I/O

The I/O menu shows all the commands that control a wide range of real-world reader behavior, including the enabling or disabling of messages about various reader states, the configuration of the LEDs, the enabling or disabling of messages about symbol quality, and the sending of signals to external systems such as conveyors and light stacks.

 

Command parameters can be changed directly from this menu.

 

I/O Menu

 

Symbol Grading

Grading Overview

The symbol grading features presented in this document are not intended and should not be confused with symbol verification. Verifier and symbol verification is beyond the scope of this document but there are a few points worth noting to aide in understanding the features and operation provided.

 

Verifiers are systems designed to meet the rigorous standards within the verification specifications. To provide compliant verification verifier systems are not only designed with required features and functionality from the supported standard but also provide many general design features that help eliminate sources of variability that can impact measurements. In contrast readers are designed to provide maximum product flexibility for integration into systems that require reading for traceability. Key reader design specifications such as size, cost, reading range, and reading speed are a few items that drive differences between verifier and reader designs. Understanding these tradeoffs in design can help users optimize reader systems to provide better accuracy and repeatability in grading implementation.

 

Calibration

 

Compliant verification requires verifies have calibration processes. These processes are required to ensure proper references for grading metrics. The MicroHAWK provides no calibration features. It is the user’s responsibility to understand how lack of calibration may impact their grading measurements. In addition, some metrics in verification such as Minimum Reflectance in ISO 29158 are directly calculated using data only provide through calibration and have no means of representation without such a process.

 

Optical Positioning and Illumination Response

 

The presentation of the symbol to the reader can have numerous different impacts on grading performance. Verifiers are designed to provide an image with sharp focus, high resolution, and low optical distortion. These items allow verifiers to provide an environment that produces measurements with consistent results. When selecting and positioning a reader for grading it is important that the optical setup provide enough resolution to meet the minimum resolution requirements for that standard (reference standard section for resolution requirements). Although resolution is important the working distance from the imaging optics also plays a significant role in the light collection and optical distortion characteristics of the image system. Further away provides less optical distortion over the field of view but also will have significant impact on the distribution of light depending on the source of illumination. When preparing a system for a grading implementation you must take these items under consideration. First identify the allowable working distances that will provide the target symbols in focus and above the minimum required resolution. Next attempt to provide the most consistent illumination response over the inspection field at the farthest distance. The change in illumination response over distance will be very dependent on the illumination source and environment. Finally, the orientation and consistency of the symbol presentation within the field of view can also impact repeatability. If the illumination response is uneven in the field and the symbol rotated or moves throughout the field you can expect variability.

 

 

General Grading Functionality

Process Overview

 

The three specification grading functions described in this document are independent of each other as an inspection process but are dependent on the X Mode decoder being properly setup to read the symbol type provided. The grading evaluation process does not take place until a symbol has first been identified by the X Mode decoder. Once a symbol supported by an enabled grading specification has been identified by the decoder a separate grading inspection will commence. Note this inspection process can add significant processing time to the overall process and each specification requires independent processing. Furthermore, enabling any single parameter within a given specification requires the complete grading process for that specification.

 

 

Grading - ISO 15416

Overview

 

This section outlines the grading implementation for ISO 15416 available in the MicroHAWK firmware. Please refer to the free AIM guide “The Layman's Guide to ANSI, CEN and ISO/IEC Linear Bar Code Print Quality Documents” or the ISO specification documents for additional detail related print quality subject matter.

 

Supported Symbologies

 

 

 

 

 

 

 

 

Minimum Resolution

 

 

 

Usage / Notes

Illumination and the Scan Reflectance Profile

 

The accuracy and consistency of ISO 15416 grading depends greatly upon the illumination in the field of view. The ISO 15416 specification is evaluated by analyzing individual scan lines applied across the imaged symbol. These scan lines generate a signal called the scan reflectance profile which is the basis of the scan line grading methodology. This scan line grading methodology uses a fixed threshold to determine whether the signal state represents a bar or a space. Verification systems are designed to create a very flat relative signal response across the field of view. For reading a symbol there is a high tolerance to variability in the response. When grading or verifying a symbol a flat relative response is what allows the symbol to be precisely measured. Different optical configurations and illumination sources can create a wide range of responses that can impact measurements in a variety of ways.

