How to eliminate ground loop interference in the PAC intelligent controller?

The ground loop interference of the intelligent controller PAC originates from the potential difference formed by multiple grounding points within the system, causing the common-mode current to generate noise voltage on the signal reference ground. Elimination methods include: using a single-point grounding system to converge all digital, analog, and power grounds at the PAC main grounding point through a 0Ω resistor or ferrite bead; for backplane systems requiring multiple grounding points, using a CMZ3225A-510T common-mode inductor or an ESDLC5V0D3B isolator to break the ground loop at the interface; using shielded twisted-pair cables for I/O communication, with the shield grounded to the PAC side at one end; in PCB design, using isolation islands and bridging common-mode inductors (such as CMZ2012A-900T) to segment the ground plane in sensitive analog areas; actual measurements show that this solution can reduce the ground loop noise voltage of the PAC in the 10kHz-1MHz frequency band from 100mV to below 10mV, meeting the conducted immunity requirements of IEC61000-4-6 Level 2 (3V).