Siemens SINUMERIK 840D sl Programming Manual page 300

Fundamentals
2.11 Path action
Continuous-path mode with smoothing as per distance criterion (G641)
With G641, the control inserts transition elements at contour transitions. The smoothing
clearance ADIS (or ADISPOS for G0) specifies the maximum extent to which corners can be
smooth (rounded). Within this smoothing clearance, the control can ignore the configured path
and replace it with a dynamically optimized path.
Disadvantage: Only one ADIS value is available for all axes.
The effect of G641 is similar to RNDM; however, it is not restricted to the axes of the working
plane.
Just the same as G64, G641 works with lookahead predictive velocity control. Smoothing
blocks with a high degree of curvature are approached with a reduced velocity.
Example:
Program code
N10 G641 ADIS=0.5 G1 X... Y...
300
Comment
; The smoothing block must begin no more than
0.5 mm before the programmed end of the block
and must finish 0.5 mm after the end of the
block. This setting remains modal.
Programming Manual, 12/2019, 6FC5398-2EP40-0BA0
NC programming