Design a PLC program to control the level of a water storage tank by turning a discharge pump ON and OFF based on Low and High levels.

Logic :

• Auto : if Auto Mode selected in Local Control Panel, then pump will be logically controlled based on Low Level Switch and High Level Switch
• Manual : if Manual Mode Selected in Local Control Panel, then irrespective of Low Level Switch & High Level Switch Status, Pump will be controlled manually using ON/OFF button in Local Control Panel.
• When the water level reaches low level then pump will be stopped.
• if the level of the water reaches high point, the pump will started so that the water can be drained and thus lowering the level.
• Indication Panel : This panel contains LED’s to show the status of the water level control. It has Pump Running, Low Level & High Level Signals
• If pump is running then the Pump Running status lamp will be ON.
• if Low Level Switch activated then Low Level Status lamp will be ON.
• if High Level Switch activated then High Level Status lamp will be ON.

Ladder Logic :

Manual Mode Selected, OFF Position and Water at Low Level

Manual Mode Selected & Water between Low & High Levels

Auto Mode Selected & High Level Switch Activated