Siemens SINUMERIK 840D sl Programming Manual page 407

Restrictions
The functions for programming the path traversing characteristics apply regardless of the
programmed feed characteristic.
The programmed feed characteristic is always absolute regardless of G90 or G91.
Feed response FLIN and FCUB are active with
G93 and G94.
FLIN and FCUB is not active with
G95, G96/G961 and G97/G971.
Active compressor COMPON
With an active compressor COMPON the following applies when several blocks are joined to
form a spline segment:
FNORM:
The F word of the last block in the group applies to the spline segment.
FLIN:
The F word of the last block in the group applies to the spline segment.
The programmed F value applies until the end of the segment and is then approached
linearly.
FCUB:
The generated feed spline deviates from the programmed end points by an amount not
exceeding the value set in machine data $MC_COMPESS_VELO_TOL.
F=FPO(...,...,...)
These blocks are not compressed.
Job planning
Programming Manual, 03/2006 Edition, 6FC5398-2BP10-1BA0
9.5 Feedrate response (FNORM, FLIN, FCUB, FPO)
Path traversing behavior
9-41