A programmable logic controller is an effective tool for the automation of the electro mechanical process. It
makes the use of the ladder logic. Various limitations such as wastage & inclusion of large no of labours are minimized.
Switch & level sensor are used as main sensor & PLC is used as the controller. System is classified in three modules i.e.
sensing, decision making & implementation. The PLC also communicates status of the entire system through Human
Machine Interface (HMI). Four sensors are used to detect the level of water. According to the output of the sensor PLC
take decision to operate. The ultimate decision of PLC is implemented by using through a relay switch. Automation of the
water tank is achieved using the pressure switch as a level sensor.
Keywords: PLC; Water Tank, Solenoid Valves, Ladder Logic