Siemens SINUMERIK 840D sl Commissioning Manual page 145

Calculation of the motor speed
If the motor speed required for speed setpoint matching is not known directly, it can be
calculated as follows with reference to the required axis velocity (linear axis) or load speed
(rotary axis/spindle):
● v
● MD31060 DRIVE_RATIO_NUMERA (numerator load gearbox)
● MD31050 DRIVE_RATIO_DENOM (denominator load gearbox)
● MD31030 LEADSCREW_PITCH (leadscrew pitch) [mm/rev]
● n
● n
Checking the trim
Incorrect speed setpoint matching has a negative impact on the real loop gain of the axis.
To check speed setpoint matching it is necessary for a defined traverse velocity to compare
the actual following error with the desired following error that should be set if speed setpoint
matching is correct.
● Desired following error [ mm ]
● Traversing velocity [ m/min ]
● MD32200 POSCTRL_GAIN (K
The actual following error is shown in the axis-specific service data:
HMI:
Operating area "Diagnostics" > Service displays > Service axis/spindle
IBN CNC: NCK, PLC, drive
Commissioning Manual, 07/2007, 6FC5397-2AP10-3BA0
[mm/min]
Axis
[rpm]
Motor
[rpm]
Load
factor) [(m/min)/mm]
V
NCK start-up
10.5 Parameterize axis data
145