Siemens Sinumerik 840D sl Programming Manual page 125

Example
Program code
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, 01/2015, 6FC5398-1BP40-5BA2
8.9 Feedrate optimization for curved path sections (CFTCP, CFC, CFIN)
Comment
; Feed to first cutting depth
; Subprogram call
; Feed to second cutting depth
; Subprogram call
In this example, the contour is first produced
with CFC-corrected feedrate. During finishing,
the cutting base is also machined with CFIN.
This prevents the cutting base being damaged
at the outside radii by a feedrate that is too high.
Feed control
125