The objective of this work is to design Proportional Integral Derivative controller using PLC and implement it to control the speed of a DC motor. The modifications of control system have to be done frequently. In order to do so we have to come across lots of complexities. These PLC based systems removes the detailed hardware design considerations. Now PLC offers us an easy technique to modify the wiring of control system without changing its hardware. The speed of a DC motor is controlled here by varying the armature voltage using PLC as discrete state controller. Thus by...