Samson Trovis 6493 - Tuning According to the Ziegler and Nichols Method

EB 6493 EN 7-19
Start-up and conguration at the device
Proceed as follows for a P controller
1. Switch to manual mode (
).
2. In the CNTR menu, set the function -CO- C.PID = PCP.YP.
3. In the PAR menu, set the parameter KP = 0.1.
4. In the operating level, set the set point W to the required value.
Î Press
to select W and use the cursor keys ( , ). to set the value.
5. In the operating level, change the manipulated variable Y so that the controlled variable
X has the same value as the set point W (error Xd = 0).
Î Press
to select Y and use the cursor keys ( , ) to set the value.
The output Y reading is the operating point of the manipulated variable.
6. In the PAR menu, set the Y.PRE parameter to the previously determined operating point of
the manipulated variable Y.
For a P controller, every time the set point is changed, the change of the operating point is
also necessary if no steady-state error is to exist.
7. Switch to automatic mode (
).
8. In the PAR menu, step up the KP parameter until the controlled system shows a tendency
to oscillate. Every time the KP increases, let the controlled system oscillate, e.g. by mak-
ing small changes to the set point.
9. In the PAR menu, reduce the KP parameter again until the controlled system stops oscillat-
ing.
7.3.2 Tuning according to the Ziegler and Nichols method
Various tuning methods, such as the Ziegler and Nichols method, are described in control
engineering literature. This tuning method can only be applied to controlled systems in which
the controlled variable can be made to hunt. For the frequency response test, the controller
must run with P action in closed-loop operation.
Note