Modbus TCP
OpenEMS Modbus-API (pv)
OpenEMS
Overview
The OpenEMS Modbus-API is a software interface built into the OpenEMS Edge energy management platform, exposing internal channels to external systems over Modbus TCP. The PV variant of this template targets the photovoltaic production component of an OpenEMS installation. It reads two channels from the configured PV component: instantaneous production power at address 327 and cumulative produced energy at address 367. Both are floating-point values updated every cycle. Connecting ModbusCloud Gateway to the OpenEMS Edge TCP port gives installers a live view of solar yield and long-term production totals without modifying the EMS configuration.
Use cases
- Monitor instantaneous PV production power to verify the inverter is operating within expected output levels.
- Track cumulative PV energy over time to calculate monthly and annual solar yield per site.
- Alert on zero production power during daylight hours to detect inverter faults or communication failures.
- Compare daily production totals across multiple OpenEMS sites in the ModbusCloud multi-site overview.
- Verify that the energy counter increases continuously after firmware or configuration changes on the EMS.





