Incremental encoders supply a certain number of pulses for each shaft revolution. The measurement of the cycle duration or the counting of the pulses per unit of time supplies the speed of the moment. If the pulses after a reference point are added, the calculated value represents a parameter for the scanned angle or the distance covered.
Two-channel professional encoders - with a phase shift of 90 deg. - enable the follow-up electronic equipment to recognise the direction of rotation of the shaft and thus permit bidirectional positioning tasks.
In addition, three-channel incremental encoders provide a so-called zero signal for each revolution.
