Siemens sinumerik 840D sl Function Manual page 34

Detailed description
2.1 5-axis transformation
$MC_TRAFO5_POLE_LIMIT
This machine data identifies a limit angle for the 5th axis of the first MD24540
$MC_TRAFO5_NON_POLE_LIMIT_1 or the second MD24640
$MC_TRAFO5_NON_POLE_LIMIT_2 5-axis transformation with the following properties:
With interpolation through the pole point, only the fifth axis moves; the fourth axis remains in
its start position. If a movement is programmed which does not pass exactly through the pole
point, but is to pass within the tolerance defined by the following machine data in the vicinity
of the pole, a deviation is made from the specified path because the interpolation runs
exactly through the pole point.
$MC_TRAFO5_NON_POLE_LIMIT
As a result, the position at the end point of the fourth axis (pole axis) deviates from the
programmed value.
This machine data specifies the angle by which the pole axis may deviate from the
programmed value with a 5-axis transformation if a switchover is made from the
programmed interpolation to interpolation through the pole point. In the case of a greater
deviation, an error message is output and the interpolation is not executed.
Figure 2-9
28
5-axis transformation; orientation path in pole vicinity. Example for machine type 1: 2-
axis swivel head with rotary axis RA 1 (4th axis of transformation) and rotary axis RA 2
(5th axis of transformation)
Special functions: 3-Axis to 5-Axis Transformation (F2)
Function Manual, 11/2006, 6FC5397-2BP10-2BA0