Hardware manual

Readers Drawer Impact Reference Guide
Datalogic Automation Inc. 3-156
How the Barcode Tool Works
By default, this tool has one line segment ROI that must be drawn across all the bars of the code. (The mini-
mum bar width is two pixels.) When you train the tool, it automatically tries to determine and sets the bar-
code type (autodiscrimination). The tool fails (the Successful Read property is False) when:
• The code type cannot be determined
• The code cannot be read
• The percentage of failing scan lines exceeds the "Percent of Scan Lines That Must Pass" property
• The "Read String" property does not match the "Verify String" property
• The "Verify Optional Check Character" operation fails
Imaging Types
For optimal performance, the narrowest bars and spaces should be at least 2 pixels wide. The white pixels
should not be saturated (at 100% intensity) as this reduces accurate bar and space width measurement.
Autodiscrimination
Autodiscrimination means that the tool reads the barcode and tries to match it to one of the supported types.
If one of the types match, the "Barcode Type Found" property is set to that type.
To enable this feature, choose “Any Type” in the Barcode Type property. The feature is turned on by default.
There are two barcode types that autodiscrimination will not find - Code 39 Full ASCII and Pharmacode.
These types must be explicitly selected from the list in order to be read.
Code 39 Full ASCII: The tool automatically reads this as a standard Code 39 and explicitly decodes the
shift characters ($%/+) into the output string, so, if you see some of these characters in a Code 39 out-
put, change the Barcode Type property to Code 39 Full ASCII.
Pharmacode: This barcode type is not designed for autodiscrimination and has no distinguishing charac-
teristics. If you are using this type, you must select it in the Barcode Type property.
Autodiscrimination adds time to tool execution and increases the risk of a false positive read. When you
know the barcode type, you should select that type from the Barcode Type property list or click the “Train
Type” button in the Setup Pass/Fail panel once the barcode type has been determined.
Multiple Scan Lines
By default, the tool tries to read the code using the one line segment that you draw. You can inspect the bar-
code more thoroughly by entering a higher value for the "Number of Scan Lines" property. For example, if
you set the value to ten, the tool places ten scan lines spaced equally vertically across the code, perpendicu-
lar to the bars. Those line segments are output in the "Scan Lines" property and their pass status is output in
the "Success Per Scan Line" property. By default, all the scan lines (100 percent) must read the code suc-
cessfully, but you can allow some scan lines to fail by entering a smaller value in the "Percent of Scan Lines
That Must Pass" property.
How to set up the Barcode tool
1. Snap a good image of the desired barcode, then click the Setup tab.
Edge Point List A list of all the points found on the Line Segment ROI. Use this list to
show points on a display panel and as feedback when configuring the
Edge Detection properties.
Output Name What it is