Reading Features; Step Ladder Mode - Pepperl+Fuchs Visolux VB12 Manual

6

Reading features

The number of scans performed on the code by the VB12 scanner is a crucial
information on how precisely barcode can be read.This is influenced by the following
parameters:
• number of scans per second
• code motion speed
• label dimensions
• scan direction with respect to code motion
Typically, 5 scans should be allowed during the code passage to ensure a successful
read.
6.1

Step ladder mode

Figure 6.1 "Step ladder" scanning mode
If scanning is perpendicular to the code motion direction (Figure 6.1 - "step-ladder"
mode), the number of effective scans performed by the reader is given by the
following formula:
These symbols signify:
SN
LH
LS
SS
For example, the VB12 (350 scans/s) for a 25 mm high code moving at 500 mm/s
performs:
Subject to reasonable modifications due to technical advances.
Pepperl+Fuchs Group • Tel.: Germany (06 21) 7 76-0 • USA (330) 4 25 35 55 • Singapore 7 79 90 91 • Internet http://www.pepperl-fuchs.com
SN = [(LH/LS) x SS] - 2
= number of effective scans
= label height (in mm)
= label movement speed (in mm/s)
= number of scans per second
[(25/500) x 350] - 2 = 15 effective scans.
Barcode Scanner VB12
Reading features
Code motion direction
at LS speed
Laser beam
Copyright Pepperl+Fuchs, Printed in Germany
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