Galil Motion Control cadman Page 9
Chapter 2 Reference Section
2.1 Geometry Requirements
All CAD-to-DMC motion is described as a sequence of arcs and lines performed with respect
to the current controller location.
Motions can only start and stop at the endpoints of these
geometry elements. This precludes the use of circles and closed polygons, which have no
endpoints. To get around this problem, break circles into at least two arcs (more if there are
multiple start/stop points) and explode all polygons. Another geometry type which may cause
problems is the ellipse. By default, ellipses are translated by CAD-to-DMC as a series of line
segments. Depending on the application, the resulting profile may be undesirable. Exploding the
ellipse will cause CAD-to-DMC to translate it as a series of arcs, creating a smoother motion
path.
2.2 Association Principles
What is an association?
Associations, sometimes referred to as parent associations, are a means of relating drawing
elements to one another. These relationships can be used to organize the drawing's information.
Figure 9 shows some examples of associations. Associations are generally created by placing
one element near another element. The elements need not be of the same type. For example, a
text element can be associated with a line element. In fact, the CAD-to-DMC translator relies
heavily on this type of association.
