Examples For Dpm Applications - Datalogic Matrix 300N Series Product Reference Manual

ILLUMINATORS

Examples for DPM Applications

In the example below, two Data Matrix codes etched onto a plastic reflective surface
must be read.
With all four LED sectors enabled (Example A), the code is not readable due to the LED
reflections on the code surface. With different Image Settings in which the Bottom-
Right sector is turned off (removed from the parameter combination - Example B) and
the Top-Left sector is turned off (removed from the parameter combination - Example
C), the code is illuminated by the other LED sectors without the reflections on the code
surface.
INCORRECT illumination
Please consider that, like the Diffused Red Illuminator, when using MLT-DPM Central
LED Group to illuminate surfaces with linear machining flaws, the well-lighted area
depends on the direction of the machining flaws with respect to the illuminator's LED
sectors, irrespective of the reading distance.
Clearly, this characteristic fixes the upper limit of the code dimensions compatible with
the use of the MLT-DPM. In reality, it is an actual limit of the usable part of the field of
view. Therefore, this limit must be taken into account during the feasibility analysis of
the solution, including the eventual positioning variation of the codes with respect to
the center of the reader's field of view.
The arrangement of the LED sectors allows obtaining a well-lighted area even when the
direction of the machining flaws is changed.
Refer to the following images for the dimension of lighted area illuminated by the differ-
ent LED Groups.
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MATRIX 300N
Example A
GOOD illumination on Left
Figure 109 - Color Photo of Code
Example B
GOOD illumination on
code
Example C
Right code