Rockwell Automation 5370-CVIM2 Module - Manual (Page 185)

Chapter 6
Reference Tools
6–26
— For three–axis operations ( X
′
, X then Y and Y
′
, Y then X ), it is the X
coordinate of the intersection of lines drawn through the three
reference features, as shown in Figure 6.21 (page 6–24).
•
Y –– This returns the current Y coordinate of the principal reference
point, as follows:
— For one–axis operations ( X only and Y only ), it is the Y coordinate of
the single reference feature.
— For two–axis operations ( X then Y and Y then X ), it is the Y
coordinate of the intersection of horizontal and vertical lines drawn
through the two reference features, as shown in Figure 6.20 (page
6–23).
— For three–axis operations ( X
′
, X then Y and Y
′
, Y then X ), it is the Y
coordinate of the intersection of lines drawn through the three
reference features, as shown in Figure 6.21 (page 6–24).
•
Theta –– When a three–axis reference line tool is used, this returns the
current value of the rotation angle, in degrees, between a line connecting
the reference features on the X and X’ (or Y and Y’) and the 0
° X–axis of
the image field. When a one– or two–axis reference line tool is used,
Theta always returns
0.000 .
• nX –– This returns the change from the nominal or “learned” X
coordinate of the principal reference point.
• nY –– This returns the change from the nominal or “learned” Y
coordinate of the principal reference point.
• nTheta –– This returns the change from the nominal or “learned” value
of the rotation angle, in degrees, when a three–axis reference line tool is
used. When a one– or two–axis reference line tool is used,
nTheta always
returns 0.000 .
•
Xc –– This returns the same value as X.
•
Yc –– This returns the same value as Y.
This section discusses the reference window tool and the shift and rotation
compensation that it can provide to other tools.
Reference Window Tool: Basic Elements
A reference window tool consists of a number of basic elements, which are
described briefly as follows:
Reference window tool –– This term refers to the whole reference window
tool; that is, each instance of “
Ref. Window ” in the toolset edit panel. Each
reference window tool consists of two separately configurable “features,”
Feature A and Feature B.
Reference Window Tool