Siemens SINUMERIK 840D sl Programming Manual page 207

The end point can be programmed in two ways:
1. Directly via Cartesian coordinates
2. Indirectly by specifying an opening angle (also refer to the programming of the opening
angle for circular-path programming)
If the starting point and the end point are in the plane of the basic circle, then, analogous to the
helical interpolation for circles, there is a superimposition to a curve in space.
With additional specification of paths perpendicular to the active plane, an involute can be
traversed in space (comparable to the helical interpolation for circles).
Syntax
INVCW X... Y... Z... I... J... K... CR=...
INVCCW X... Y... Z... I... J... K... CR=...
INVCW I... J... K... CR=... AR=...
INVCCW I... J... K... CR=... AR=...
Meaning
INVCW:
INVCCW:
X... Y... Z... :
I... J... K... :
CR=... :
NC programming
Programming Manual, 12/2019, 6FC5398-2EP40-0BA0
Command to travel on an involute in the clockwise direction
Command to travel on an involute in the counter-clockwise direction
Direct programming of the end point in Cartesian coordinates
Interpolation parameters for defining the center point of the basic circle
in Cartesian coordinates
Note:
The coordinate specifications refer to the starting point of the involute.
Radius of the basic circle
Fundamentals
2.9 Motion commands
207