How to rectify feedback distortion in the MC encoder of a motion controller?

To correct distortion in the MC encoder feedback signal of the motion controller, it is necessary to locate the cause of the distortion and address it accordingly. If the waveform exhibits overshoot or ringing, it is usually caused by impedance mismatch, requiring the addition of matching resistors at the encoder output or controller input. If there are high-frequency spikes in the signal, it may be due to power supply noise or spatial coupling interference, requiring enhanced encoder power supply filtering and the addition of RC low-pass filters or ferrite beads to the signal lines. If common-mode offset occurs in the differential signal, check the grounding of the cable shield and add a common-mode choke. If the distortion is severe during motor start-up and shutdown, it may be caused by ground noise, requiring optimization of the grounding between the encoder and controller, or the use of an isolated interface. Use an oscilloscope to observe the distorted waveform and a spectrum analyzer to analyze the noise components. Corrective measures may include: adjusting the termination resistor value, replacing with a higher-quality shielded cable, adding filtering components, and improving grounding connections. After rectification, long-term testing under real-world conditions is necessary to ensure stable and accurate feedback.