MTS Series 793 Application - Manual (Page 66)

MTS MultiPurpose TestWare®
About Setpoint Use with MPT Test Procedures
MPT Options Editor 66
About Setpoint Use with MPT Test Procedures
General
considerations
There are many reasons that you may or may not want the operator to have the
ability to change the Station Manager application’s setpoint control while the test
procedure is running.
In general, you typically want to prevent the operator from changing the setpoint
when performing tests that include control mode switches. So when you are
creating test procedures that perform control mode switches, select Disable and
Reset for the Setpoint control.
Differences between
Setpoint Enabled and
Relative Endlevels
The Setpoint Enabled setting on the MPT Options Editor applies to the
execution of the entire test procedure. The Relative Endlevels setting available
in the Command tab of some command processes applies only to the execution
of the associated process.
Setpoint Enabled is typically used in applications where the test designer wants
to give the operator control of the reference level while the test is in progress.
These applications also typically run the entire test in a single control mode.
"Relative Endlevels" instructs that specific process to interpret its endlevels
relative to the segment generator's command when the process begins. This does
not give the operator the ability to change the reference point dynamically. It is
often used after a modeswitch. For example, ramp in load control to particular
load, then switch to displacement and ramp 3 mm relative to where the actuator
is.
Setpoint Enabled and Relative Endlevels are independent features, and are rarely
used at the same time.It is possible to use both of these features together; their
effect is additive.
Consideration for dual
compensation control
modes
If you want to run your test procedure on a station that has a dual compensation
control mode, you need to be aware of the compensation type selected for the
control mode.
If the compensation type is Amplitude Control Only, do not disable the Station
Manager application’s setpoint with this control (that is, select Enable; do not
select Disable and Reset).
The reason is because a mode switch into a dual compensation control mode with
this type of compensation puts an offset into the setpoint (the offset provides a
“bumpless” mode switch). If you disable the setpoint (with the MPT Setpoint
control), you cannot remove the offset.