Rockwell Automation 5370-CVIM2 Module - Manual (Page 149)

5 Chapter Chapter 5
Pick and Place Function
5–19
The function of points (D) and (E) depends on which of the two pick and
place modes you select: fixed center, or fixed ends. When you select the
fixed center mode, the center (indicated by the
•
) remains anchored in the
image field. In this mode, the diameter of the picked ring changes, while the
diameter of the other ring remains unchanged. When you select the fixed
ends mode, however, the two ends of the arc ring remain anchored in the
image field. In this mode, the radii of both rings change in lockstep, and the
spacing between them remains constant.
When you select the Fixed Center mode, the pick and place operations for an
arc ring window have the following functions:
•
Arc ring ends –– These pick and place points enable you to change the
number of radians of arc from either end of the arc ring.
•
Center of arc ring –– This pick and place point enables you to change
the position of the arc ring window within the image field.
•
Arc ring midpoint –– This pick and place point enables you to change
the radius of the picked ring (outer or inner), while the number of radians
in the picked ring remains constant (and the unpicked ring remains
unchanged).
Figure 5.18 (page 5–20) demonstrates the operation of all pick and place
operations for an arc in the fixed center mode:
•
Example 1: The right end of the arc ring is picked at point C, dragged in
a circular motion to point C
′, and then placed at point C′, thereby
decreasing the number of radians in the arc ring (the arc radius remains
the same).
•
Example 2: The center of the arc ring is picked at point A, the entire arc
is dragged to point A
′, and is then placed at point A′ (the number of
radians in the arc ring and the arc ring radius are not changed).
•
Example 3: The midpoint of the outer arc ring is picked at point D and is
dragged to point D
′, thereby uniformly increasing the radius of the outer
arc (the number of radians in the arc remains the same, and the inner arc
is unchanged).
When you select the fixed ends mode, the pick and place operations for an
arc ring have the following functions:
•
Arc ring ends; center of arc ring –– These pick and place points have
the same functions in the fixed ends mode as they do in the fixed center
mode.
•
Arc ring midpoint –– This pick and place point enables you to change
the number of radians of arc and the radius of the arc ring while the two
ends of the outer arc ring remain anchored. This point can move only in a
direction that is perpendicular to a line drawn through the two ends
(regardless of their orientation in the image field); otherwise, the
movement is restricted only by the limits of the image field.