Siemens SIMATIC MV500, Operating Instructions Manual, Page: 61 / 294

Image processing
3.2 Code verification
SIMATIC MV500
Operating Instructions, 03/2021, C79000-G8976-C494-05
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3.2.5.5 Siemens DPM
In Siemens DPM verification, you can select the quality features to be used and configure the
levels "Good", "Fair", and "Poor" for each individual quality feature.
The range of options for verification is ideal for process control in data matrix applications in
which no public standard needs to be adhered to.
Note
Quality features disabled in the default setting
The quality features "Symbol contrast" and "Cell size" are not enabled in the default setting
because these quality features are of limited significance for direct part marks.
The quality features can be activated in the WBM.
Quality features
• Cell size:
The overall width divided by the number of columns or the overall height divided by the
number rows. The value output is the cell size in mils (milli-inches). The assignment to the
quality level is based on the number of pixels (see table below).
• Center offset:
Measurement of the offset of the cell center to the center of the ideal grid starting at the
four corners of the codes.
• Size offset:
Measurement of the difference in cell sizes compared with each other.
• Cell modulation:
Measurement of the uniformity of the reflection values of the dark cells compared with
the light cells.
• Border match:
Percentage of border cells that match the pattern formed by the four borders of the data
matrix.
• Symbol contrast:
Difference between the average reflectance of the lightest pixels and the darkest pixels.
• Axial non-uniformity:
Difference between the height and width relative to the rows and columns.
• Print growth:
Positive or negative size ratio of the printed cells relative to the ideal grid.