Incremental encoders are very simple and basic devices which provide pulses or signals to a controller. They DO NOT maintain positional data. Incremental encoders are used to track motion and can be used to determine position and velocity. Pulses are typically provided in an A Quad B format. Details can be found in Output Formats 101(Incremental). This can be either linear or rotary motion. Because the direction can be determined, very accurate measurements can be made.