How should the shielding ground of the PAC bus in an intelligent controller be handled?

Proper shielding and grounding of the PAC bus (such as Ethernet, CAN, USB) of intelligent controllers is crucial for suppressing radiation and immunity. The shielding layer of the shielded cable should loop 360 degrees to the metal connector housing at the connector, and the housing should then overlap with the chassis through a low-impedance path (such as conductive foam or metal springs), with an overlap resistance of less than 10mΩ. For shielded connectors on the PCB, their metal housings should be connected to the PCB's shielding ground plane through multiple pads. This ground plane should be independent of the signal ground and connected to the chassis through screws. If the bus needs to pass through a compartment, a shielded compartment through-board connector should be used. At the same time, avoid forming a "pigtail" grounding with the shielding layer. Tests show that proper shielding and grounding can reduce bus radiated emissions by 15dB and improve immunity by 20dB, and pass the IEC61000-4-3 radiated immunity test and the IEC61000-4-6 conducted immunity test.