Rockwell Automation 5370-CVIM2 Module - Manual (Page 165)

Chapter 6
Reference Tools
6–6
X then Y
The X then Y reference line operation consists of two reference lines, one
that lies along the horizontal (X) axis of the image field, and one that lies
along the vertical (Y) axis. This operation is appropriate in applications
where workpiece shift is expected in both the X–axis and the Y–axis, but
with more shift occurring along the X–axis. (No workpiece rotation is
expected.)
In operation, the X then Y reference line operation evaluates the X–axis first
to determine the X–axis shift. It applies X–axis shift compensation to the
Y–axis before evaluating the Y–axis.
Figure 6.5 illustrates the X then Y reference line operation detecting X–axis
workpiece shift, applying X–axis shift to the Y–axis, then detecting Y–axis
shift in the same workpiece and applying the combined X–Y shift to the
associated window.
Figure 6.5 Example: Using an X Then Y Reference Line Operation
Y–axis with X–axis shift
compensation applied
Workpiece:
nominal position
Workpiece:
position after shift
Window:
original position
X–axis
reference line
X–axis
reference line
Y–axis
reference line
X–axis
workpiece
shift
Y–axis
workpiece
shift
Window: with X–
and Y–axis shift
compensation applied
INSPECTED
POSITION
NOMINAL
POSITION