Technical Specifications

ValVue Digital Communications Software Ver. 2.80
566
GE Oil & Gas
220 Read Loop Mode Displays the process controller mode for the setpoint and process
variable: either remote (measured from the primary and auxiliary
input channels respectively) or local (set by HART command and
remains constant until changed by another HART command).
141 Read Raw Data Returns information from the SVI that is useful to Masoneilan techni-
cians for diagnostic purposes. The information includes the input
current on the auxiliary input channel, the A/D values from the pres-
sure, signal, and position measurements, the D/A value of the signal
to the I/P, and the internal SVI temperature.
Auto Tune
The SVI positioner is PID servo control device with special parameters unique to valve
positioners. Because the SVI can be put on a wide variety of valves, the values of the
parameters must be changed to match each valve.
The SVI can determine a good set of parameters automatically. When the Auto Tune
procedure is run, the SVI performs a series of open and closed loop tests to determine values
for P, I, D, Padj, Beta, Position Compensation, and Dead Zone. 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 SVI. You may want
performance different than this set and may therefore want to set the PID values differently
than determined by Auto Tune. This can be done on the Calibrate tab.
Progress 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 4 Progress