Reading Features; Advanced Code Reconstruction (Acr™ 4) - Datalogic DS4800 Reference Manual

READING FEATURES

7 READING FEATURES
7.1 ADVANCED CODE RECONSTRUCTION (ACR™ 4)
T he traditional way of barcode reading could be called "Linear Reading". In this case, the
la ser beam crosses the barcode symbol from its beginning to its end as shown in the
following figure:
In Advanced Code Reconstruction mode it is no longer necessary for the laser beam to cross
the label from the start to the end. With just a set of partial scans on the label (obtained using
the motion of the label itself), the scanner is able to "reconstruct" the barcode. A typical set of
p artial scans is shown in the figure below:
None of the partial scans contains the whole label. The decoder aligns each partial scan
correctly and combines them in order to obtain the entire code.
The alignment is performed by calculating the time difference from one partial scan to
another using a reference code element.
ACR4 therefore has an intrinsic abilit
a s in the examples below:
Fig ure 78 – Linear Readin
Code Direction
Figure 79 – Partial Scans
y to increase the reading percentag
ACR4™ Readable
Figure 80 – ACR4™ Readable Codes
Laser Beam
g
e of damaged codes
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