Siemens SINUMERIK 840D sl Programming Manual page 297

G643:
G644:
G645:
Note
Rounding cannot be used as a substitute for smoothing (RND). The user should not make any
assumptions with respect to the appearance of the contour within the rounding area. The type
of rounding can depend on dynamic conditions, e.g. on the tool path velocity. Rounding on the
contour is therefore only practical with small ADIS values. RND must be used if a defined
contour is to be traversed at the corner.
Note
If a rounding movement initiated by G641, G642, G643, G644 or G645 is interrupted, the
starting or end point of the original traversing block (as appropriate for REPOS mode) will be
used for subsequent repositioning (REPOS), rather than the interruption point.
Example
NC programming
Programming Manual, 12/2019, 6FC5398-2EP40-0BA0
Continuous-path mode with smoothing within the defined tolerances (block-in‐
ternal)
G643 differs from G642 in that is not used to generate a separate rounding block;
instead, axis-specific block-internal rounding movements are inserted. The
rounding clearance can be different for each axis.
Continuous-path mode with smoothing with maximum possible dynamic re‐
sponse
Note:
G644 is not available with an active kinematic transformation. The system
switches internally to G642.
Continuous-path mode with smoothing and tangential block transitions within
the defined tolerances
G645 has the same effect on corners as G642. With G645, rounding blocks are
also only generated on tangential block transitions if the curvature of the original
contour exhibits a jump in at least one axis.
Fundamentals
2.11 Path action
297