Omron V440-F User Manual page 213

8 Advanced Settings
Grading - ISO 15415
 Overview
This section outlines the grading implementation of ISO 15415 in the reader firmware.
 Supported Symbologies
• Data Matrix ECC 200 / GS1 Data Matrix
• QR Code
 Minimum Resolution
• 6.0 Pixels Per Element Element = Nominal Cell Dimension
Configuration
 ISO 15415 Grading Serial Output
Each grade metric can be individually enabled for serial output. These outputs can be in one of three
different formats configured by the global quality output mode parameter. The mode can be config-
ured as a letter grade A-F, the actual measured metric values 0 – 100, or as a normalized grade
value score where the grade A-F is mapped from 0-100. The enabled outputs are appended to the
symbol data with the grading separator. They are appended in their order of appearance in the
grade metric section.
 ISO 15415 Grading Logic Output and Threshold 1 - 3
Each of the three logic outputs available can be configured and driven by each of the individual
grade metrics. Each output has a corresponding configuration to enable and threshold each metric
to control assertion of the output.
 Aperture
The size of the aperture to use for grading is configured as a percentage of the nominal dimension
of the symbol under evaluation. ISO 15415 is typically applied using an 80% aperture, but for con-
trolled applications a smaller aperture may be more effective for process control.
Grade Metrics
 Overall Grade
The Overall Grade is the lowest individual parameter grade. The is in accordance with the ISO
15415 specification.
 Symbol Contrast
The Symbol Contrast is the difference between the highest and lowest reflectance values over the
symbol region as measured by the aperture. Symbol Contrast measurements assume 8-bit 0 – 255
image intensity correlate to 0 – 100% reflectance. Symbol Contrast is calculated in accordance with
the ISO 15415 specification.
 Modulation
Modulation is a measure of how distinguishable dark cells are from light cells as it applies to prop-
erly decoding the codewords within the symbol. Modulation is calculated in accordance with the ISO
15415 specification.
 Reflectance Margin
Reflectance Margin is a calculation that follows the procedure of Modulation but also takes into
account individual cell state errors. Reflectance Margin is calculated in accordance with the ISO
15415 specification.
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V440-F C-Mount Code Reader User Manual