Sofar KTLX-G3
Three-phase PV inverter that reports solar yield, grid power and faults, with a settable feed-in limit.
The Sofar KTLX-G3 is a three-phase string inverter that converts solar power from two MPPT inputs into grid power for homes and small commercial buildings. This Modbus RTU template reads PV, grid and energy values, operating state, fault codes and temperatures, and lets you set the feed-in limit and switch the inverter on or off from ModbusCloud.
- Protocol
- Modbus RTU
- Connection
- RS485, 9600 baud
- Registers
- 106, read and write
- Brand
- Sofar
- Key readings
- PV power · PV voltage and current · Grid power · Phase voltage · Daily yield · Total yield · Imported and exported energy · Fault codes
- Available commands
- Feed-in limit · Remote on/off
- Compatible models
- KTLX-G3 · Sofar 4.4KTLX-G3
- Last updated
Registers (106)
99 read, 11 write
| Name | Unit | Access | Address (Hidden until you enter your email) | Function (hidden) | Type (hidden) |
|---|---|---|---|---|---|
| PV Voltage 1 | V | Read | |||
| PV Current 1 | A | Read | |||
| PV Power 1 | kW | Read | |||
| PV Voltage 2 | V | Read | |||
| PV Current 2 | A | Read | |||
| PV Power 2 | kW | Read | |||
| PV Power Total | kW | Read | |||
| Grid Frequency | Hz | Read | |||
| Active Power Output Total | kW | Read | |||
| Reactive Power Output Total | var | Read | |||
| Apparent Power Output Total | VA | Read | |||
| Active Power PCC Total | kW | Read | |||
| Reactive Power PCC Total | var | Read | |||
| Apparent Power PCC Total | VA | Read | |||
| Voltage L1 | V | Read | |||
| Current Output L1 | A | Read | |||
| Active Power Output L1 | kW | Read | |||
| Reactive Power Output L1 | var | Read | |||
| Power Factor Output L1 | Read | ||||
| Current PCC L1 | A | Read | |||
| Active Power PCC L1 | kW | Read | |||
| Reactive Power PCC L1 | var | Read | |||
| Power Factor PCC L1 | Read | ||||
| Voltage L2 | V | Read | |||
| Current Output L2 | A | Read | |||
| Active Power Output L2 | kW | Read | |||
| Reactive Power Output L2 | var | Read | |||
| Power Factor Output L2 | Read | ||||
| Current PCC L2 | A | Read | |||
| Active Power PCC L2 | kW | Read | |||
| Reactive Power PCC L2 | var | Read | |||
| Power Factor PCC L2 | Read | ||||
| Voltage L3 | V | Read | |||
| Current Output L3 | A | Read | |||
| Active Power Output L3 | kW | Read | |||
| Reactive Power Output L3 | var | Read | |||
| Power Factor Output L3 | Read | ||||
| Current PCC L3 | A | Read | |||
| Active Power PCC L3 | kW | Read | |||
| Reactive Power PCC L3 | var | Read | |||
| Power Factor PCC L3 | Read | ||||
| Active Power PV Ext | kW | Read | |||
| Active Power Load Sys | kW | Read | |||
| Voltage Phase L1N | V | Read | |||
| Current Output L1N | A | Read | |||
| Active Power Output L1N | kW | Read | |||
| Current PCC L1N | A | Read | |||
| Active Power PCC L1N | kW | Read | |||
| Voltage Phase L2N | V | Read | |||
| Current Output L2N | A | Read | |||
| Active Power Output L2N | kW | Read | |||
| Current PCC L2N | A | Read | |||
| Active Power PCC L2N | kW | Read | |||
| Voltage Line L1 | V | Read | |||
| Voltage Line L2 | V | Read | |||
| Voltage Line L3 | V | Read | |||
| Solar Generation Today | kWh | Read | |||
| Solar Generation Total | kWh | Read | |||
| Load Consumption Today | kWh | Read | |||
| Load Consumption Total | kWh | Read | |||
| Import Energy Today | kWh | Read | |||
| Import Energy Total | kWh | Read | |||
| Export Energy Today | kWh | Read | |||
| Export Energy Total | kWh | Read | |||
| System State | Read | ||||
| Fault 1 | Read | ||||
| Fault 2 | Read | ||||
| Fault 3 | Read | ||||
| Fault 4 | Read | ||||
