Linear sensors are available in many different models and operating techniques. The measurement can be absolute or incremental: with an absolute sensor the reading is available straight away after turning the sensor on, whereas with incremental sensor you need to first go to the home base and start the measuring again from there.
There are both contact and contactless sensors with several different measuring techniques, such as potentiometer, inductive and magnetic contactless.
Output signal is analog potentiometer / 0,5-4,5 / 0-10 VDC or 4 – 20 mA, or digital CANopen.