Blockwise Feed (Fb - Siemens SINUMERIK 840DE Programming Manual

Feedrate Control and Spindle Motion

7.17 Blockwise feed (FB...)

Programming
FB=<Wert> Feed motion only in one block
Parameters
FB=...=
<WERT>
Feed value
The address FB is used to define the feedrate only for the current block. After this block, the
previously active modal feedrate is active.
The feedrate is interpreted according to the active feedrate type:
• G94: feedrate in mm/min or degrees/min
• G95: feedrate in mm/rev or inch/rev
• G96: constant cutting rate
References: /FB1/ Description of Functions, V1, Feedrates
Further information:
• If no traversing motion is programmed in the block (e.g. computation block), the FB has
• If no explicit feed for chamfering/rounding is programmed, then the value of FB also
• Feedrate interpolations FLIN, FCUB, etc. are also possible without restriction.
• Simultaneous programming of FB and FD (handwheel travel with feed overlay) or F
Examples
N10 G0 X0 Y0 G17 F100
G94
N20 G1 X10
N30 X20 FB=80
N40 X30
N50 ...
...
7-46
no effect.
applies for any contour element chamfering/rounding in this block.
(modal path feedrate) is not possible.
Instead of the modal feedrate active in the previous
block, you can program a separate feedrate for this block;
in the block that follows, the previously active modal
feedrate applies.
The programmed value of FB=<Wert> must be greater than
zero.
;Initial setting
;Feedrate 100 mm/min
;Feedrate 80 mm/min
;Feedrate is 100 mm/min again
Programming Manual, 10.2004 Edition, 6FC5 298-7AB00-0BP1
Fundamentals