HEIDENHAIN MANUALPLUS 620 - Page 873

January 2012 6.16 The Control Loop 873
Holding torque The holding torque is the torque that is required to keep a vertical axis at a
standstill.
The holding torque is given by the MANUALplus 620 through the integral-
action component of the nominal current value. In most cases the holding
torque is constant. The required holding current can therefore be fed forward
through MP_compCurrentOffset. This relieves the speed controller.
 To prevent the effect of stiction, measure the current at low speed in both
directions (e.g. 10 min
–1
).
 Calculate the holding current from the mean of the measured current values
and enter the result in MP_compCurrentOffset.
Mean:
MP_compCurrentOffset
Holding current
Available from NCK software version: 597 110-01.
Format: Numerical value
Input: –30.000 000 000 to +30 [A]
Default: 0
Access: LEVEL3
Reaction: RUN
MP_compCurrentOffset
I SOLL
1
I SOLL
2
+
2
------------------------------------
=
Note
If the ready signal (RDY) is missing from the speed encoder inputs of
vertical axes, the DSP error message
8B40 No drive release <axis> appears.
A vertical axis is defined with an entry in MP_currentOffset.