A Systematic Approach to Develop PLC Program for Automation of a Backwash Water Treatment Plant

Programmable logic controllers (PLCs) are type of process control computers, which are small but relatively inexpensive, environmentally hardened, and easy to program, operate, maintain and repair. The process control computers primarily control devices such as motors, solenoids, pumps, valves, lights and heaters etc. These computers, which number in millions, are the control elements in the virtually all modern factory operations. The programmability of PLC allows for fast and easy changes in relay ladder logic to meet the changing needs of the process or driven equipment without the need for expensive and time consuming rewiring. In this paper a target to develop, simulate and implement PLC software for automation of a water treatment plant is achieved. The algorithm developed in this paper may be used to develop PLC based software for any control process