Baldor NXE100-1608Dx, Installation Manual

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5-28 Operation MN1941
5.8 Local servo axis - tuning for current control
5.8.1 Selecting servo loop gains
All servo loop parameters default to zero, meaning that the demand output will be zero at power
up. Most drive amplifiers can be set to current (torque) control mode or velocity control mode;
check that the drive amplifier will operate in the correct mode. The procedure for setting system
gains differs slightly for each. To tune an axis for velocity control, go straight to section 5.9. It is
recommended that the system is initially tested and tuned with the motor shaft disconnected from
other machinery. Confirm that the encoder feedback signals from the motor or drive amplifier
have been connected, and that a positive demand causes a positive feedback signal.
Note: The method explained in this section should allow you to gain good control of the
motor, but will not necessarily provide the optimum response without further
fine-tuning. Unavoidably, this requires a good understanding of the effect of the gain
terms.
1. In the Toolbox, click the Fine-tuning icon.
The Fine-tuning window is displayed at the
right of the screen. The main area of the Mint
WorkBench window displays the Capture
window. When tuning tests are performed,
this will display a graph representing the
response.
2. In the Fine-tuning window, click in the Axis
selection box at the top and select Axis 0
(assuming axis 0 has already been
configured as a servo axis - see section
5.5.3).
Click in the KDERIV box and enter a starting
value of 1.
Click Apply and then turn the motor shaft by
hand. Repeat this process, slowly increasing
the value of KDERIV until you begin to feel
some resistance in the motor shaft. The
exact value of KDERIV is not critical at this
stage.