2. Automation components

2.1 Sensors

The sensor provides the control system with feedback (input) on the system's status. It converts physical information from the power train into electrical (or pneumatic) signals that can be processed by the control system. There are three types of sensors:

• on/off (O/O) sensors, which are the most common types used in sequential and combinational automation. These include mechanical contact sensors, proximity sensors, and distance sensors; they output a 0 or 1 signal, known as an on/off signal. These are referred to as sensors;

• analog devices that convert values such as position, pressure, and temperature into a signal (voltage or current) that varies continuously between two limit values;...