Abstract: The primary aim of our project is to implement virtual instrumentation controllers for cylindrical tank system. This Virtual Instrumentation PID controller implementation is possible on software called LabVIEW developed by National Instruments. We have used a Data Acquisition board (DAQ) for interfacing with the hardware. This DAQ card is product of the similar company National Instruments. An automatic control is accomplished by sensing the water level and then controlling the position of a gate valve that releases water in to the tank. The flow of project execution is: The cylindrical tank is fitted with a capacitive level sensor. This assembly takes the level readings from tank and it is converted in to 4-20 mA range, then it transmits in to the DAQ card. The designed controller will be generating the necessary controlling signal with respect to the level sensor output. The controlling signal will be acquired by DAQ card. The DAQ card transfers it to the I / P converter which will transfer the electrical pulses 4-20mA into pneumatic signal 3-15psig to actuate the control valve.

Keywords: On –Off, PID, LabView, DAQ (Data Acquisition)