ARServerHMI/SCADA
ENID

HMI / SCADA use case

Expose selected IEC 61850 relay data as stable Modbus TCP points.

This use case is for teams whose HMI, SCADA, or DCS environment understands Modbus TCP better than IEC 61850 MMS.

Integration route

Relay / IED → ARServer → Modbus TCP → HMI/SCADA

ARServer reads selected IEC 61850 values from the relay, keeps a runtime cache, and exposes mapped points through a Modbus TCP server. The HMI or SCADA system polls ARServer instead of speaking IEC 61850 directly.

Best signals to start with

  • Breaker or switch position.
  • Protection start, trip, and operation indications.
  • Major alarms and equipment status.
  • Measurements that have clear scaling and engineering units.

What must be documented

Every Modbus point needs address, data type, scale, Boolean meaning, source IEC object, quality behavior, stale behavior, and expected HMI interpretation.

Do not hand over a register number only. A Modbus map without source object, quality handling, and stale behavior is not an engineering deliverable.

Acceptance checklist

  1. IED communication is stable on the test network.
  2. Selected IEC objects read correctly.
  3. Modbus client can poll every mapped point.
  4. HMI displays the correct meaning and scaling.
  5. Communication loss produces a visible stale or diagnostic state.
Learn the bridge conceptUnderstand how IEC 61850 object names become Modbus registers.Build the first routeFollow the zero-to-running workflow before adding many points.