Why do power_a through power_d all read zero at night?

The SOFAR G3 inverter powers its communication processor from the PV DC bus. Once PV generation drops to zero after sunset, the internal MCU sleeps and the RS-485 interface stops responding until sunrise. This is normal behaviour; schedule any polling jobs for daylight hours.

The gateway connects but all register values show as invalid. What now?

Check that the Modbus unit ID in the portal matches the address set on the inverter LCD. Also verify baud rate is 9600, 8-N-1. If the inverter firmware is ME_0D_2701_5.08 or earlier, FC-03 frames may be truncated; upgrade the logger firmware to ME_08_2701_2.06 or newer to restore full register reads.

Power values look scaled incorrectly or appear ten times too large. Why?

Registers 1414, 1417, 1420, and 1422 use a scaling factor of 0.01 kW per raw unit in the G3 Modbus protocol. Confirm your integration applies this factor. Also note the G3 protocol transmits 16-bit data in Big Endian order (high byte first), so verify your byte-swap settings match.

RS-485 communication is intermittent across multiple inverters on one bus.

Each inverter on a daisy-chain RS485 bus must have a unique Modbus address set via the LCD, and the final device in the chain requires a 120-ohm termination resistor. If wires were swapped on the RJ45 COM connector (A+ and B- reversed), communication will fail; try swapping the pair. Keep total bus length within cable spec and avoid un-terminated stubs.

Free Modbus template: SofarSolar SOFAR 5…24KTL-G3 (pv)

The SofarSolar SOFAR 5...24KTL-G3 is a three-phase string inverter designed for commercial and residential rooftop photovoltaic installations. This ModbusCloud template connects via Modbus RTU over RS485 and reads per-string DC power across up to four PV inputs (power_a through power_d) plus a 32-bit cumulative energy counter. Supported devices include the SOFAR 5...24KTL-G3, HYD 5...20K-3PH, HYD 3...6K-EP, and SOFAR 80...136KTL. Having per-string and total-yield data in one portal gives installers a fast baseline for performance and fault triage.

Name	Address	Function	Type	Unit	Access
power_a Instantaneous power output of PV string 1, scaled 0.01 kW per unit.	1414	FC03	uint16	kW	R
power_b Instantaneous power output of PV string 2, scaled 0.01 kW per unit.	1417	FC03	uint16	kW	R
power_c Instantaneous power output of PV string 3, scaled 0.01 kW per unit.	1420	FC03	uint16	kW	R
power_d Instantaneous reading for PV channel 4, fourth DC input.	1422	FC03	uint16		R
energy Cumulative total PV energy generation, 32-bit counter.	1670	FC03	uint32		R

SofarSolar SOFAR 5…24KTL-G3 (pv)

Overview

Use cases

Installation

Things to watch for

Registers (5)

Working with Modbus in your projects?

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