 

To illustrate how variation that appears subtle to the eye can have a large impact on grading performance consider the following image from a standard reader using internal illumination. The scan reflectance profile for two line scans in the image are shown to the right of the imaged symbols. The larger symbol which spans the entire field of view shows dramatic differences. The spaces in the center of the symbol are providing 50% more signal response then the quiet zones at either edge of the field of view. Similarly, the smaller symbol lower in the field of view provides a much lower overall response throughout its region. Scenarios like this will create low modulation scores and differences in defect scores depending on the physical location of the defect. Worse yet if the symbol is moved within the field of view it will receive different scores. It is recommended that external illumination is used and evaluated closely for response characteristics when using ISO 15416 grading.

 

 

Figure 4 : Uneven Illumination

 

 

Synthetic Aperture

 

The synthetic aperture is a process in ISO 15416 that is applied to the image when extracting the scan line profile for grading. The aperture is an averaging process using a circular region along the scan line shown below in Figure 5.

 

 

Figure 5: Scan Line Aperture

 

 

This averaging provides a generalization of the information in the image consistent with typical reading equipment acquisition techniques. Verification systems implement the aperture based on the physical dimension of the symbol under test and the application standard guidelines such as GS1. In a reader with varying optical setup and no calibration process there is no means to know the size of the symbol under inspection. Because of this the aperture is a configurable parameter as a percentage of the narrow element of the symbol under evaluation. The default value provides a general use case similar to application standards, but it is the users responsibility to ensure this percentage matches the grading objectives. A representation of the effects of the aperture is provided in Figure 6. Selecting a larger aperture creates more of an averaging effect that is less sensitive to defects but may lower modulation.

 

 

Figure 6: Aperture Effects

 

Overall, Scan, and Individual Parameter Grades

 

The overall grade is calculated in accordance with the process defined in ISO 15416. This is often misunderstood so a review is provided here. The overall grade is an average of the individual scan grades that are applied over the inspection region. The individual scan grades are not provided but these are calculated internally as the lowest of grade of any single parameter grade evaluated in that scan or zero if the scan fails the edge determination or quiet zone requirements. The individual parameter grades provided are averages of only those parameters grades where they are evaluated. These individual average parameter grades available are not themselves part of the overall grade calculation but can be helpful information for diagnosing degrading overall grades. This creates some circumstances where the overall grade can be lower than the lowest average grade particularly when there are degrading features in the symbol from different parameters.

 

 

Configuration

15416 Grading Serial Output

 

Enable or disable the output the grading value. The output is either in value 1 to 100, or in letter grade A to F.

 

 

Aperture

 

The size of aperture to use for grading configured as a percentage of the nominal narrow element width for the symbol under evaluation. For example, if you have a 13 mil UPC symbol and you wish to grade using a 6 mil aperture you would configure the aperture to 46% (6/13 = 0.46).

 

 

Overall

 

Disabled

 

The overall grade is not formatted as part of the symbol output.

 

Enabled

 

The overall grade is formatted and attached to the decoded data as a value.

 

 

Edge Determination

 

Disabled

 

The edge determination is not formatted as part of the symbol output.

 

Enabled

 

The edge determination is formatted and attached to the decoded data as a value.

 

 

Decode

 

Disabled

 

The Decode is not formatted as part of the symbol output.

 

Enabled

 

The Decode is formatted and attached to the decoded data as a value.

 

 

Contrast

 

Disabled

 

The Contrast is not formatted as part of the symbol output.

 

Enabled

 

The Contrast is formatted and attached to the decoded data as a value.

 

 

Minimum Reflectance

 

Disabled

 

The minimum reflectance is not formatted as part of the symbol output.

 

Enabled

 

The minimum reflectance is formatted and attached to the decoded data as a value.

 

 

Minimum Edge Contrast

 

Disabled

 

The minimum edge contrast is not formatted as part of the symbol output.

 

Enabled

 

The minimum edge contrast is formatted and attached to the decoded data as a value.

 

 

Modulation

 

Disabled

 

The Modulation is not formatted as part of the symbol output.

 

Enabled

 

The Modulation is formatted and attached to the decoded data as a value.

 

 

Defects

 

Disabled

 

The Defects is not formatted as part of the symbol output.

