Programmable Feedrate Characteristics - Siemens SINUMERIK 840D Function Manual

V1: Feedrates
5.4 Feedrate control
DRF offset
The DRF offset cannot be activated for a selected fixed feedrate.
5.4.7

Programmable feedrate characteristics

Function
To permit flexible definition of the feedrate characteristic, the feedrate programming according
to DIN 66025 has been extended by linear and cubic characteristics.
The cubic profiles can be programmed directly or as an interpolating spline.
Programming
You can program the following feedrate profiles:
● FNORM
Behavior in accordance with DIN 66025 (default setting).
An F-value programmed in the block is applied over the entire path of the block, and is
subsequently regarded as a fixed modal value.
● FLIN
An F value programmed in the block is traversed linearly over the path from the current value
at the beginning of the block to the end of the block, and is subsequently regarded as modal
value.
● FCUB
The non-modal programmed F values (relative to the end of the block) are connected by a
spline. The spline starts and ends tangentially to the previous or following feedrate setting.
If the F address is missing in one block, then the last programmed F value is used.
● FPO
The F address [syntax: F=FPO(...,...,...)] designates the characteristic of the
feedrate via a polynomial from the current value to the end of the block in which it was
programmed. The end value is treated as modal from there onwards.
Parameterization
If FLIN and FCUB are used in connection with compression COMPON, a tolerance can be
defined for the path feedrate:
MD20172 $MC_COMPRESS_VELO_TOL (max. permissible deviation of the path feedrate
with compression)
Boundary conditions
FLIN/FCUB
The path velocity profile programmed with FLIN or FCUB is not active together with revolutional
feedrate for G95 as well as with constant cutting rate with G96/G961 and G97/G971.
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Axes and spindles
Function Manual, 06/2019, A5E47437747B AA