Siemens SINUMERIK 840D sl Function Manual page 400

Compensations (K3)
5.6 Friction compensation (quadrant error compensation)
Good friction compensation setting
When the friction compensation function is well set, quadrant transitions are no longer
noticeable.
Figure 5-21
Amplitude too low
When the injection amplitude setting is too low, radius deviations from the programmed
radius are compensated inadequately at quadrant transitions during circularity testing.
Figure 5-22
400
Quadrant transitions with correctly set friction compensation
Amplitude too low
Function Manual, 01/2008, 6FC5397-1BP10-3BA0
Extended Functions