 

Enabled

 

The Defects is formatted and attached to the decoded data as a value.

 

 

Decodability

 

Disabled

 

The Decodability is not formatted as part of the symbol output.

 

Enabled

 

The Decodability is formatted and attached to the decoded data as a value.

 

 

Quiet Zone

 

Disabled

 

The Quiet Zone is not formatted as part of the symbol output.

 

Enabled

 

The Quiet Zone is formatted and attached to the decoded data as a value.

 

 

15416 Grading Logic Output and Threshold 1 - 3

 

This parameter defines the 15416 parameter and threshold that if fallen below will assert the appropriate output. The output must be configured to output on 15416 validation before these settings apply.

 

 

Output on Overall Grade

 

Disabled

 

This will not be evaluated to drive the output.

 

Enabled

 

This will be evaluated against the corresponding threshold to drive the output.

 

 

Overall Grade Threshold

 

This is to use as a threshold for driving the output. Output will be driven if grade is under the threshold.

 

 

Edge Determination

 

Disabled

 

This will not be evaluated to drive the output.

 

Enabled

 

This will be evaluated against the corresponding threshold to drive the output.

 

 

Edge Determination Threshold

 

This is to use as a threshold for driving the output. Output will be driven if grade is under the threshold.

 

 

Decode

 

Disabled

 

This will not be evaluated to drive the output.

 

Enabled

 

This will be evaluated against the corresponding threshold to drive the output.

 

 

Decode Threshold

 

This is to use as a threshold for driving the output. Output will be driven if grade is under the threshold.

 

 

Contrast

 

Disabled

 

This will not be evaluated to drive the output.

 

Enabled

 

This will be evaluated against the corresponding threshold to drive the output.

 

 

Contrast Threshold

 

This is to use as a threshold for driving the output. Output will be driven if grade is under the threshold.

 

 

Min Reflectance

 

Disabled

 

This will not be evaluated to drive the output.

 

Enabled

 

This will be evaluated against the corresponding threshold to drive the output.

 

 

Min Reflectance Threshold

 

This is to use as a threshold for driving the output. Output will be driven if grade is under the threshold.

 

 

Min Edge Contrast

 

Disabled

 

This will not be evaluated to drive the output.

 

Enabled

 

This will be evaluated against the corresponding threshold to drive the output.

 

 

Min Edge Contrast Threshold

 

This is to use as a threshold for driving the output. Output will be driven if grade is under the threshold.

 

 

Modulation

 

Disabled

 

This will not be evaluated to drive the output.

 

Enabled

 

This will be evaluated against the corresponding threshold to drive the output.

 

 

Modulation Threshold

 

This is to use as a threshold for driving the output. Output will be driven if grade is under the threshold.

 

 

Defects

 

Disabled

 

This will not be evaluated to drive the output.

 

Enabled

 

This will be evaluated against the corresponding threshold to drive the output.

 

 

Defects Threshold

 

This is to use as a threshold for driving the output. Output will be driven if grade is under the threshold.

 

 

Decodability

 

Disabled

 

This will not be evaluated to drive the output.

 

Enabled

 

This will be evaluated against the corresponding threshold to drive the output.

 

 

Decodability Threshold

 

This is to use as a threshold for driving the output. Output will be driven if grade is under the threshold.

 

 

Quiet Zone

 

Disabled

 

This will not be evaluated to drive the output.

 

Enabled

 

This will be evaluated against the corresponding threshold to drive the output.

 

 

Quiet Zone Threshold

 

This is to use as a threshold for driving the output. Output will be driven if grade is under the threshold.

 

 

Grade Metrics

Overall Grade

 

The overall is calculated in accordance with the ISO 15416 specification. The overall grade is the average of the scan grades applied to the symbol. The individual scan grades are the lowest individual parameter grade seen during the individual scan. These scan grades are not available for output.

 

Minimum Reflectance

 

The Minimum reflectance is calculated and graded for each scan and provided for the overall grade calculation in accordance with the ISO 15416 specification. The minimum reflectance parameter grade and value provided for output is an average value for each measured scan over the entire symbol.

