The term programmable logic controller (PLC) refers to the industrial digital computers that are designed for controlling various manufacturing equipment such as industrial robots, escalators, power stations, and assembly lines. These sophisticated devices are used to control production processes where dependable controls, flexible programming, and ease of troubleshooting is of immense importance.

The significance of industrial computers increases in applications where precision with zero error is critical. Initially, it was the automotive industry that utilized computer-controlled systems in order to replace cam timers and hard-wired relays. Now, computer-driven tools have become a vital part of industrial process control and factory automation.

Unlike personal computers, PLC is capable of performing in harsh industrial environments where temperature, humidity, dust, mechanical shocks and other hazards are prevalent. Manufacturers need a variety of equipment in order to produce a product and make it work for the end users.

All the equipment or devices working on producing something in a facility needs to be organized in terms of time intervals. For instance, in the automobile industry, one device or a set of devices works on painting car exterior and the other machine works on engine parts. One of the functions of an industrial digital computer is to set the specific time frame for machines so that all the processes can be performed in a perfectly harmonious manner.

Industrial computers were introduced in the 1960s and before that, manufacturers relied on cam timers, relays and other similar kinds of devices to streamline their manufacturing processes. They control a wide range of applications from small production systems to large processing plants. Some of the advantages of PLC include:

• Ease of maintenance and installation
• Accuracy and dependability
• Cost-effectiveness
• Low power consumption
• Higher flexibility and integration

Central Processing Unit (CPU), memory, and input & outputs are the three fundamental component of an industrial digital computer. Like in the personal computer, CPU plays the part of a brain in a computer as it performs all the communication, arithmetic, logical and memory related operations. The memory component in PLC operates almost the same way as that of personal computers.

As mentioned earlier, the ability to perform effectively for years in harsh industrial environments is what makes PLCs different from personal computers. A digital computer has to be flexible and configurable. The 21st Century process control expects functional flexibility, superior performance, and a smaller form factor from a control system.

The rapid development in the industrial automation technology has made it possible for manufacturers to produce high-quality products cost-effectively and at large scales. Powerful industrial computers, robots, sensors, intelligent and automated devices are the present and the future of modern industries. It would be hard for industries to stay competitive in future without embracing the modern industrial technologies.