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.
Pepperl+Fuchs offers rotary encoders with two different ignition protection types. They are distinguished between the ignition protection type “flame proof enclosure” (EEx d) and the ignition protection type “Intrinsic Safety” (EEx i).
Ignition protection type EEx d
Ignition protection type EEx i
In case of the ignition protection type EEx i the voltage and current levels are kept at such a low level that the occurrence of an ignition spark is prevented, thus preventing the ignition of an explosive atmosphere. The following devices are designed in accordance with this ignition protection type: