© REA Elektronik GmbH, Teichwiesenstraße 1 D-64367 Muehltal
REA VeriCube Operating Manual Version 2.16 – 11/2020
Page 85 of 119
The DPM lighting is performed according to a preset algorithm of ISO/IEC TR 29158
when "DPM Automatic Exposure" is turned on. When "DPM Automatic Exposure" is
turned off, a manual exposure is active, which can also lead to measurement results
which are different to the ones with the automatic exposure according to the ISO/IEC
TR 29158 specification. The manual setting can be useful if the automatic is not set
up as desired or leads to no decoding. The "Duration" entry field is the manual
exposure setting.
In addition, the aperture can also be changed here. In a normal case, the aperture
will stay at the automatic setting. In this case, the aperture is set at 80% of the
module width. For all application specifications the aperture is used according to the
appropriate specification (e.g. GS1 specifications or PPN specifications for barcodes).
The aperture entry takes place in the "mil" measurement unit. Mil means milli-
inches. One inch is equal to 25.4 mm. Milli means 1/1000. Therefore, 1 mil is 25.4
µm (corresponds to 0.0254mm). The typical apertures, such as 6 mil or 10 mil,
correspond to 0.15mm or 0.25 mm.
The aperture is a subsequent formation of a light spot created by a laser. Since it is a
subsequent formation, the aperture is called "synthetic aperture".
The synthetic aperture is an image processing filtering whose purpose is to suppress
the small, irrelevant disruptions in the code. Further details about the opening can be
found in the REA training manual.
