Emerson FM-3 Manuel D’Utilisation

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Tuning Procedures

When running the tests outlined in this section, the motor and drive must be operational so 
you will need to enter starting values.

If your application has less than a 10:1 inertia mismatch, the default parameter settings will 
be acceptable. If the inertial mismatch is greater than 10:1, use the following table for initial 
parameter settings.

This parameter represents friction that increases proportionally as motor velocity increases. 
The viscous friction of your system can be determined by reading the percent of continuous 
torque required to operate the loaded motor at two different speeds.

•

The most consistent readings can usually be obtained at motor speeds higher than 500 
RPM but lower test speeds can be used if necessary.

•

If your application has travel limits, it may be helpful to use an external position controller 
to prevent the axis from exceeding the machine limits. Set up a trapezoidal profile as 
shown.

•

In the procedure below, the Torque Command and Velocity Feedback parameters can be 
measured using the drive’s analog outputs, PowerTools software or an FM-P.

•

With vertical loads the test readings must be taken while traveling in the same direction.

•

An oscilloscope may be needed for systems with limited travel moves to measure the 
rapidly changing torque and velocity signals.

•

If your system’s friction changes with operating temperature, perform this procedure at 
normal operating temperature.

1.

Run the motor at the low test speed (at least 500 RPM).

2.

While at speed, note the Torque Command Actual value (TCL).

Friction

0.00

Inertia Ratio

1/3 to 1/2 Actual

Response

500/Inertia Ratio

High Performance Gains

Disabled

Feedforwards

Enabled

Line voltage

Actual Applied