Technical Specifications

ValVue Digital Communications Software Ver. 2.80
622
GE Oil & Gas
Auto Tune
The SVI2 positioner is PID servo control device with special parameters unique to valve
positioners. Because the SVI2 can be put on a wide variety of valves, the values of the
parameters must be changed to match each valve.
The SVI2 can determine a good set of parameters automatically. When the Auto Tune
procedure is run, the SVI2 performs a series of open and closed loop tests to determine values
for P, I, D, Padjust, Beta, Position Compensation, and DeadZone. A progress dialog appears
while the autotune process is running.
The values determined should give good general operation of the valve; however, these values
are determined by a target set of performance criteria built into the SVI2. You may want
performance different than this set and may therefore want to set the PID values differently
than determined by Auto Tune. This is done on the “Calibrate Tab” on page 634.
Progres
s Dialog
Some processes that ValVue can start can be lengthy. These processes include find stops,
autotune, diagnostics, and the setup wizard. While these processes run, a dialog is provided to
show the progress and allow you to cancel the process early if necessary.
Figure 3 Progress