Reverse and Direct Action of a PID Controller
Snapshot of the front panel of the simulator:
Description of the simulated system
In this simulator a level control system for a liquid tank is simulated. The control signal controls the mass outflow from the tank. The user can select the sign of the controller gain. The default PID parameter values (already set on the simulator) can be used.
Here is an instructional video where the present simulator is used as an example: Reverse or direct action in the PID controller?
The aim of this simulator is to observe the consequences of selecting wrong sign of the controller gain.
Commercial controller give the user the option to select the controller gain according to the process gain. Selecting wrong sign has dramatic concequences for the stability of the control loop.