Siemens SINUMERIK 840D Function Manual page 162

V1: Feedrates
5.4 Feedrate control
With Gray coding, the override factors corresponding to the switch position must be entered in
the following machine data:
MD12070 $MN_OVR_FACTOR_SPIND_SPEED [<n>] (evaluation of the spindle override
switch)
Effectiveness of the "spindle override":
● With active G33, G34, G35:
● With active G63:
● With active G331, G332:
Reference of the spindle override
The spindle override can refer to the speed or the programmed speed limited by the machine
or setting data. The setting is realized via:
MD12080 $MN_OVR_REFERENCE_IS_PROG_FEED (override reference velocity)
Limiting the override factor
For binary-coded override factors, the maximum possible overrides for path feedrate, axis
feedrate and spindle speed can be limited:
MD12100 $MN_OVR_FACTOR_LIMIT_BIN (limit for binary coded override switch)
Override active
For overrides that have been enabled, the specified override values entered via the machine
control panel become immediately active in all operating modes and machine functions.
Override inactive
An override factor of 100% is internally effective if an override is not activated. The override
factor at the NC/PLC interface is not evaluated.
An exception is the zero setting for a binary interface and the 1st switch setting for a Gray-coded
interface. In these cases, the override factors entered at the NC/PLC interface are evaluated.
For a binary interface, the override factor is always 0%. For a Gray-coded interface, the value
entered in machine data for the 1st switch position value is output as override value. It should
be assigned the value "0".
162
Binary code
00000100
...
01100100
...
11001000
Decimal
4
...
100
...
200
Effective
Not effective
Effective
Function Manual, 06/2019, A5E47437747B AA
Override factor
0.04 ≙ 4%
...
1.00 ≙ 100%
...
2.00 ≙ 200%
Axes and spindles