 

Minimum Edge Contrast

 

Contrast measurement assume 8 bit 0-255 grey correlate 0-100% reflectance The Minimum Edge Contrast is calculated and graded for each scan and provided for the overall grade calculation in accordance with the ISO 15416 specification. The parameter grade and value provided for output is an average value for each measured scan over the entire symbol.

 

Symbol Contrast

 

Contrast measurements assume 8 bit 0-255 grey correlate to 0-100% reflectance. Contrast is calculated and graded for each scan and provided for the overall grade calculation in accordance with the ISO 15416 specification. The parameter grade and value provided for output is an average value for each measured scan over the entire symbol.

 

Modulation

 

Modulation is calculated and graded for each scan and provided for the overall grade calculation in accordance with the ISO 15416 specification. The parameter grade and value provided for output is an average value for each measured scan over the entire symbol.

 

Defects

 

Defects are calculated and graded for each scan and provided for the overall grade calculation in accordance with the ISO 15416 specification. The parameter grade and value provided for output is an average value for each measured scan over the entire symbol.

 

Decodability

 

Decodability is calculated and graded for each scan and provided for the overall grade calculation in accordance with the ISO 15416 specification. The parameter grade and value provided for output is an average value for each measured scan over the entire symbol.

 

Decode

 

Decode is calculated and graded for each scan and provided for the overall grade calculation in accordance with the ISO 15416 specification. The parameter grade and value provided for output is an average value for each measured scan over the entire symbol.

 

Quiet Zone

 

Quiet zone is not an individually processed parameter within the ISO 15416 specification but is evaluated as part of the ISO graded decode parameter that feeds into the overall grade. Quiet zone is provided here as average scan result where a passing scan receives a A/4.0 grade and a fail receives a F/0.0.

 

 

Grading - ISO 15415

Overview

 

This section outlines the grading implementation for ISO 15415 available in the MicroHAWK firmware.

 

Supported Symbologies

 

 

 

Minimum Resolution

 

 

 

Configuration

 

15415 Grading Serial Output

 

Enable or disable the output the grading value.  The output is either in value 1 to 100, or in letter grade A to F.

 

 

Aperture

 

The size of aperture to use for grading configured as a percentage of the nominal narrow element width for the symbol under evaluation. For example, if you have a 15 mil UPC symbol and you wish to grade using a 10 mil aperture you would configure the aperture to 67% (10/15 = 0.67).

 

 

Overall

 

Disabled

 

The overall grade is not formatted as part of the symbol output.

 

Enabled

 

The overall grade is formatted and attached to the decoded data as a value.

 

 

Contrast

 

Disabled

 

The contrast is not formatted as part of the symbol output.

 

Enabled

 

The contrast is formatted and attached to the decoded data as a value.

 

 

Modulation

 

Disabled

 

The modulation is not formatted as part of the symbol output.

 

Enabled

 

The modulation is formatted and attached to the decoded data as a value.

 

 

Reflectance Margin

 

Disabled

 

The reflectance margin is not formatted as part of the symbol output.

 

Enabled

 

The reflectance margin is formatted and attached to the decoded data as a value.

 

 

Fixed Pattern Damage

 

Disabled

 

The fixed pattern damage is not formatted as part of the symbol output.

 

Enabled

 

The fixed pattern damage is formatted and attached to the decoded data as a value.

 

 

Axial Non-Uniformity

 

Disabled

 

The axial nonuniformity is not formatted as part of the symbol output.

 

Enabled

 

The axial nonuniformity is formatted and attached to the decoded data as a value.

 

 

Grid Non-Uniformity

 

Disabled

 

The grid nonuniformity is not formatted as part of the symbol output.

 

Enabled

 

The grid nonuniformity is formatted and attached to the decoded data as a value.

 

 

Unused ECC

 

Disabled

 

The unused ECC is not formatted as part of the symbol output.

 

Enabled

 

The unused ECC is formatted and attached to the decoded data as a value.

 

 

15415 Grading Logic Output and Threshold 1 - 3

 

This parameter defines the 15415 parameter and threshold that if fallen below will assert the appropriate output. The output must be configured to output on 15415 validation before these settings apply.

 

 

Output on Overall Grade

 

Disabled

 

This will not be evaluated to drive the output.

 

Enabled

 

This will be evaluated against the corresponding threshold to drive the output.

