Siemens SINUMERIK 840D sl Function Manual page 81

Such a situation would be treated as follows:
There is only one relevant machine data, which circles the pole as usual:
MD24540 $MC_TRAFO5_POLE_LIMIT_1 (closing angle tolerance for interpolation by pole
for 5-xis transformation)
or
MD24640 $MC_TRAFO5_POLE_LIMIT_2 (closing angle tolerance for interpolation by pole
for 5-xis transformation)
For further information about the handling of singular positions, see:
References: /PGA/ Programming Manual Work Preparation, Transformations, Cartesian PTP
travel
Example for machine type 1
Rotatable tool
Both rotary axes change the orientation of the workpiece. The orientation of the workpiece is
fixed.
2-axis swivel head with rotary axis RA 1 (4th transformation axis) and rotary axis RA 2 (5th
transformation axis)
Figure 1-20
Special Functions
Function Manual, 09/2011, 6FC5397-2BP40-2BA0
Generic 5-axis transformation; end point of orientation inside tolerance circle.
F2: Multi-axis transformations
1.8 Restrictions for kinematics and interpolation
81