Simple Level Control Plant Model Using LabVIEW

This paper presents a design and implementation of water level control plant model used as learning aid in the level control process. The plant model consists of a differential pressure transmitter, Frequency Inverter and Proportional-Integral-Derivative (PID) Controller. The differential pressure transmitter is used for measuring liquid level in process tank, and Inverter is employed to adjust the inlet flow of the tank. The PID controller can be configured by a PID function of LabVIEW program. In addition, two flow transmitters and solenoid valve are also installed to monitor the flow rate and/or cascade additional control loop in the future. The procedure to implement the plant model are divided into 5 steps: controlling liquid level in cylinder tank with 10 cm in diameter and 40 cm in height were specified, sizing and selecting instruments needed, implementing the plant model according to the designed Piping & Instrument (P&I) diagram and Solid Work drawing, designing the control program and human machine interface (HMI) screen in LabVIEW program and the control parameters for single-loop controller modeled TTM-007, and evaluating the performances of implemented plant model. The experimental results of step changes of set point are also included and compared to the result from the plant using a commercially available single loop controller.