Industrial automation could not exist without PLC controllers. They constitute the heart of the entire system in automated technological processes. What exactly are they, where are they used and why are they crucial for the industry?
What are PLC controllers?
The abbreviation PLC comes from Programmable Logic Controller. This device is based on a microprocessor system that allows you to control the operation of another device - e.g. a machine located on the production line or the line itself.
PLC controllers were introduced to replace contactor-relay systems. This eliminated complicated wiring. In the case of PLC, actions such as turning devices on and off or setting parameters are performed inside the controller.
Principle of operation of the PLC controller
The PLC executes a program containing a looped sequence of commands. This means that it works in a closed software loop. The program includes instructions and variables such as the command to write and read data, perform arithmetic or logical operations. The program itself is created on a computer and then transformed in such a way that it can be read by a microprocessor system.
The basic principle of operation of the controller consists of 6 steps:
- Initialization and checking operation.
- Reading the input signals.
- Program execution.
- Recording of output signals.
- Communication with other devices (optional).
- Self-diagnosis with interruption of work if an error is detected.
What is the role of PLC controllers in industry?
The popularity of PLC controllers in industry is primarily due to their high reliability and universality of applications. High efficiency makes them suitable even in demanding applications. Another great advantage of PLC controllers is the ability to make modifications to the program without changing the hardware.
In times of rising energy prices and increasing interest in pro-ecological and pro-economic solutions, PLC controllers beat alternatives also thanks to low energy consumption and significantly less material needed (e.g. cabling, contactors).
PLC controllers and system migration
Migration of a system based on PLC controllers is most often due to technological reasons. Older components that no longer have manufacturer support should be replaced regularly. Failure to update poses a threat to the security and functionality of the system.
The production processes themselves also require increasingly far-reaching automation, robotization and digitization. New PLC controllers demonstrate increasingly better scalability and adaptability, and also provide a wider range of integration with various technologies.