The rotary encoder is an opto-mechanical methods such as axis angle is converted to a digital signal output of sophisticated sensors, divided into incremental rotary encoders and absolute rotary encoders, today we talk about incremental rotary encoder It uses.
　　Incremental rotary encoder is the direct use of photoelectric conversion principle square wave pulse output three groups A, B and Z phase; A, B two pulse phase difference of 90 degrees, and thus can easily determine the direction of rotation, and Z for each phase a transfer pulse for homing. The advantage is that the principle of simple structure, mechanical average life of more than tens of thousands of hours, anti-interference ability, high reliability, suitable for long distance transmission, the drawback is absolute position information can not be output shaft rotation.
　　First, the incremental rotary encoder has a resolution of differences, the number of pulses per revolution generated by using the measured number from 6-5400 higher, the number of pulses or more, the higher the resolution; this is an important basis for selection one.
　　Second, the incremental rotary encoders usually have three-way signal outputs (differential six signals): A, B and Z, the general use of TTL level, A pulse front, B pulse after, A, B pulse difference of 90 degrees, issue a Z pulse per revolution, as a reference mechanical zero. A general use leads B or B leads A to be sentenced, I incremental rotary encoder is defined as the encoder shaft clockwise to look forward, ahead of A and B is 90 °, counterclockwise rotation and vice versa for the reverse B A lead of 90 °. There are not the same, depending on the product description.
　　Third, the use of PLC data collection, the choice of high-speed counting module; use the IPC data acquisition, high-speed counting cards can be used; the use of SCM data acquisition, we recommend the use of optical input port coupler.
  　　Fourth, the proposed B pulses do forward (forward) pulse, A pulse to do the reverse (backward) pulse, Z datum zero pulse.
　　Fifth, the establishment of a stack count in the electronic device.