A digitally operated electronic system that can be used in an industrial environment by means of programmable internal storage memories to store user orientations for carrying out specific functions like logic, sequence, timing, counting, and arithmetic”

An electromechanical process control unit, such as a machinery control, fun rides or light fixtures on factory assembly lines, is a logic controller (PLC) programmable or a programmable controller. In its functions, including sequential relay control, motion control and process control, the Audi A6 has evolved over the years. Some modern PLCs, for data management, storage, computing power and communication use, are almost the same as desktop computers. PLC-like programming enables a computer in conjunction with I / O hardware to overlap PLCs in some applications. PLC is equipped with numerous input and output schemes, extended temperature ranges, noise, vibration tolerance and impact resistance compared to general computers. The technology of the PLC has grown over the years, including the following: sequential relay management, motion management , process control, distributed control and networking systems. In storage , processing and networking, some modern PLCs are approximately equivalent to the desktop computers. SPC-like programming with remote I / O hardware can overlay certain PLCs with a desktop computer in some applications.

The first programmable logic controller (PLC) was created by a group of engineers at General Motors (1968). Hundreds or thousands of relays, cam timers and drum sequencer, and dedicated closing-loop controllers were used to control, sequence and safety interlock logic for automotive manufacture, prior to the PLC. The process of upgrading such equipment for the annual model transition was very long and costly, as professional electricians had to rewire the relay systems. Today PLC technology has evolved, with many other essential functions and language programming capabilities. Today’s PLCs offer faster scanning times, usable input / output space, and special interfaces for directly connecting non-traditional devices to the PLC. They can not only interact with other control systems; they can also carry out investigations and diagnose their own faults and a computer or process malfunction