Siemens SINUMERIK 840Di sl Programming Manual page 301

Parameters
CFTCP
CFC
CFIN
Example of milling
In this example, the contour is first machined with a CFC-compensated feed. During
finishing, the cutting base is additionally machined with CFIN. This prevents the cutting base
from being damaged at outside radii by too high a feedrate.
N10 G17 G54 G64 T1 M6
N20 S3000 M3 CFC F500 G41
N30 G0 X-10
N40 Y0 Z-10
N50 CONTOUR1
N40 CFIN Z-25
N50 CONTOUR1
N60 Y120
N70 X200 M30
Fundamentals
Programming Manual, 11/2006, 6FC5398-1BP10-2BA0
7.9 Feedrate optimization for curved path sections (CFTCP, CFC, CFIN)
Constant feedrate on cutter center-point path.
The control keeps the feedrate constant, feed overrides are
deactivated.
Constant feed at contour (tool edge).
This function is set as the default.
Constant feed at tool edge for concave contours only, otherwise on
the cutter center path. The feedrate velocity is reduced at inside radii.
;Infeed to first cutting depth
;Subroutine call
;Infeed to second cutting depth
;Subroutine call
Feedrate Control and Spindle Motion
301