Component glossary for beginners
The building blocks you encounter again and again on an automated system
At first, a system can look like a tangle of boxes, cables and hoses. But most systems are built from the same basic types of components that work together. When you know them, the pattern starts to make sense.
§The steering — the system's brain
The PLC is the system's brain but the logic must be written in a language the controller understands. The article reviews the international standard IEC 61131-3 its programming languages and when to choose which — and why standardization and good documentation are crucial when a system must last many years.
§Sensors – the system's senses
- 01Sensors that detect if something is present (e.g. an item on a conveyor).
- 02Scale ratio
- 03End stops and contacts that report whether something has reached its position.
§Actuators – things that move
Actuators are what perform the action: motors that rotate, cylinders that push, valves that open and close. They receive commands from the control and convert the signal into movement.
§Pressure and movement: pneumatics and hydraulics
Pneumatics uses compressed air for fast, light movements; hydraulics uses pressurized oil for slow, powerful movements. Both systems store energy, even when the power is off – something you must always remember when working on the system.
§Connections between
Cables, terminal blocks, fuses and relays tie it all together and protect components. Labeling and diagrams are your way to find your way around – without them you're groping in the dark.