Solarna Systems Monitoring Modernisation

Engineering design example

Multi-inverter monitoring retrofit

An integration example for existing inverter, meter, and environmental data, covering point mapping, quality states, alarms, validation, and controlled handover.

Integration example ยท Representative architecture, devices, and data-quality rules.

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Architecture

Field data path and system boundaries

The concept separates field acquisition, edge processing, transport, storage, and visualisation so each interface can be reviewed and tested.

Representative data path

Inverters, meter
and weather sensors RS-485 or Ethernet
field segments Edge gateway
and quality logic Approved secure
data transport Historian, alarms
and dashboard

Logical data flow. Site design defines network zones, secure access and data retention.

Inputs required

  • OEM register maps and supported communications interfaces.
  • Existing network drawing, device inventory, and firmware versions.
  • Approved device addresses, baud rates, unit IDs, and polling limits.
  • Metering direction, CT ratios, engineering units, and sign convention.
  • Dashboard users, alarm ownership, retention, and reporting needs.

Engineering outputs

  • Communications architecture and device-address schedule.
  • Normalised point list with scale, units, and quality rules.
  • Dashboard wireframe, alarm matrix, and event definitions.
  • Factory and site acceptance test records.
  • Configuration backup, issue log, and as-built handover index.

Data model

Point definitions and data quality

Monitoring point schedule

Point ID Engineering value Required validation
P_AC_TOTALTotal active power (kW)Register, type, scale, sign, aggregation
E_TOTALLifetime energy (kWh)Rollover, persistence, replacement handling
GRID_V_LL_AVGAverage line voltage (V)Phase source, range, sampling, missing phase
DEVICE_STATENormalised operating stateOEM state table and unknown-code response
ALARM_ACTIVEActive alarm summaryOEM code, severity, timestamp, acknowledgement
Fresh

Valid

The latest sample passes type, range, timestamp, and source-quality checks.

Timed out

Stale

The last value may remain visible, but it is clearly marked and excluded from control decisions.

Rejected

Invalid

Unsupported, out-of-range, or malformed data is not silently presented as a valid measurement.

No usable source

Unavailable

No usable measurement is available from the source. Show the source loss and recovery state; never substitute a valid zero. Any retained sample remains labelled as stale with its timestamp.

Validation

Test evidence from point mapping through operator acceptance

Factory test

  • Verify data types, byte order, scaling, and sign convention.
  • Simulate normal, stale, invalid, and communications-loss states.
  • Check alarm priority, delay, acknowledgement, and recovery.
  • Confirm dashboard units, labels, timestamps, and aggregation.

Site acceptance

  • Compare displayed values with approved local equipment readings.
  • Verify time synchronisation and event sequence across devices.
  • Prove network-loss alarms and the agreed recovery behaviour.
  • Record unresolved deviations with an owner and closeout evidence.

Handover

Handover records for ongoing support

The closeout pack includes the approved point list, architecture, configuration backup, test evidence, open issues, and access ownership.

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