Datalogic optical encoders are used for conveyor belt motion control and linear measurement. Incremental encoders produce sinusoidal or square wave outputs, which give an incremental number of pulses per revolution of the shaft. The resolution is defined as Pulse Per Revolution (PPR).Absolute encoders generate a multi-bit digital data information, providing the actual angular position of the shaft. Single-turn absolute encoders repeat the code for every shaft revolution. Multi-turn absolute encoders increase the code at each shaft revolution. Shaft position is retained when the absolute encoder is switched-off, so it can provide the absolute position, as well as rotation speed or direction. Datasensor incremental encoders give a number of pulses per revolution, wheres absolute singleturn or multiturn encoders give a different digital code for each position.