MTS Series 793 - Manual (Page 71)

How to Manually Tune the Control Loop
MTS Series 793 Tuning and Calibration Tuning Procedures 71
Tuning the Displacement Control Mode
A displacement control mode uses the feedback signal from an LVDT (linear
variable differential transformer). You do not need a specimen to tune a
displacement control mode.
When to tune A displacement control mode typically needs to be tuned only when recalibrated.
However, you may want to retune the displacement control mode if:
• The fixtures attached to the actuator have changed (such as grips). The main
tuning factor is a change in the mass attached to the actuator.
• Any time hydraulic system potential has changed, such as after servovalve,
hose, or pump replacement.
• You want to fine tune the control mode.
• The sensor range has changed.
• You feel system response should be improved or reduced.
Prerequisites
Be sure the following conditions are present before you begin tuning the
displacement control mode:
• Hydraulic pressure is off
• The specimen is not installed
Procedure
This basic displacement tuning procedure should work for most applications—
consider it a guideline. You should be familiar with the background information
presented in this chapter so you can modify the following procedure for your
specific system.
1. Select the Tuning access level.