About Tuning
Model 493.02 Controller Service
Tuning
193
If You’ve Never Tuned Before
If you are unfamiliar with the tuning controls, review the following
guidelines. Before you start tuning you should:
• Define upper and lower limits for the displacement and force
sensor before you start tuning.
• Tune the displacement control mode first since no specimen is
needed.
• Note the value of the tuning control before adjusting it so you can
return it to that value if necessary.
• Make small initial tuning adjustments. If the feedback waveform
does not appear to change, increase the adjustments.
Auto tuning provides a moderate level of tuning for PIDF control
modes automatically. For more information, see “Auto tuning” on page
217.
What if you adjust
something wrong?
If you make an inappropriate adjustment, the system will go unstable
or shut down. An unstable system produces humming or screeching
sound. A system shutdown displays an error.
• If an adjustment causes the system to go unstable, quickly readjust
the control until the noise stops. If you cannot eliminate the
sound, shut down the system by pressing the Emergency Stop
switch.
Important In multi-channel configurations, pressing Emergency Stop
will shut down the HPU and all channels in the interlock
chain.
• If an adjustment causes the system to shut down, readjust the
control to the level where the system was last stable. Then reset
the system and continue tuning.
Saving the tuning
parameters
The tuning values are saved as part of the controller parameter set. The
parameter set can save one set of tuning values for each control mode.