Skip to content
Articles·Automation Technician·Materials and tools

Components and equipment in automation

Sensors PLCs motor control and the pneumatic and hydraulic

An automatic system is made up of components each with a task. To understand and troubleshoot a system you must know the parts and their role. Roughly speaking a system has a sensing side (sensors) a thinking side (control) and an acting side (actuators) — plus the energy and signals that bind them together.

§Sensors and sensors — the system's senses

  • 01End stops and proximity sensors that sense a position or a part
  • 02Pressure, level and flow sensors in process plants
  • 03Temperature sensor for heating and cooling
  • 04Speed and position sensors on motors and shafts

§The steering — the system's brain

The programmable control (PLC) is the central element in most systems. It reads input signals from sensors, runs its program and sends output signals to motors, valves and lights. For larger and more complex systems, operating panels and higher-level systems are often connected, which monitor and control multiple PLCs at once.

§Actuators — the system's muscles

The actuators perform the action. These can be electric motors that drive belts, pumps and machines, valves that open and close for liquids or air, or cylinders that push and pull. The frequency converter lets a motor run at variable speed, so the system can adapt instead of just being on or off.

FunctionComponentsRole
SenseSensors feelers end switchesMeasurement results
ThinkingPLC: collects control of large systems and enables remote monitoring.Makes decisions based on programme and signals
TradeMotors, valves, cylindersExecutes the movement or regulation.
DriveFrequency converter, motor controlControls speed and force

§Pneumatics and hydraulics

Many systems use compressed air (pneumatics) or pressure fluid (hydraulics) to create movement. Pneumatics is fast and clean and is used for light, quick movements; hydraulics can create very large forces and is used where heavy lifting or pressing is needed. The automation technician must understand both — valves, cylinders, pressure and safety — because they are found in countless machines.

§Tools and measuring equipment

Daily practice includes hand tools, crimping and stripping tools for cables, and above all measuring equipment. The multimeter is the technician's most important tool for troubleshooting — it measures voltage, current and continuity and reveals where in the circuit a signal disappears. The portable with programming software is equally essential when the PLC needs to be read or corrected.