Non-Modal Feedrate (Fb) - Siemens SINUMERIK 840D sl Programming Manual

7.11

Non-modal feedrate (FB)

Function
The "Non-modal feedrate" function can be used to define a separate feedrate for a single
block. After this block, the previous modal feedrate is active again.
Syntax
FB=<value>
Significance
FB:
<VALUE>:
Note
If no traversing motion is programmed in the block (e.g. computation block), the FB has no
effect.
If no explicit feedrate for chamfering/rounding is programmed, then the value of FB also
applies for any chamfering/rounding contour element in this block.
Feedrate interpolations FLIN, FCUB, etc. are also possible without restriction.
Simultaneous programming of FB and FD (handwheel travel with feedrate override) or F
(modal path feedrate) is not possible.
Example
Program code
N10 G0 X0 Y0 G17 F100 G94
N20 G1 X10
N30 X20 FB=80
N40 X30
...
Fundamentals
Programming Manual, 09/2011, 6FC5398-1BP40-2BA0
Feedrate for current block only
The programmed value must be greater than zero.
Values are interpreted based on the active feedrate type:
• G94: feedrate in mm/min or degrees/min
• G95: feedrate in mm/rev or inch/rev
• G96: Constant cutting rate
Comment
; Initial setting
; Feedrate 100 mm/min
; Feedrate 80 mm/min
; Feedrate is 100 mm/min again.
Feed control
7.11 Non-modal feedrate (FB)
151