Incremental rotary encoders supply a certain number of pulses for each shaft revolution. Speed is measured by counting the pulses for a period of time. To calculate angle or the distance covered, pulses are counted starting from a reference point.
Dual channel quadrature output encoders feature two signal outputs that are 900 out of phase with each other. This permits the controller to determine direction of rotation and perform bi-directional positioning tasks.
In addition, three-channel incremental encoders have a third signal channel (known as “zero”, or reference, signal) that provides a single pulse for each revolution.
