Linear Code Reading; Step-Ladder Mode - Datalogic DS4800 Reference Manual

READING FEATURES

7.2 LINEAR CODE READING

The number of scans performed on the code by the DS4800 and therefore the decoding
capability is influenced by the following parameters:
• number of scans per second
• code motion speed
• label dimensions
• scan direction with respect to code motion
At least 5 scans during the code passage should be allowed to ensure a successful read.

7.2.1 Step-Ladder Mode

If scanning is perpendicular to the code motion direction (Figure 83), the number of effective
scans performed by the reader is given by the following formula:
SN = [(LH/LS) * SS] – 2
DS4800
For example, the DS4800 (800 scans/sec.) for a 25 mm high code moving at 1250 mm/s
performs:
Where: SN = number of effective scans
LH = label height (in
LS = label movement speed in (mm/s)
SS = number of scans per second
Figure 83 - "Step-Ladder" Scanning Mode
[(25/1250) * 800] - 2 = 14 effective scans.
mm)
Direction of code
moveme nt at LS speed
LH
Laser beam
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