Siemens SINUMERIK 840DE Programming Manual page 337

DISC is programmed in steps of 1.
When DISC values greater than 0 are specified, intermediate circles are shown with a
magnified height – the result is transition ellipses or parabolas or hyperbolas.
An upper limit can be defined in machine data – generally DISC=50.
Path action, depending on DISC values and contour angle
Depending on the angle of the contour that is traversed, with acute contour angles and high
DISC values the tool is lifted off the contour at the corners. With angles of 120° and more,
the contour is traversed evenly (see adjacent table).
Corner behavior, intersection, G41, G42, G451
The tool approaches the intersection of the two equidistants, which lie in the distance
between the tool radius and the programmed contour. G451 applies only to circles and
straight lines.
Fundamentals
Programming Manual, 10.2004 Edition, 6FC5 298-7AB00-0BP1
8.10 Compensation at the outside corners (G450, G451)
Tool offsets
8-41