Encoders are generally used on the shaft end of ordinary motors to collect the rotation angle. Servo and stepper motors usually do not need to be equipped with encoders because they have built-in signal feedback. The number of pulse signals is output by measuring how many dark lines the rotor sweeps through inside the encoder. The accuracy selection is determined by the encoder's resolution; the higher the resolution, the more accurate the angle recording. Some encoders have AB output, while others have A+B+AB- output. These two signal lines are connected to the high-speed counter input terminal of the PLC input, usually one of the first few points of the PLC input. Program control also requires consulting the manual to receive signals using a high-speed counter, calculate the desired number of motor rotations, and then control the motor's start and stop to achieve precise positioning of the motor in linear or rotary angle.
The resolution of a servo motor encoder is adjustable and can be changed as the signal is subdivided. The higher the subdivision factor, the smaller the resolution, but the higher the subdivision factor, the greater the error introduced.
A servo motor encoder is a sensor installed on a servo motor to measure the position of the magnetic poles and the rotation angle and speed of the servo motor. Based on the different physical media, servo motor encoders can be divided into photoelectric encoders and magnetoelectric encoders. In addition, a rotary transformer is also considered a special type of servo encoder. The market mainly uses photoelectric encoders, but magnetoelectric encoders, as a rising star, have the characteristics of reliability, low price, and resistance to pollution, and are trending towards surpassing photoelectric encoders.
