How does the power measurement switch (PMS) coordinate with the upper-level system's EMC (Electronic Control System) communication?

When a PMS (Power Management System) communicates with an upper-level monitoring system (such as SCADA or PLC) as a subsystem, collaborative EMC design at the system level is necessary to avoid the interface becoming a point of entry for interference due to independent design. Key points of collaboration include: a unified grounding strategy, agreeing on the reference ground potential of the communication interface, typically using the PMS's chassis ground (PE) as a common reference point; consistent interface standards, such as using isolated RS485 or Ethernet, and agreeing on protection levels (e.g., 4kV surge voltage); standardized cable specifications, specifying the use of shielded twisted-pair cables, with the shield connected to chassis ground at both ends (or one end); on the PMS side, the interface circuit should be designed with protection and filtering according to the aforementioned RS485/CAN specifications. On the upper-level system side, corresponding protection measures should also be in place to avoid voltage differentials caused by unilateral protection. Both parties can agree to add redundancy checks and retransmission mechanisms to the communication protocol to improve fault tolerance. During system installation, ensure good equipotential bonding between the PMS and the upper-level equipment. Through collaborative design, the entire communication link can be treated as a whole to resist interference, avoiding communication failures caused by the PMS meeting standards alone but the upper-level system being incompatible.