Rockwell Automation 2755-L7, -L9 Scanners - Manual (Page 30)

Chapter 5
Operation
5–2
As shown in Figure 5.2, all scan heads come equipped with a 4 position
switch used for scan width adjustment. The switch is covered by a gasketed
1/4–20 screw.
Figure 5.2
Scan Width Adjustment Switch
To avoid an unnecessarily long beam, rotate this switch clockwise. The scan
width will reduce from full to approximately 3/4, 1/2 and 1/4. Figure 5.3
shows the scan width relative to the switch position. In each case, the usable
scan beam will be 80% of the actual beam width.
Figure 5.3
Scan Width Adjustment Switch Positions
1/4 scan beam
Full scan beam
1/2 scan beam
3/4 scan beam
Factory Setting
Reducing the scan width will often improve the scanner’s performance while
reading UPC, Code 128 and other high density labels at short ranges.
Increasing the scan width may improve the readability of low contrast labels
at maximum ranges.
Scan Width Adjustment