Siemens SINUMERIK 840D

9
08.97 Path Traversing Behavior
9.5 Feed characteristic
,
FNORM
,
FLIN
,
FCUB
,
FPO
9
840D
NCU 571
840D
NCU 572
NCU 573
840Di

Siemens AG 2000. All rights reserved
SINUMERIK 840D/840Di/810D/FM-NC Programming Guide Advanced (PGA) – 04.00 Edition
9-327
FCUB
The feed is approached according to a cubic
characteristic from the current feed value to the
programmed F value until the end of the block. The
control uses splines to connect all the feed values
programmed non-modally that have an active FCUB.
The feed values act here as interpolation points for
calculation of the spline interpolation.
Example:
N50 F1400 FCUB X50
N60 F2000 X47
N70 F3800 X52
…
Path
Feedrate
F=FPO(…,…,…)
The feed characteristic is programmed directly via a
polynomial. The polynomial coefficients are specified
according to the same method used for polynomial
interpolation.
Example:
F=FPO(endfeed, quadf, cubf)
endfeed, quadf
and
cubf
are previously
defined variables.
Path
Feedrate
endfeed:
Feed at block end
quadf:
Quadratic polynomial coefficient
cubf:
Cubic polynomial coefficient
With an active FCUB, the spline is linked tangentially
to the characteristic defined via FPO at the block
beginning and block end.
Supplementary conditions
The functions for programming the path traversing
characteristics apply regardless of the programmed
feed characteristic.