All register readings show zero or timeout errors. What is wrong?

Check that the baud rate on the inverter matches 9600/8/N/1 and that the unit ID in the portal matches the slave address set on the inverter's LCD. Also verify A+ and B- wiring polarity at both ends. Swapping the two RS485 wires fixes a large proportion of communication failures on SofarSolar HYD installations.

The 'power' register reads unexpected large positive values at night.

The HYD 5...20K-3PH protocol uses big-endian byte order. If your reading tool or gateway is interpreting bytes in little-endian order the int16 value will appear corrupted. Confirm the ModbusCloud Gateway is set to big-endian for this device. A value near 65535 usually indicates a byte-swap issue on a negative signed integer.

Per-phase power values look inconsistent with the total power register.

The SofarSolar HYD G3 protocol assigns phase registers at non-contiguous addresses (1171, 1182, 1193). Some polling tools batch-read a contiguous block and return zeroes for gaps. ModbusCloud polls each register address individually, so values should match. If they do not, confirm the firmware on the inverter supports the extended G3 register map.

The cumulative energy counter seems to reset or jump unexpectedly.

Register 1678 is a 32-bit unsigned value. If you read only one 16-bit word you will see only the high or low half, producing incorrect totals. Ensure the template type is set to uint32 (two consecutive registers). The counter also does not roll back after a firmware update, but a factory reset will clear it.

Free Modbus template: SofarSolar HYD 5…20K-3PH (grid)

The SofarSolar HYD 5...20K-3PH is a three-phase hybrid inverter covering 5 to 20 kW, designed for residential and light-commercial PV systems with battery storage. This Modbus RTU template reads the grid-side register set: total active power, per-phase currents and signed active power for phases A, B, and C, and a cumulative energy counter. Sign convention on the power registers follows the SofarSolar HYD protocol, where negative values indicate export to the grid. Importing this template into ModbusCloud gives installers real-time and historical grid-side visibility across all supported HYD variants without manual register entry.

Name	Address	Function	Type	Unit	Access
power Total active grid power, signed; negative means export to grid.	1160	FC03	int16	W	R
currents_a AC current on phase A, unsigned integer.	1170	FC03	uint16	A	R
currents_b AC current on phase B, unsigned integer.	1181	FC03	uint16	A	R
currents_c AC current on phase C, unsigned integer.	1192	FC03	uint16	A	R
powers_a Active power on phase A, signed; negative means export.	1171	FC03	int16	W	R
powers_b Active power on phase B, signed; negative means export.	1182	FC03	int16	W	R
powers_c Active power on phase C, signed; negative means export.	1193	FC03	int16	W	R
energy Cumulative grid energy, 32-bit unsigned counter.	1678	FC03	uint32	Wh	R

SofarSolar HYD 5…20K-3PH (grid)

Overview

Use cases

Installation

Things to watch for

Registers (8)

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