Encoders are used to translate rotary or linear motion into a digital signal. Usually this is for the purpose of monitoring or controlling motion parameters such as speed, rate, direction, distance, or position.
Some common encoder technologies are mechanical, magnetic, resistive, and optical. Encoders may produce either incremental or absolute signals. Incremental signals provide a series of high and low waves which indicate movement from one position to the next.
Absolute encoders, on the other hand, use a unique “word” for each position, meaning that an absolute encoder provides both the indication that the position has changed and an indication of the absolute position of the encoder.
Visit the British Encoder website to view a wide range of encoders: www.encoder.co.uk