| Fault 5 | Read | ||||
| Fault 6 | Read | ||||
| Fault 7 | Read | ||||
| Fault 8 | Read | ||||
| Fault 9 | Read | ||||
| Fault 10 | Read | ||||
| Fault 11 | Read | ||||
| Fault 12 | Read | ||||
| Waiting Time | s | Read | |||
| Inverter Temperature 1 | °C | Read | |||
| Inverter Temperature 2 | °C | Read | |||
| Heatsink Temperature 1 | °C | Read | |||
| Heatsink Temperature 2 | °C | Read | |||
| Module Temperature 1 | °C | Read | |||
| Module Temperature 2 | °C | Read | |||
| Set Time Year | Write | ||||
| Set Time Month | Write | ||||
| Set Time Day | Write | ||||
| Set Time Hour | Write | ||||
| Set Time Minute | Write | ||||
| Set Time Second | Write | ||||
| Set Time Confirm | Write | ||||
| Feed-in Limitation Mode | Read and write | ||||
| Feed-in Maximum Power | W | Read and write | |||
| Parallel Control | Read | ||||
| Parallel Master Slave | Read | ||||
| Parallel Address | Read and write | ||||
| Remote Switch On Off | Read and write | ||||
| System Time Year | Read | ||||
| System Time Month | Read | ||||
| System Time Day | Read | ||||
| System Time Hour | Read | ||||
| System Time Minute | Read | ||||
| System Time Second | Read | ||||
| Serial Number | Read | ||||
| Hardware Version | Read | ||||
| Software Version | Read |
Loading registers…
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If a device is not in the library yet, we build the template for free as soon as we have the register data.
Use cases
- Show PV power per input, grid power and daily yield of a Sofar installation on a dashboard.
- Get an alert when the system state changes to a fault or a fault code register is no longer 0.
- Compare generation, import and export per day in the history to see how much solar power is used on site.
- Lower the feed-in limit remotely when the grid operator or a contract asks for it.
- Spot a failing string by comparing the voltage and current of the two PV inputs over time.
Installation
Switch off the inverter and connect a twisted pair from the COM connector, pin 1 (A+) and pin 4 (B-), to the RS485 port of the ModbusCloud Gateway; fit 120 ohm between pins 2 and 3 at the end of the bus.
Check on the inverter display that the RS485 address is unique on the bus and the speed is 9600 baud.
In ModbusCloud, add a Modbus device with protocol RTU, the inverter address, 9600 baud and 8N1, and import this template.
Switch the inverter back on and check that the RS485 symbol appears on its display and that Grid Frequency shows about 50 Hz.
Things to watch for
The inverter does not answer. What should I check?
Check address and 9600 baud on the display and swap A and B if nothing comes back. Pins 1 and 2 are both A+, pins 3 and 4 both B-. Only one Modbus master can poll the inverter at a time, so disconnect any other RS485 reader.
Why are the PCC values and import and export counters zero?
These values come from an energy meter at the grid connection point that the inverter reads. Without a meter connected to the inverter, only the output values of the inverter itself are filled.
A fault code register shows a number that is not in the list. What does it mean?
Each fault register is a bitfield: every bit is one fault, and when several faults are active their values add up. Split the number into powers of two to find the active faults.
Can I change the feed-in limit from ModbusCloud?
Yes, the feed-in mode and limit and remote on/off are writable. Writing is off per gateway by default; request it for the gateway in the portal. Write the mode and the limit together and check the result by reading both back.
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