Designing of scada system for liquid level control

In this thesis, liquid level control has been achieved by processing analogous data obtained by a float-operated potentiometer. Parameters of the PID controllers in centrifuge pump drive have been calibrated with the help of designed program interface. It has been aimed and managed to enable stable working of the centrifugal pump and to maintain the desired level of liquid level. Program interface design which is necessary for SCADA system infrastructure has been designed with the program; Visual Basic Data pursuit by remote viewing has been aimed and provided using Mod-Bus protocol via USB-RS 485 converter. Two separate experimental studies have been done in order to identify PID parameters which take place in program interface. In the first study, the best PID parameters achieved by trial-and-error method and the time of liquid level?s reaching the desired reference value consistently have been observed. In the second study, the time of liquid level's reaching the desired reference value consistently has been observed using PID parameters determined in accordance with Ziegler-Nichols theorem, also mentioned before. Afterwards, these two results have been compared. Keywords : Liquid level control, SCADA, Mod-Bus, PID, Ziegler-Nichols