Siemens SINUMERIK 840D sl Function Manual page 1687

Speed default
Speed specifications from part program, FC18 or synchronized actions
are programmed in setting data:
SD43200 $SA_SPIND_S
and always programmed from the usual sources.
Read SD43200
When movement starts the speed is read from setting data:
SD43200 $SA_SPIND_S [rpm]
with the positive edge of the start signal:
DB31, ... DBX30.1 (Spindle start CW)
and
DB31, ... DBX30.2 (Spindle start CCW).
Note
Rewriting of the setting data is not activated until the next positive edge
of the start signals :
DB31, ... DBX30.1 (Spindle start CW)
and
DB31, ... DBX30.2 (Spindle start CCW)
for the current spindle speed.
The content of the setting data is only accepted with the next spindle start signal.
Gear step change and effect on speed
In the current version, no gear step change is triggered if the setpoint speed is out of the
speed range of the gear step. The usual speed limitations and the speed increase to the
setpoint speed are active.
Basic logic functions: Spindles (S1)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0
Detailed Description
2.5 Programming
77