Siemens SINUMERIK 840D Function Manual page 160

V1: Feedrates
5.4 Feedrate control
MD12030 $MN_OVR_FACTOR_FEEDRATE [<n>] (evaluation of the path feedrate override
switch)
MD12050 $MN_OVR_FACTOR_RAPID_TRA [<n>] (evaluation of the rapid traverse override
switch)
An active feedrate override acts on all path axes that are assigned to the current channel. An
active rapid traverse override has an effect on all the axes that are traversed with rapid traverse
and that are assigned to the current channel.
No rapid traverse override switch available
If there is no dedicated rapid traverse override switch, you can switch between rapid traverse
override and feedrate override. The override to be active can be selected via the PLC or
operator panel front. When rapid traverse override is active, the feedrate override values are
limited to 100%.
● When the rapid traverse override is activated via the operator panel front, the basic PLC
program:
– Transfers the selection of the feedrate override for rapid traverse on the activation signal
– Transfers the feedrate override value in the rapid traverse value
● When the rapid traverse override is selected via the PLC, the PLC user program:
– Must set the activation signal for the rapid traverse override:
– Must transfer the feedrate override value in the rapid traverse override value:
Effectiveness of the channel-specific feedrate and rapid traverse override:
● With active G33, G34, G35:
● With active G63:
● With active G331, G332:
Reference velocity for path feedrate override
The reference velocity for the "Path feedrate override via machine control panel" can be set
differently to the standard feedrate (= programmed feedrate).
MD12082 $MN_OVR_REFERENCE_IS_MIN_FEED
Axis-specific feedrate override
An enable signal and a byte for the feedrate override factor are available in the NC/PLC
interface for each positioning axis:
DB31, ... DBX1.7 (override effective)
DB31, ... DBB0 (feedrate override)
160
for the rapid traverse override:
DB21, ... DBX6.6 = DB21, ... DBX25.3
DB21, ... DBB5 = DB21, ... DBB4
DB21, ... DBX6.6 = 1
DB21, ... DBB5 = DB21, ... DBB4
Not effective
Not effective
Not effective
Function Manual, 06/2019, A5E47437747B AA
Axes and spindles