An incremental encoder produces a series of square waves as it rotates. The number of square wave cycles produced per one turn of the shaft is called the encoder resolution. Generally, incremental encoders provide more resolution at a lower cost than their absolute cousins. They also have a simpler interface because they have fewer output lines.
These encoders are ideal for applications where relative movement is desired. They are available as shafted or hollow shaft (blind and through) in package sizes from 1.18" (30mm) to 5.2" (132.08mm)