How does a poor grounding of the motion controller MC cause a malfunction?

Poor grounding in the motion controller (MC) can cause malfunctions through various mechanisms. High-impedance grounding prevents common-mode noise from dissipating, causing significant fluctuations on the signal ground that may exceed the chip's common-mode input range, resulting in digital errors or analog distortion. Ground loops can induce power frequency or radio frequency interference, generating noise current in the signal loop. Ground potential differences can lead to inconsistent reference levels between remote devices, causing communication errors or measurement deviations. Transient currents flowing through poor grounding paths create voltage drops, affecting sensitive circuits through coupling.

Reduced shielding effectiveness makes the module susceptible to radiated interference. Common fault symptoms include: encoder counting fluctuations, intermittent communication interruptions, analog measurement drift, and unexplained CPU resets. Solutions include checking all grounding connections for tightness and low resistance; optimizing the grounding architecture; adding common-mode chokes or isolators to sensitive interfaces; and using differential transmission for long lines. Measuring ground noise voltage and current can pinpoint the location of the grounding malfunction.