Siemens SINUMERIK 840D sl Programming Manual page 199

General conditions
• No Cartesian coordinates such as interpolation parameters, axis addresses, etc. may be
programmed for the selected working plane in NC blocks with polar end point coordinates.
• If a pole has not been defined with G110 ... G112, then the zero point of the current
workpiece coordinate system is automatically considered as the pole:
• Polar radius RP = 0
The polar radius is calculated from the distance between the starting point vector in the
pole plane and the active pole vector. The calculated polar radius is then saved as modal.
This applies irrespective of the selected pole definition (G110 ... G112). If both points have
been programmed identically, this radius = 0 and alarm 14095 is generated.
• Only polar angle AP has been programmed
If no polar radius RP has been programmed in the current block, but a polar angle AP,
then when there is a difference between the current position and pole in the workpiece
coordinates, this difference is used as polar radius and saved as modal. If the difference =
0, then the pole coordinates are specified again and the modal polar radius remains at
zero.
Fundamentals
Programming Manual, 09/2011, 6FC5398-1BP40-2BA0
9.3 Travel commands with polar coordinates
Motion commands
199