Siemens SINUMERIK 840D sl Function Manual page 45

MD21108 $MC_POLE_ORI_MODE
The following machine data can be used to set the response for large circle interpolation in
pole position as follows:
MD21108 $MC_POLE_ORI_MODE (behavior during large circle interpolation at pole position)
Does not define the treatment of changes in orientation during large circle interpolation unless
the starting orientation is equal to the pole orientation or approximates to it and the end
orientation of the block is outside the tolerance circle defined in the following machine data.
TRAFO5_NON_POLE_LIMIT1/2
The position of the polar axis is arbitrary in the polar position. For the large circle interpolation,
however, a specified orientation is required for this axis.
The following machine data is coded decimally.
MD21108 $MC_POLE_ORI_MODE
The units define the behavior if start orientation coincides with pole position and the decade
the behavior if start orientation is within the tolerances defined by the following machine data:
$ MC_TRAFO5_NON_POLE_LIMIT1/2
All setting values are described in "Channel-specific Machine Data".
Special Functions
Function Manual, 09/2011, 6FC5397-2BP40-2BA0
F2: Multi-axis transformations
1.2 5-axis transformation
45