Siemens SINUMERIK 840D sl Function Manual page 1641

Table 2-2
C=...
M71
M3/4/5
or
SPOS=...
Change to spindle mode
The interpolation parameter (set 1 ... 5) is selected according to the currently valid gear step.
The feedforward control function is always activated, except for tapping with compensating
chuck.
Machine data:
MD32620 $MA_FFW_MODE (feedforward control type)
must always be not equal to 0.
Feedforward control should always be operated with the value 100% to avoid alarms being
output during positioning.
Figure 2-4
Basic logic functions: Spindles (S1)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0
Switch back to spindle mode
→ Output to PLC
Closed-loop controller enable off (by PLC)
Switch actuator (by PLC)
Switched to spindle parameter set (1-5) internally in the NC,
controller enable on (by PLC)
NC travels with spindle parameter set
Validity of parameter sets for axis and spindle modes
Detailed Description
2.1 Spindle modes
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