Both registers return zero even when the sun is shining. Why?

The H1 inverter only reports PV power on these registers when the inverter is actively running in a grid-tied or hybrid operating mode. If the inverter is in standby or night mode, registers 11002 and 11005 read zero. Wait until the inverter transitions to normal operation and the values will populate.

I get a Modbus exception code 0x82 when polling the device.

Function code 4 reads input registers in the 11xxx range. If you accidentally configure function code 3 (holding registers), the FoxESS H1 returns an exception. Confirm the template uses FC4 for addresses 11002 and 11005. Also check that the slave ID matches the inverter setting, which defaults to 247.

The RS485 connection is established but readings are unstable or time out.

The FoxESS H1 RS485 port is shared with the energy meter or CT clamp. Ensure only one Modbus master is connected at a time. Use a short, shielded twisted-pair cable and connect the cable shield to earth at one end only. Termination resistors (120 ohm) may be needed on long runs above a few metres.

power_a reads a plausible value but power_b is always zero, even on clear days.

A persistent zero on power_b (register 11005) while power_a shows production usually indicates that PV string 2 is not connected or is wired incorrectly to the second MPPT input of the inverter. Confirm both PV string connectors are seated on the MPPT 2 DC input and that string voltage is within the inverter's operating range.

Free Modbus template: FoxESS H1 Series Hybrid Inverter (pv)

The FoxESS H1 Series is a single-phase hybrid inverter covering the H1-3.0-E through H1-6.0-E models, designed for residential solar-plus-storage installations. It features dual MPPT inputs, allowing two independent PV strings to be monitored separately. This Modbus RTU template reads PV string 1 power (power_a) and PV string 2 power (power_b) via RS485, giving installers a direct, cloud-independent view of per-string solar production in the ModbusCloud portal. Tracking both strings individually helps detect shading, degradation, or wiring faults that a single combined reading would mask.

Name	Address	Function	Type	Unit	Access
power_a PV string 1 instantaneous DC power output, in kilowatts.	11002	FC04	int16	kW	R
power_b PV string 2 instantaneous DC power output, in kilowatts.	11005	FC04	int16	kW	R