Siemens SIMATIC MV500, Operating Instructions Manual, Page: 55 / 294

Image processing
3.2 Code verification
SIMATIC MV500
Operating Instructions, 03/2021, C79000-G8976-C494-05
55
• Print growth:
Positive or negative size ratio of the printed cells relative to the ideal grid. Is only
calculated as a reference, no quality grade is assigned.
• Reference decode:
Based on a binary image of the code according to ISO/IEC 16022:2006, a code is decoded
using the decoder described in the data matrix standard. If the code can be successfully
decoded, the quality grade "4" is assigned; if not, the quality grade "0".
• Symbol contrast:
Difference between the highest and lowest reflectance of the data matrix surface.
• Unused error correction:
Proportion of error correction information not used for correction of the read result.
Table 3- 3 Assignment of the numeric grade of ISO/IEC 15415 to the quality grades
Quality features
(abbreviation)
Quality grades Comment
4 3 2 1 0
Axial non-uniformity
(AN_)
≤ 0.06 ≤ 0.08 ≤ 0.10 ≤ 0.12 > 0.12 --
L/F border violation (FPD) This measurement is made in a three-stage process.
There is no direct correlation between the intermedi-
ate results and the quality grade.
--
Grid non-uniformity (GN_) ≤ 0.38 ≤ 0.50 ≤ 0.63 ≤ 0.75 > 0.75 --
Modulation (MOD) This measurement is made in a three-stage process.
There is no direct correlation between the intermedi-
ate results and the quality grade.
--
Print growth Reference only, no grading X and Y
Reference decode (RD_) pass -- -- -- Failed --
Symbol contrast (SC_) ≥ 0.70 ≥ 0.55 ≥ 0.40 ≥ 0.20 < 0.20 --
Unused error correction (UEC) ≥ 0.62 ≥ 0.50 ≥ 0.37 ≥ 0.25 < 0.25 --