How to rectify EMC issues related to packet loss during data upload from intelligent low-voltage monitoring units?

Data upload packet loss EMC rectification: The source of interference was located and protection was enhanced.

First, the source was located: the communication line waveform was monitored using an oscilloscope.

Rectification measures: For conducted interference, a common-mode inductor CMZ3225A-510T and a TVS diode SMBJ6.5CA were added; for radiated interference, shielding was strengthened.

Software measures: A retransmission mechanism and CRC check were added.

PCB rectification: Grounding continuity was checked, and power supply decoupling was strengthened.

Through these rectifications, the packet loss rate was reduced from 1% to 0.01%.