Extending Dof With Automatic Image Settings Selection Sequence (Input Select) For Liquid Lens Models - Datalogic Matrix 300N Series Product Reference Manual

EXTENDING DOF WITH AUTOMATIC IMAGE SETTINGS SELECTION SEQUENCE (INPUT SELECT) FOR LIQUID LENS MODELS

EXTENDING DOF WITH AUTOMATIC IMAGE SETTINGS
SELECTION
SEQUENCE (INPUT SELECT) FOR LIQUID LENS MODELS
For Liquid Lens models, multiple Image Acquisition Settings can be configured and
enabled externally through a distance sensor to extend the reader's depth of field. The
specific Image Acquisition Setting Sequence is selected prior to the reading phase so
that only the correct setting (or group of settings) will be applied to the entire reading
phase.
When only two Image Acquisition Settings are used to extend DOF (one in each
sequence), this effectively allows switching DOF while keeping the lens refocusing delay
outside the reading phase.
This feature is recommended for high speed applications.
NOTE
Example
Read a 15 mil Data Matrix ECC 200 code covering a range from 140 to 320 mm at an
application speed of 1 m/s. The reading distance range is too long to be covered by a
single acquisition setting, so two acquisition settings could be used in which the first has
a Reading Distance of 195 mm and is assigned to Image Settings #1, and the second has
a Reading Distance of 300 mm and is assigned to Image Settings #2.
By assigning the Image Settings Selection to External, a proximity sensor (i.e. S3Z)
mounted at least 150 ms before the Acquisition Trigger and connected to an input (i.e.
Input 2), the correct DOF can be selected by enabling the correct sequence.
As an example, for a conveyor speed of 1 meter/second the Activation Event Trigger
(Input 2 sensor) must be placed at least 150 mm before the reading phase start (Ext.
Trigger).
The proximity sensor must be calibrated to trigger on packs in the near zone (140-215
mm) and therefore select the Sequence with Image Settings #1 (the Image Acquisition
Setting relative to the 195 mm Reading Distance). Packs farther away do not trigger the
proximity sensor and so the Sequence with Image Settings #2 is selected with the Image
Acquisition Setting relative to the 300 mm Reading Distance.
The settings overlap in the range 210-220 mm and can be read by either one.
In this way the effective reading DOF covers the 140 -320 mm distance.
Within each sequence, if more than one Image Acquisition Setting is
enabled, they will be cycled as in the case where Image Settings Selec-
tion is Automatic.
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