Siemens SINUMERIK 840DE Programming Manual page 178

Programming Motion Commands
4.22 Chamfer, rounding (CHF, CHR, RND, RNDM, FRC, FRCM)
If FRC/FRCM is not programmed, then the normal path feedrate F is applicable.
Programming
CHF=...
Or
CHR=...
Or
RND=...
Or
RNDM=...
Or
FRC=...
Or
FRCM=...
Parameters
CHF=...
CHR=...
RND=...
RNDM=...
FRC=...
FRCM=...
Feed FRC (non-modal), FRCM (modal)
To optimize surface quality, it is possible to program a separate feedrate for the
chamfer/rounding contour elements. FRC is non-modal and FRCM is modal, see examples.
4-72
Chamfer the contour corner
Value = Length of the chamfer (unit of measurement according to
G70/G71)
Chamfer the contour corner
Programming the chamfer in the original direction of movement.
Value = width of chamfer in direction of motion (unit of
measurement as above)
Round the contour corner
Value = Radius of the rounding (unit of measurement according
to G70/G71)
Modal rounding: Rounding several consecutive contour corners in
the same way.
Value = Radius of the roundings (unit of measurement according
to G70/G71)
Rounding is deactivated with RNDM=0.
Non-modal feedrate for chamfer/rounding
Value = feedrate in mm/min (G94) or mm/rev (G95); FRC > 0
Modal feedrate for chamfer/rounding
Value = feedrate in mm/min (G94) or mm/rev (G95)
=0: The feedrate programmed under F for the chamfer/rounding is
active.
Programming Manual, 10.2004 Edition, 6FC5 298-7AB00-0BP1
Fundamentals