MTS TestLine - Manual (Page 47)

Why Tuning Is Beneficial
Tuning optimizes system response by adjusting the system so that its servoloop responds accurately to
its command signal. When you tune, you are setting the stability and optimizing the response of the
servocontrol loop. Proper tuning improves the performance of your MTS system in the same way that
performing a tune-up on an automobile improves its performance.
Loop Tuning for the Example Test
In the example test you adjust tuning at two points in the procedure:
Setting Initial Values to Ensure Stability
The first point is before you install the specimen or apply hydraulic pressure to the station. The purpose
is to ensure servoloop stability. In this case you simply set tuning controls to conservative values.
Adjusting Values to Optimize Performance
The second point is after you install the specimen, but before you run the test. The purpose is to optimize
system performance with the specimen in the loop. In this case you apply a cyclic waveform command
and adjust tuning parameters so that the feedback (system response) is as close to the system command
as possible. When this is achieved, the system response is optimized for that particular specimen. If you
want to test a different specimen that has different performance characteristics, you will have to adjust
tuning values for the new specimen.
Understanding and Resolving Error Conditions
Resolving error conditions is a normal part of operating an MTS TestLine Test System. You typically identify
and resolve several error conditions during setup and testing.
Example
When you launch the Station Manager application and open a configuration, the configuration opens in
an interlocked state by design. To help you identify this error condition, the system lights the Interlock
indicator in the main window, and also writes a “Software Interlock” entry into the Message Log, To resolve
this condition, you simply click the Reset button in the Station Manager main window.
Using Application Logs to Identify Error Conditions
Both the Station Manager and MTS TestSuite Multipurpose Express applications are equipped with logs
to help you identify error conditions. These logs are your window into the state of the system, and your
information center for the source of error conditions. Each log entry is categorized with key words such as
“Warning” and “Error” to inform you if intervention is required. For quick reference, the Station Manager
application includes a Message Pane, and the MultiPurpose Express application includes an Error List
and Application Log that shows log file entries as they occur.
MTS TestLine Test System Operation | 47
Key Concepts