PLC stands for programmable logic controller. It is a specialized industrial computer system which provides decision making capabilities by using the signals from the sensors and generates the output signals according to the inputs from the sensors and the predefined program. They have specialized input/output and interfacing capabilities. The output signals are used to operate the actuator through the control valve. The actuator direction, velocity, position and acceleration can be controlled.
It can perform functions such as timing. Sequencing and counting. They are easy to program. The programming of programmable logic controller is done by the aid of ladder diagrams. The program is stored on the memory of the controller and is non-volatile. It is a flexible device as the programming can be changed easily without changing the hard wiring.
They are sturdy as they are made to withstand vibrations and temperature changes. They are easily interfaced with sensors. They provide high degree of precision when the operation of the actuator is through them.