As industry leaders in automation, we enjoy teaching our clients about the machines and components we create and maintain. Here’s what you need to know about the PLC – a key element in the automated manufacturing process:
- PLC stands for Programmable Logic Controller – a special computer device used for industrial control systems.
- It is essentially an industrial computer, built to withstand harsh conditions.
- Used to control devices, the PLC ‘softwires’ components together by monitoring a series of different inputs and manipulating the output for the desired control/effect.
- It contains a programmable (changeable) memory in which a sequence of instructions is stored. Those instructions enable the PLC to perform various useful control functions like relay logic, counting, timing, sequencing, and arithmetic computation.
- Its key advantage is that it is highly flexible in how it can be programmed while still being reliable – meaning no program crashes or mechanical failures (as is the case with some traditional control systems).
- PLCs come in many shapes and sizes. They can be small enough to fit in your shirt pocket while more involved controls systems require large PLC racks.
- Modern day PLCs are programmed with specialised software. A common form of programming is Ladder Logic and involves the use of symbols rather than words.
- A single PLC can be programmed to replace thousands of relays and timers with one programme.
- It can be designed to run its one program at a very fast speed, responding very quickly to any of the events under its control. For example, controlling a machine’s production running at 30 000 units an hour!
- You will find PLCs across a wide range of industries, including manufacturing, travel, aerospace, printing, textiles, agriculture, and film. Where there’s automation, there’s bound to be a PLC (or quite a few) at work!