Modbus TCP is not responding on the Kostal inverter. What should I check?

Ensure Modbus TCP is explicitly enabled in the inverter configuration menu. Some Kostal models have it disabled by default. Also verify the inverter and the gateway are on the same subnet and that port 502 is not blocked by a firewall.

Battery charge and discharge power values look incorrect or out of range.

Battery charge and discharge power registers use int16 format, while most other registers use float32. Confirm your gateway is configured to read these specific registers as int16. A mismatch in data type will produce incorrect values.

Yield values show zero even though the system is producing energy.

Check that the register addresses match your Kostal inverter model and firmware version. Refer to the official Kostal Modbus register map for your specific model. Some older firmware versions may not expose all registers.

Can I write setpoints or control the inverter with this template?

No. This template is read-only and does not include any write registers. It is designed for monitoring solar yield, consumption, and battery data only.

Free Modbus template: Kostal Modbus-TCP and Battery

Name: Kostal Modbus-TCP and Battery
Brand: Kostal
SKU: 6a2202df-e69d-49bb-ae97-baa3c472871a

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Free Modbus template: Kostal Modbus-TCP and Battery | ModbusCloud

Registers (12)

12 read / 0 write

Name	Address	Function	Type	Unit	Access
Yield Total (Ep)	320	FC03	float32	kWh	R
Total AC Active Power (Pp)	172	FC03	float32	kW	R
Total Home Consumption Battery	110	FC03	float32	kWh	R
Total Home Consumption Grid (Ev)	112	FC03	float32	kWh	R
Total Home Consumption PV	114	FC03	float32	kWh	R
Total Home Consumption	118	FC03	float32	kWh	R
Total active Power (Pv), (Powermeter)	252	FC03	float32	kW	R
Actual State of Charge (Ss)	210	FC03	float32	%	R
Actual battery charge_discharge power (Ps)	582	FC03	int16	kW	R
Yield Yearly	324	FC03	float32	kWh	R
Yield Daily	322	FC03	float32	kWh	R
Yield Monthly	326	FC03	float32	kWh	R