Siemens SINUMERIK 840DE Programming Manual page 145

When paths perpendicular to the active plane are also programmed, it is possible to traverse
an involute in space (comparable to helical interpolation with circles).
Programming
INVCW X... Y... Z... I... J... K... CR=...
Or
INVCCW X... Y... Z... I... J... K... CR=...
Or
INVCW I... J... K... CR=... AR=...
Or
INVCCW I... J... K... CR=... AR=...
Parameters
INVCW
INVCCW
X Y Z
I J K
CR=
AR=
Supplementary condition
Both the start point and the end point must be outside the area of the base circle of the
involute (circle with radius CR around the center point determined by I, J and K). If this
condition is not fulfilled, an alarm is generated and the program run aborted.
Fundamentals
Programming Manual, 10.2004 Edition, 6FC5 298-7AB00-0BP1
4.13 Involute interpolation (INVCW, INVCCW)
Travel on an involute in clockwise direction
Travel on an involute path in counterclockwise direction
End point in Cartesian coordinates
Center point of base circle in Cartesian coordinates
Radius of base circle
Arc angle (angle of rotation)
Programming Motion Commands
4-39