Should the external shielding wire of the edge box be grounded at one end or both ends?

The grounding strategy for the external shielded cable of the edge computing box depends on the interference frequency. For low-frequency magnetic field interference, single-end grounding is recommended to prevent ground loops. For power frequency and radio frequency interference, double-end grounding is recommended to achieve high-frequency shielding. For common EMC issues of edge boxes, if there is a ground potential difference on site and the signal is low-frequency analog (e.g., 4-20mA), single-end grounding is recommended. If it is high-frequency digital communication (e.g., USB Ethernet), double-end 360° grounding is recommended. If necessary, a 1nF 2kV Y capacitor should be connected in series at one end to achieve high-frequency grounding and DC isolation. It is recommended to add a ferrite core (CMZ7060A-701T) with an impedance of 700Ω at the end of the shielding layer to suppress high-frequency resonance at 100MHz. Example: The edge box RS485 shielded cable uses double-end grounding and is connected to the PE via a Y capacitor. The communication rate is 115200bps with no packet loss and passes the IEC61000-4-6 10V test.