How to suppress interference on the PMS CAN bus of an electrical force measurement switch?

In industrial environments, the PMS CAN bus is susceptible to interference from power supply noise, ground potential differences, and spatial radiation, leading to communication errors and even node damage. Suppression measures need to cover both the physical layer and the data link layer. Physical layer: Connect TVS diodes (such as SMBJ24CA) between the power and ground of the CANH/CANL lines for transient suppression; use a series common-mode inductor CML3225A-101T (100μH) to filter common-mode noise; connect 120Ω terminating resistors at both ends of the bus. Prioritize using isolated CAN transceivers (such as ADM3053), and ensure independent power supplies. On the PCB, place the protective filtering circuit close to the connector. Use shielded twisted-pair cables, with the shield connected to the chassis ground at the PMS end. Data link layer: Properly set the CAN controller baud rate (e.g., 125kbps) and sampling points, and enable error counting and automatic retransmission. Add message verification and timeout retransmission mechanisms to the software. Furthermore, ensure all CAN nodes have a good common ground or are potential isolated. With suppression, the CAN bus can maintain error-free communication under IEC 61000-4-4 EFT level 4 (4kV) interference, meeting the ISO 11898 standard.