MTS Series 793 - Manual (Page 88)

Description Callout
Compensator Feedback 8
You may select a resource for compensator feedback from:
• The Hardware Input Resources list, or
• The Station Input Resources list associated with the selected channel or Auxiliary Inputs. (You cannot
select this feedback from station resources associated with other channels.)
About compensation types
When creating a dual compensation control mode, you may select a compensation type of either Mean and
Amplitude Control, or Amplitude Control Only.
To determine which compensation type is appropriate, you should consider the following aspects of your test
setup:
• Whether or not it is appropriate to have a non-zero mean on the compensator feedback
• Transducer characteristics
• Specimen characteristics
• Fixture characteristics
For instance, if you want to apply a load to a metal or plastic specimen attached to a reaction base (for
example, mounted in a load unit), Mean and Amplitude Control is appropriate. (Non-zero mean)
If you use an accelerometer or load washer to provide compensator feedback, Amplitude Only is appropriate.
(Transducer characteristic)
If you want to apply a load to a shock absorber specimen attached to a reaction base, Amplitude Only is
appropriate. (Specimen characteristic)
If you want to apply a load to any specimen not attached to a reaction base (for example, mounted to a
free-body actuator), Amplitude Control Only is appropriate. (Fixture characteristic)
About Setpoint in a Dual Compensation Control Mode
When you select a compensation type of Mean and Amplitude, the control mode’s setpoint (which is controlled
by the Station Manager application’s setpoint control) and the function generator have the same dimension,
as shown in the following example.
88 MTS Series 793 Control Software
Station Builder