83
Basic setting of the process controller
Type 8792, 8793 REV.2
Enter the process set-point value as follows: (
Setting on the process level)
→
/ Select
SP
. The process set-point value is indicated on the display.
→
Select
INPUT
. The input screen for inputting the process set-point value is displayed.
→
/ Enter value
<-
Select decimal place
+
Increase value
The selected set-point value
SP
should be near the future operating point.
→
Select
OK
. Acknowledge input and return to the display of
SP.
You have entered the process actual value.
The process variable
PV
is changed according to the set-point value default based on the factory default
PID parameters.
→
Before running the
P.TUNE
function, wait until the process actual value
PV
has reached a stable state.
To observe
PV,
it is recommended to select via the arrow keys / the graphical display
SP/PV(t)
.
To be able to select the display
SP/PV(t)
it must be activated in the EXTRAS menu (see chapter
“16.1.20 EXTRAS – Setting the display”.
→
If
PV
oscillates continuously, the preset amplification factor of the process controller
KP
in the menu
P.CONTROL
→
PID.PARAMETER
should be reduced.
→
As soon as the process actual value
PV
is constant, the
P.TUNE
function can be started.
15.5.3 Starting the function
P.TUNE
WARNING
Risk of injury from uncontrolled process.
While the
P.TUNE
function is running, the control valve automatically changes the current degree of
opening and intervenes in the running process.
▶
Using suitable measures, prevent the permitted process limits from being exceeded.
For example by:
- an automatic emergency shutdown
- stopping the
P.TUNE
function by pressing the STOP key (press left or right key).
Set the
P.TUNE
function as follows:
→
Press
MENU
for 3 s. Switching from process level
setting level.
→
/ Select
P.TUNE
.
→
Select
RUN.
Hold down as long as countdown (5 ...) is running.
During the automatic adjustment the following messages are indicated on the display.
“starting process tune” -
Start self-optimization.
“identifying control process” -
Process identification. Typical process variables are determined from the
response signal to a defined stimulus.
“calculating PID parameters”
- Structure and parameters of the process controller are determined.
“TUNE ready”
- Self-optimization was successfully completed.
→
Press any key. Return to the main menu (MAIN).
→
Select
EXIT
. Switching from setting level
process level.
english
Summary of Contents for 8792
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