Siemens SINUMERIK 840D Function Manual page 174

V1: Feedrates
5.4 Feedrate control
MD20201 $MC_CHFRND_MODE_MASK (chamfer/rounding behavior)
Bit
0
Maximum number of empty blocks
The number of blocks without traversing information in the compensation plane (empty blocks)
permitted between two blocks with traversing information during active chamfer/rounding, is
limited. The maximum number is specified in the machine data:
MD20200 $MC_CHFRND_MAXNUM_DUMMY_BLOCKS (empty blocks for chamfer/radii)
Supplementary conditions
FLIN/FCUB
Feedrate interpolation FLIN and FCUB is not possible for chamfer/rounding.
G0
FRC/FRCM is not active when a chamfer is traversed with G0. The programming is possible in
accordance with the F value without error message.
Change G94 ↔ G95
If FRCM is programmed, the FRCM value will need to be reprogrammed like F on change
G94 ↔ G95, etc. If only F is reprogrammed and if the feedrate type FRCM > 0 before the
change, an error message will be output.
Example
Example 1: MD20201 bit 0 = 0; take feedrate from following block (default setting!)
Program code
N10 G0 X0 Y0 G17 F100 G94
N20 G1 X10 CHF=2
N30 Y10 CHF=4
N40 X20 CHF=3 FRC=200
N50 RNDM=2 FRCM=50
N60 Y20
N70 X30
N80 Y30 CHF=3 FRC=100
N90 X40
N100 Y40 FRCM=0
N110 S1000 M3
174
Value Meaning
0 The technology of the chamfer/rounding (feedrate, feedrate type, M commands, etc.) is
determined by the following block (default setting).
1 The technology of the chamfer/rounding is determined by the previous block (recom‐
mended setting).
Comment
; Chamfer N20-N30 with F=100 mm/min
; Chamfer N30-N40 with FRC=200 mm/min
; Chamfer N40-N60 with FRCM=50 mm/min
; Modal rounding N60-N70 with FRCM=50 mm/min
; Modal rounding N70-N80 with FRCM=50 mm/min
; Chamfer N80-N90 with FRC=100 mm/min
; Modal rounding N90-N100 with F=100 mm/min (dese-
lection of FRCM)
; Modal rounding N100-N120 with G95 FRC=1 mm/rev
Function Manual, 06/2019, A5E47437747B AA
Axes and spindles