SAJ H2 Series Hybrid Solar Inverter (grid)

Installation

1. 1Enable Modbus TCP on the SAJ H2 Series inverter by inserting the eSolar AIO3 Wi-Fi/Ethernet dongle and confirming it is connected to your local network; note the fixed IP address assigned to the dongle.
2. 2Connect the ModbusCloud Gateway to the same LAN as the inverter dongle, ensuring both devices can reach each other on TCP port 502.
3. 3In the ModbusCloud portal, add a new device, import the SAJ H2 Series Hybrid Solar Inverter (grid) template, and set the unit ID to 1 (the SAJ default slave address) unless you have changed it on the inverter.
4. 4Trigger a manual poll in the portal and spot-check the power register (address 16557) against the inverter's own display or the eSolar app to confirm values align.

Things to watch for

01

The power register reads zero even when the inverter is running. Why?

The SAJ H2 communicates via the eSolar AIO3 dongle. If the dongle has lost its Wi-Fi or Ethernet link, the Modbus TCP socket will accept connections but return zero or stale values. Check the dongle's LED status and confirm it holds a stable IP address before re-polling.

02

Phase current registers A, B, and C all return identical values. Is that normal?

Identical phase currents are only expected on a perfectly balanced three-phase load. If you see the same non-zero value on all three registers, verify that the Modbus TCP client is reading the correct register addresses (16434, 16441, 16448) and that the inverter firmware supports the three-phase current registers for your specific H2 variant.

03

The cumulative energy register wraps around unexpectedly. What is happening?

The energy register is a uint32, so it rolls over at 4,294,967,295 watt-hours (roughly 4.3 GWh). For most residential sites this will not occur for many years, but if the register appears to reset, check whether the inverter firmware has been updated and reset the energy counter, or whether a gateway reconnection caused the type to be read as 16-bit instead of 32-bit.

04

The gateway connects but values are wildly out of range. What should I check?

The SAJ H2 protocol stores several measurements as signed int16 values with an implicit scaling factor applied by the inverter firmware. If your portal displays raw register counts, confirm the template's data type for each register (int16 for power and currents, uint32 for energy) is applied correctly. A missing scale factor or incorrect type will produce values that appear many times too large or too small.

More SAJ templates

SAJ H1 Series Hybrid Solar Inverter (grid)

SAJ

Modbus TCP

2 registers

SAJ H1 Series Hybrid Solar Inverter (pv)

SAJ

Modbus TCP

2 registers

SAJ H2 Series Hybrid Solar Inverter (battery)

SAJ

Modbus TCP

9 registers

SAJ H2 Series Hybrid Solar Inverter (pv)

SAJ

Modbus TCP

2 registers

SAJ H1 Series Hybrid Solar Inverter (battery)

SAJ

Modbus TCP

8 registers

SAJ Inverter R5_V1

SAJ

Modbus RTU

Monitors a single-phase SAJ solar inverter via Modbus RTU

47 registers49

More TCP templates

Algodue Energy meter UEM80-2D E

Algodue Elettronica S.r.l.

Modbus TCP

Measures single-phase energy consumption and production via Modbus TCP.

12 registers46

Sigenergy SigenStore EC (grid)

Sigenergy

Modbus TCP

5 registers1

Fronius GEN24

Fronius

Modbus TCP

Monitors and controls Fronius GEN24 inverters and PV batteries via SunSpec Modbus TCP

0 registers762

HUAWEI SUN2000 Inverter & LUNA2000 battery

Huawei

Modbus TCP

Monitors HUAWEI SUN2000 inverter, LUNA2000 battery, and Smart Power Sensor via Modbus TCP.

4 registers1248

NIBE Nibe S-Series (SG Ready)

NIBE

Modbus TCP

5 registers1

Fronius - Modbus TCP

Fronius

Modbus TCP

Monitors Fronius Symo and Primo inverters via Modbus TCP

15 registers597