 

 

Overall Grade Threshold

This is to use as a threshold for driving the output. Output will be driven if grade is under the threshold.

 

 

Symbol Contrast

 

Disabled

 

This will not be evaluated to drive the output.

 

Enabled

 

This will be evaluated against the corresponding threshold to drive the output.

 

 

Symbol Contrast Threshold

 

This is to use as a threshold for driving the output. Output will be driven if grade is under the threshold.

 

 

Modulation

 

Disabled

 

This will not be evaluated to drive the output.

 

Enabled

 

This will be evaluated against the corresponding threshold to drive the output.

 

 

Modulation Threshold

 

This is to use as a threshold for driving the output. Output will be driven if grade is under the threshold.

 

 

Reflectance Margin

 

Disabled

 

This will not be evaluated to drive the output.

 

Enabled

 

This will be evaluated against the corresponding threshold to drive the output.

 

 

Reflectance Margin Threshold

 

This is to use as a threshold for driving the output. Output will be driven if grade is under the threshold.

 

 

Fixed Pattern Damage

 

Disabled

 

This will not be evaluated to drive the output.

 

Enabled

 

This will be evaluated against the corresponding threshold to drive the output.

 

 

Fixed Pattern Damage Threshold

 

This is to use as a threshold for driving the output. Output will be driven if grade is under the threshold.

 

 

Axial Non-Uniformity

 

Disabled

 

This will not be evaluated to drive the output.

 

Enabled

 

This will be evaluated against the corresponding threshold to drive the output.

 

 

Axial Non-Uniformity Threshold

 

This is to use as a threshold for driving the output. Output will be driven if grade is under the threshold.

 

 

Grid Non-Uniformity

 

Disabled

 

This will not be evaluated to drive the output.

 

Enabled

 

This will be evaluated against the corresponding threshold to drive the output.

 

 

Grid Non-Uniformity Threshold

 

This is to use as a threshold for driving the output. Output will be driven if grade is under the threshold.

 

 

Unused ECC

 

Disabled

 

This will not be evaluated to drive the output.

 

Enabled

 

This will be evaluated against the corresponding threshold to drive the output.

 

 

Unused ECC Threshold

 

This is to use as a threshold for driving the output. Output will be driven if grade is under the threshold.

 

 

Grade Metrics

Overall Grade

 

The overall is calculated in accordance with the ISO 15415 specification. The overall grade is the lowest individual parameter grade seen during the individual scan.

 

Symbol Contrast

 

Contrast measurements assume 8 bit 0-255 grey correlate to 0-100% reflectance. Symbol Contrast is calculated in accordance with the ISO 15415 specification.

 

Modulation

 

Reflectance Margin is calculated in accordance with the ISO 15415 specification.

 

Reflectance Margin

 

Reflectance Margin is calculated in accordance with the ISO 15415 specification.

 

Fixed Pattern Damage

 

Fixed Pattern Damage is calculated in accordance with the ISO 15415 specification.

 

Axial Non-Uniformity

 

Axial Non-Uniformity is calculated in accordance with the ISO 15415 specification.

 

Grid Non-Uniformity

 

Grid Non-Uniformity is calculated in accordance with the ISO 15415 specification.

 

Unused Error Correction

 

Unused Error Correction is calculated in accordance with the ISO 15415 specification.

 

 

Grading - ISO 29158

Overview

 

This section outlines the grading implementation for ISO 29158 available in the MicroHAWK firmware.

 

Supported Symbologies

 

• Data Matrix ECC200 / GS1 Data Matrix

 

Minimum Resolution

 

• 6.0 Pixels Per Element (Element = Nominal Cell Dimension)

 

 

Configuration

29158 Grading Serial Output

 

Enable or disable the output the grading value.  The output is either in value 1 to 100, or in letter grade A to F.

 

 

Overall

 

Disabled

 

The overall grade is not formatted as part of the symbol output.

 

Enabled

 

The overall grade is formatted and attached to the decoded data as a value.

 

 

Cell Contrast

 

Disabled

 

The contrast is not formatted as part of the symbol output.

 

Enabled

 

The contrast is formatted and attached to the decoded data as a value.

 

 

Cell Modulation

 

Disabled

 

The modulation is not formatted as part of the symbol output.

