Reads energy data from OpenEMS-based devices via Modbus TCP
Overview
This template reads energy data from OpenEMS-based devices such as the Fenecon Pro Hybrid 10 via Modbus TCP. It provides grid, production, consumption, and ESS (energy storage) metrics per phase and as totals, including state of charge, active power, and cumulative energy values.
Key readings
ESS State of Charge
Grid Active Power L1 to L3
Production Active Power L1 to L3
Consumption Active Power L1 to L3
ESS Active/Discharge Power
Grid Buy/Sell Active Energy
Use cases
Monitor grid import and export power per phase on a live dashboard for your customer.
Track ESS state of charge over time to evaluate battery cycling behaviour and capacity usage.
Create an alert when grid active power exceeds a contractual demand limit for more than five minutes.
Compare production active power against consumption to assess self-consumption ratios on a daily basis.
Log cumulative grid buy and sell energy values for monthly energy reporting to end customers.
Use virtual input mappings to feed energy manager logic with real-time grid, production, and storage data.
Installation
1Connect the ModbusCloud gateway (MCG or MLP series) to the same local network as the OpenEMS device and ensure Modbus TCP is enabled on the device.
2Verify the IP address of the OpenEMS device and confirm the default Modbus TCP port (typically 502) is accessible from the gateway.
3Import the Fenecon OpenEMS template in the ModbusCloud platform and assign the correct IP address and unit ID to the connection.
4Confirm that register data appears in the ModbusCloud dashboard by checking a known value such as ESS State of Charge against the local device display.
5If using energy manager virtual inputs, map sum_GridActivePower to Gpwr, sum_ProductionActivePower to Ppwr, sum_EssDischargePower to Spwr, and sum_EssSoc to Soc.
Things to watch for
01
Which data types are used in the registers?
Power registers use float32 and energy registers use float64. The template has these types preconfigured, so no manual adjustment is required.
02
Can I use this template with OpenEMS devices other than the Fenecon Pro Hybrid 10?
Yes. The template is based on the standard OpenEMS Modbus API. Any device running OpenEMS with Modbus TCP enabled should expose the same register map.
03
Why do some power values show negative numbers?
Negative values typically indicate direction. For example, a negative grid active power value usually means the site is exporting energy to the grid rather than importing.
04
What Modbus TCP port and unit ID should I configure?
The default Modbus TCP port is usually 502. The unit ID depends on the OpenEMS configuration. Check the device settings or OpenEMS admin interface to confirm both values.
Registers (39)
39 read / 0 write
Name
Address
Function
Type
Unit
Access
sum_State
222
FC03
uint16
R
sum_EssSoc
Energiemanager - Soc
302
FC03
uint16
%
R
sum_EssActivePower
303
FC03
float32
kW
R
sum_GridActivePower
Energiemanager - Gpwr
315
FC03
float32
kW
R
sum_GridMinActivePower
317
FC03
float32
kW
R
sum_GridMaxActivePower
319
FC03
float32
kW
R
sum_GridActivePowerL1
Netz L1
397
FC03
float32
kW
R
sum_GridActivePowerL2
Netz L2
399
FC03
float32
kW
R
sum_GridActivePowerL3
Netz L3
401
FC03
float32
kW
R
sum_ProductionActivePower
Energiemanager - Ppwr
327
FC03
float32
kW
R
sum_ProductionMaxActivePower
329
FC03
float32
kW
R
sum_ProductionAcActivePower
331
FC03
float32
kW
R
sum_ProductionMaxAcActivePower
333
FC03
float32
kW
R
sum_ProductionDcActualPower
339
FC03
float32
kW
R
sum_ProductionMaxDcActualPower
341
FC03
float32
kW
R
sum_ConsumptionActivePower
343
FC03
float32
kW
R
sum_ConsumptionMaxActivePower
345
FC03
float32
kW
R
sum_EssActivePowerL1
391
FC03
float32
kW
R
sum_EssActivePowerL2
393
FC03
float32
kW
R
sum_EssActivePowerL3
395
FC03
float32
kW
R
sum_ProductionAcActivePowerL1
403
FC03
float32
kW
R
sum_ProductionAcActivePowerL2
405
FC03
float32
kW
R
sum_ProductionAcActivePowerL3
407
FC03
float32
kW
R
sum_ConsumptionActivePowerL1
409
FC03
float32
kW
R
sum_ConsumptionActivePowerL2
411
FC03
float32
kW
R
sum_ConsumptionActivePowerL3
413
FC03
float32
kW
R
sum_EssActiveChargeEnergy
351
FC03
float64
kWh
R
sum_EssActiveDischargeEnergy
355
FC03
float64
kWh
R
sum_GridBuyActiveEnergy
Netzbezug
359
FC03
float64
kWh
R
sum_GridSellActiveEnergy
Netzeinspeisung
363
FC03
float64
kWh
R
sum_ProductionActiveEnergy
367
FC03
float64
kWh
R
sum_ProductionAcActiveEnergy
371
FC03
float64
kWh
R
sum_ProductionDcActiveEnergy
375
FC03
float64
kWh
R
sum_ConsumptionActiveEnergy
379
FC03
float64
kWh
R
sum_EssDcChargeEnergy
383
FC03
float64
kWh
R
sum_EssDcDischargeEnergy
387
FC03
float64
kWh
R
sum_GridMode
Grid-Mode
417
FC03
uint16
R
sum_EssReactivePower
309
FC03
float32
kW
R
sum_EssDischargePower
Energiemanager - Spwr
415
FC03
float32
kW
R
Working with Modbus in your projects?
ModbusCloud is the hardware-plus-software platform that installers use to monitor, visualise and control Modbus devices from one portal. This template is one of hundreds you can use right away.
