Siemens Sinumerik 840D sl Programming Manual page 122

Feed control
8.8 Feedrate with handwheel override (FD, FDA)
Further information
Traverse path axes with velocity override (FD=<velocity>)
The following conditions must be met for the part program block in which path velocity override
is programmed:
● Path command G1, G2 or G3 active
● Exact stop G60 active
● Linear feedrate G94 active
Feedrate override
The feedrate override only affects the programmed path velocity and not the velocity
component generated with the handwheel (exception: (except if feed override = 0).
Example:
Program code
N10 X... Y... F500
N20 X... Y... FD=700
Traverse positioning axes with path default (FDA[<axis>]=0)
In the NC block with programmed FDA[<axis>]=0 the feed is set to zero so that the program
cannot generate any travel movement. The programmed travel movement to the target position
is now controlled exclusively by the operator rotating the handwheel.
122
Description
; Feedrate = 500 mm/min
; Feedrate = 700 mm/min and velocity override
with handwheel.
; Acceleration from 500 to 700 mm/min in N20. The handwheel
can be used to vary the speed dependent on the direction of rotation between 0
and the maximum value (machine data).
Programming Manual, 01/2015, 6FC5398-1BP40-5BA2
Fundamentals