Siemens SINUMERIK 840D sl Function Manual page 420

T3: Tangential control
8.2 Characteristics of tangential follow-up control
Special cases
• G641 rounding is possible between two blocks, both of which move at least one of the two
leading axes of the tangentially following axis.
• G641 rounding is possible between two blocks, both of which do not move either of the
leading axes of the tangentially following axis.
In both cases, an intermediate block for the tangentially following axis is not created. An
intermediate block is not required because in the preprocessing run the rounded contour is
detected and the limit values for the following axis are calculated.
• Hidden corner in area
A corner relevant for the tangential follow-up control can be hidden in space. (The
projection of the contour on the plane defined by the two leading axes is relevant).
If there is a hidden corner in space, an intermediate block is inserted before the block
(here N6) causing the tangential jump. This intermediate block moves the following axis to
the new position. The block transition is not rounded.
Programming
N1 TANG (C, X, Y, 1)
N2 TLIFT (C)
N3 G1 G641 X0 Y0 F1000
N4 TANGON (C)
N5 X10
N6 Y10
N7 M3001.97
420
Comment
; The rotary axis is repositioned before working
off this block.
Function Manual, 09/2011, 6FC5397-2BP40-2BA0
Special Functions