Rockwell Automation 5370-CVIM2 Module - Manual (Page 379)

5 Chapter Chapter 7
Inspection Tools
7–141
Example: List Processing
Some tool operations can produce, in addition to basic tool results, a variety
of multiple results. In such cases, a math tool can be configured to access and
process the multiple results either individually, or collectively, as a “list” of
values. The latter case is called “list processing.”
For instance, suppose that a window tool, using the “ Black contours ”
operation, identifies ten black objects that meet previously specified area
limits. A math tool formula can be configured to access and process each of
the ten area values individually, one step at a time. Or, if appropriate, the
formula can be configured to access all ten values (the “list”) and process
them in a single step using statistics functions (such as “
avg ”) or other
functions (such as “ sum ”).
In Figure 7.109, an example window tool is shown using the Black contours
operation. In this example, the perimeter and area parameters have been
activated in the
Target panel. As a consequence, the window, which contains
15 contours, has identified 12 of them as objects on the basis of their
perimeter and area measurements. During an inspection cycle, the window
tool calculates the perimeter and area values for each of the 12 objects.
Figure 7.109 Example: Window Tool Using Black Contours Operation
Figure 7.110 illustrates how a math tool formula could be set up for list
processing. In this example, the formula performs an “
avg ” function on the
area results from all 12 objects shown in Figure 7.109.
Figure 7.110 Example: Formula Configured For List Processing