height Adjustment Switch, which is covered by a
gasketed 1/4–20 screw.
Figure 5.4
Raster Height Adjustment Switch
Scan Width Adjustment
Procedure
Raster Head Adjustment