FoxESS H3-Pro/Smart Series Hybrid Inverter (pv)
The FoxESS H3-Pro/Smart Series is a three-phase hybrid inverter for residential and commercial solar-plus-storage installations. This Modbus RTU template reads per-string PV power across six input strings (power_a through power_f, addresses 39279 to 39289), giving you a live view of each MPPT channel's contribution. With per-string resolution in your ModbusCloud portal, you can detect underperforming strings, shading effects, and soiling losses as they happen rather than waiting for end-of-day yield reports.
- Protocol
- Modbus RTU
- Connection
- RS485
- Registers
- 6, read only
- Brand
- FoxESS
- Last updated
Registers (6)
6 read, 0 write
| Name | Unit | Access | Address (Hidden until you enter your email) | Function (hidden) | Type (hidden) |
|---|---|---|---|---|---|
| power_a | W | Read | |||
| power_b | W | Read | |||
| power_c | W | Read | |||
| power_d | W | Read | |||
| power_e | W | Read | |||
| power_f | W | Read |
Loading registers…
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Use cases
- Monitor each of the six PV string power values in real time to spot sudden drops caused by shading or soiling.
- Compare string outputs across the array to verify that all MPPT channels are producing proportional power under identical irradiance.
- Alert on any single string reading zero watts during daylight hours to detect a blown fuse, disconnection, or faulty module.
- Track per-string power trends over weeks to identify gradual capacity degradation on specific strings before it affects yield.
- Report daily peak power per string to verify installation quality after commissioning or following panel replacement work.
Installation
Enable Modbus communication on the FoxESS H3-Pro/Smart inverter by navigating to the display menu, entering the password (default 0000), and confirming RS485 communication is active under the communication or Modbus section.
Connect a twisted-pair RS485 cable to the EMS 485 A/B pins on the inverter's COM or Meter connector, then wire the other end to the ModbusCloud Gateway RS485 terminals, observing correct A/B polarity.
In the ModbusCloud portal, add the ModbusCloud Gateway, import the FoxESS H3-Pro/Smart Series template, and set the Modbus unit ID to 247 (the factory default for FoxESS inverters).
Verify the connection by spot-checking the power_a register (address 39279) during daylight: a non-zero int32 watt value confirms correct wiring, baud rate, and unit ID.
Things to watch for
All six string power registers return zero even in full sun. Why?
Confirm the RS485 wires are connected to the correct EMS 485 A/B pins on the inverter's COM connector, not to the Meter 485 pins. Also verify the unit ID matches the inverter setting (factory default is 247) and that the baud rate in the Gateway matches the inverter's RS485 configuration.
I get exception code 0x83 or a timeout. What is wrong?
Exception 0x83 (illegal data address) or timeouts on the H3-Pro/Smart often occur when reads span a range that the inverter restricts to individual register reads. Reduce the batch read size in your Gateway settings to 50 registers or fewer per request, as this is a known requirement for the H3-Pro model.
String power values seem correct but are always slightly offset. How do I fix this?
The official FoxESS protocol documents these registers as int32 (two consecutive 16-bit registers). If you see values that are always a fraction of the expected output, verify the data type is set to int32 and not int16. Reading only the high or low word of a 32-bit pair produces a scaled-down or zero result.
The H3-Pro/Smart uses a different register map than the standard H3. Which template do I need?
The H3-Pro and H3-Smart use a distinct register layout that differs from the standard H3 series. Always use this dedicated H3-Pro/Smart template rather than a generic H3 template. Applying the wrong template will result in mismatched addresses and incorrect or absent readings across all six string registers.
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