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FM-4 Programming Module Reference Manual
Figure 49:
Tuning View
Load Group
Inertia Ratio
Inertia Ratio specifies the load to motor inertia ratio and has a range of 0.0 to 50.0. If the exact inertia is unknown, a
conservative approximate value should be used. If you enter an inertia value higher than the actual inertia, the resultant motor
response will tend to be more oscillatory.
Friction
This parameter is characterized in terms of the rate of friction increase per 100 motor RPM. If estimated, always use a
conservative (less than or equal to actual) estimate. If the friction is completely unknown, a value of zero should be used. A
typical value used here is less than one percent.
Low Pass Filter Group
The Low Pass Filter will reduce machine resonance due to mechanical coupling and other flexible drive/load components by
filtering the command generated by the velocity loop.
Low Pass Filter Enable Check box
When this check box is selected it enables a Low Pass Filter to be applied to the output of the velocity command before the
torque compensator.
Low Pass Frequency
This parameter defines the Low Pass Filter cut-off frequency. Signals exceeding this frequency will be filtered at a rate of 40
dB per decade. The default value is 600Hz.
Tuning Group
Response
The Response adjusts the velocity loop bandwidth with a range of 1 to 500 Hz. In general, it affects how quickly the drive
will respond to commands, load disturbances and velocity corrections. A good value to start with (the default) is 50 Hz. The
maximum value recommended is 80 Hz.
Enable Feedforwards Check Box
When feedforwards are enabled, the accuracy of the Inertia and Friction paramete rs is very important. If the Inertia parameter
is larger than the actual inertia, the result could be a significant overshoot during ramping. If the Inertia parameter is smaller
than the actual inertia, following error during ramping will be reduced but not eliminated. If the Friction parameter is greater
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