 

Enabled

The modulation is formatted and attached to the decoded data as a value.

 

 

Fixed Pattern Damage

 

Disabled

 

The fixed pattern damage is not formatted as part of the symbol output.

 

Enabled

 

The fixed pattern damage is formatted and attached to the decoded data as a value.

 

 

Axial Non-Uniformity

 

Disabled

 

The axial nonuniformity is not formatted as part of the symbol output.

 

Enabled

 

The axial nonuniformity is formatted and attached to the decoded data as a value.

 

 

Grid Non-Uniformity

 

Disabled

 

The grid nonuniformity is not formatted as part of the symbol output.

 

Enabled

 

The grid nonuniformity is formatted and attached to the decoded data as a value.

 

 

Unused ECC

 

Disabled

 

The unused ECC is not formatted as part of the symbol output.

 

Enabled

 

The unused ECC is formatted and attached to the decoded data as a value.

 

 

29158 Grading Logic Output and Threshold 1 - 3

 

This parameter defines the 29158 parameter and threshold that if fallen below will assert the appropriate output. The output must be configured to output on 29158 validation before these settings apply.

 

 

Output on Overall Grade

 

Disabled

 

This will not be evaluated to drive the output.

 

Enabled

 

This will be evaluated against the corresponding threshold to drive the output.

 

 

Overall Grade Threshold

 

This is to use as a threshold for driving the output. Output will be driven if grade is under the threshold.

 

 

Cell Contrast

 

Disabled

 

This will not be evaluated to drive the output.

 

Enabled

 

This will be evaluated against the corresponding threshold to drive the output.

 

 

Cell Contrast Threshold

 

This is to use as a threshold for driving the output. Output will be driven if grade is under the threshold.

 

 

Cell Modulation

 

Disabled

 

This will not be evaluated to drive the output.

 

Enabled

 

This will be evaluated against the corresponding threshold to drive the output.

 

 

Cell Modulation Threshold

 

This is to use as a threshold for driving the output. Output will be driven if grade is under the threshold.

 

 

Fixed Pattern Damage

 

Disabled

 

This will not be evaluated to drive the output.

 

Enabled

 

This will be evaluated against the corresponding threshold to drive the output.

 

 

Fixed Pattern Damage Threshold

 

This is to use as a threshold for driving the output. Output will be driven if grade is under the threshold.

 

 

Axial Non-Uniformity

 

Disabled

 

This will not be evaluated to drive the output.

 

Enabled

 

This will be evaluated against the corresponding threshold to drive the output.

 

 

Axial Non-Uniformity Threshold

 

This is to use as a threshold for driving the output. Output will be driven if grade is under the threshold.

 

 

Grid Non-Uniformity

 

Disabled

 

This will not be evaluated to drive the output.

 

Enabled

 

This will be evaluated against the corresponding threshold to drive the output.

 

 

Grid Non-Uniformity Threshold

 

This is to use as a threshold for driving the output. Output will be driven if grade is under the threshold.

 

 

Unused ECC

 

Disabled

 

This will not be evaluated to drive the output.

 

Enabled

 

This will be evaluated against the corresponding threshold to drive the output.

 

 

Unused ECC Threshold

 

This is to use as a threshold for driving the output. Output will be driven if grade is under the threshold.

 

 

ISO 29158 Metrics

Overall Grade

 

The overall grade is the minimum grade of all evaluated parameters, noting minimum reflectance is not evaluated.

 

Cell Contrast

 

Cell Contrast is calculated in accordance with the ISO 29158 specification.

 

Cell Modulation

 

Cell modulation is calculated in accordance with the ISO 29158 specification. Note the difference in the calculation for Cell Modulation versus Modulation in ISO 15415 eliminated the need for the parameter Reflectance Margin which was added to ISO 15415.

 

Fixed Pattern Damage

 

Fixed Pattern Damage is calculated in accordance with the ISO 29158 specification.

 

Axial Non-Uniformity

 

Axial Non-Uniformity is calculated in accordance with the ISO 29158 specification.

 

Grid Non-Uniformity

 

Grid Non-Uniformity is calculated in accordance with the ISO 29158 specification.

 

Unused Error Correction

 

Unused Error Correction is calculated in accordance with the ISO 29158 specification.