Datalogic AV7000, Reference Manual

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INTRODUCTION
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1.3 IMAGE ACQUISITION
Each barcode reader contains two distinct groups of devices:

The acquisition device or "camera." This part of the AV7000 has to work in strict real time
to acquire the best possible images.

The decoding device or “decoder." This part of the AV7000 interprets the data received
through the camera.
The Standard AV7000 barcode reader contains both the camera and the decoder.
As already mentioned, the camera needs three kinds of external sensors:

Speed Sensor: At all times the camera needs to know the speed of the objects to be
acquired. The speed sensor is usually an encoder/tachometer connected to the belt, an
internal software tachometer, or a PDG100 Speed Detector when using a tilt-tray or cross-
belt system.

Height/Side Position Sensor: The focusing position is computed by the camera based
on the position of the parcel measured by a height sensor. The Datalogic sensors may be
a RangeFinder, DM3610 Dimensioner, or AREAscan™ DS2 Light Array (LCC-75xx Light
Curtain Kit).

Trigger Source: The camera needs to know when to acquire an object. In multiple
camera systems, each package has to be uniquely identified by all the cameras. For this
reason, all of the cameras in a reading station share a unique trigger source.
All the sensors are connected to the Master camera that interprets the information and
distributes it to the Slave cameras.
The start and stop of an acquisition are triggered by a start/stop event generated by the
trigger device (position sensor). T
he acquisition of a package doesn’t start when the trigger
source detects it, but with a certain delay depending on:

the distance between the trigger device and the view line at belt level

the view line angle (alpha) of the camera

the speed of the object

the height of the package
Based on the AV7000 mounting position, the unit tries to acquire one (reading angle alpha =
15°) or two faces of the parcel (alpha = +/-45°).