SolaX inverter via Modbus RTU (RS-485) connection
This guide describes step by step how to connect a SolaX inverter to the Currentt Navigator via Modbus RTU over RS-485.
Also see: For connection via the network (Modbus TCP), see the guide SolaX Modbus TCP.
✅ Compatible models
| Model | Power | Type |
|---|---|---|
| X1-MINI G3 | 0.6 – 3.6 kW | Single-phase |
| X1-MINI G4 | 0.6 – 3.3 kW | Single-phase |
| X1-BOOST G4 | 2.5 – 6 kW | Single-phase |
| X1-SMART G2 | 5 – 10 kW | Single-phase |
| X3-MIC G2 | 3 – 15 kW | Three-phase |
🧰 Requirements
- Currentt Navigator Pro (with RS-485 Modbus connection)
- CAT6 SFTP cable (shielded, twisted pair)
- RJ45 connector for the COM port of the inverter
- Crimping tool for RJ45 connectors
⚠️ Safety warnings
Always switch off the inverter before making the communication connection. Set the DC switch to OFF and switch off the AC side in the distribution board.
🪛 Installation instructions
Step 1: Switch off the inverter
- Set the DC switch on the inverter to OFF
- Switch off the AC side in the distribution board (circuit breaker)
- Wait at least 5 minutes so the capacitors can discharge
- Check that the display of the inverter is off
Step 2: Connect the RS-485 cable
The RS-485 connection runs via the COM port (RJ45) on the underside of the inverter.
- Crimp an RJ45 connector onto the CAT6 SFTP cable using the T568B wiring scheme
- Connect the wires according to the pin definition below:
| Pin | Wire (T568B) | Signal | Connection on the Currentt Navigator |
|---|---|---|---|
| 4 | Blue | RS485A+ | A+ |
| 5 | White/blue | RS485B− | B− |
| — | Shield | Ground | G (see ground connection) |
- Insert the RJ45 connector into the COM port of the inverter
- Connect the other end to the RS-485 Modbus connection on the Currentt Navigator using the supplied plug-in connector
Of the eight wires in the RJ45 connector, only pin 4 and pin 5 are used for Modbus. Together these two form the blue twisted pair. The remaining pins of the COM port serve other functions (such as meter or DRM) and should be left alone.
Always use one wire pair from the same twisted pair for RS485A+ and RS485B−. With T568B this is the blue pair (pins 4 and 5). Using two wires from different pairs leads to communication errors.
Swapping A+ and B− leads to communication errors. If you cannot establish a connection, swap the two wires.
Connect the ground (GND) on one side only: either to the Currentt Navigator or to the device — but never on both sides. Connecting ground on both sides can cause a ground loop, leading to communication errors.
Step 3: Switch on the inverter
- Switch on the AC side in the distribution board
- Set the DC switch on the inverter to ON
- Wait until the display of the inverter has started up
Step 4: Check the Modbus settings
You set the Modbus address and the baud rate via the display of the inverter.
- On the display, open the Settings menu
- Choose Advanced Settings and enter the password 2014
- Choose Modbus
- Check that the settings are as follows:
| Setting | Value |
|---|---|
| Baud Rate | 9600 (default) |
| Address | 1 (default) |
- Confirm the settings
With multiple SolaX inverters on the same RS-485 bus, each inverter must have a unique Modbus address (for example 1, 2, 3). Set this via the display of each inverter.
The models described here (X1-MINI, X1-BOOST, X1-SMART and X3-MIC) use 9600 baud. Other SolaX series may use a different baud rate. Always check the value on the display and set the same value in the Currentt Navigator.
Step 5: Configuration in the Currentt Navigator
After connecting the RS-485 cable, the inverter must be added in the Currentt Navigator.
Via the installation wizard (recommended)
- Click the settings icon (top right of the screen)
- Choose Installation wizard
- Follow the steps on the screen
Manual configuration
- Click the settings icon (top right of the screen)
- Go to Components
- Click the + button in the Inverters section
- Select SolaX
- Under Communication, enter the connection details:
| Parameter | Value |
|---|---|
| Physical connection | RS-485 |
| Modbus address | 1 (default) |
| Baud rate | 9600 |
| Parity | Disable (no parity) |
- Click Save
🔚 Termination resistor
The RS-485 connection on the Currentt Navigator Pro contains an internal 120Ω termination resistor, which can be enabled or disabled via the software. It is enabled by default. See RS-485 Modbus.
📋 Settings summary
| Parameter | Value |
|---|---|
| Connection | RS-485 (Modbus RTU) |
| Protocol | Modbus RTU |
| Inverter port | COM (RJ45) |
| Pin assignment | Pin 4 = RS485A+, pin 5 = RS485B− |
| Cable | CAT6 SFTP (shielded, twisted pair) |
| Modbus address | 1 (default, configurable 1 – 247) |
| Baud rate | 9600 |
| Data bits | 8 |
| Parity | None (disable) |
| Stop bits | 1 |
🛟 Troubleshooting
| Problem | Possible cause | Solution |
|---|---|---|
| No connection | A+ and B− swapped | Check the polarity; pin 4 is A+, pin 5 is B− |
| No connection | Wrong baud rate | Check the baud rate on the display via Advanced Settings → Modbus and set the same value in the Navigator |
| No connection | Wrong Modbus address | Check the address via Advanced Settings → Modbus → Address on the display |
| No connection | Parity is not disabled | Set the parity in the Navigator to Disable |
| No connection | Wires from different twisted pairs used | Use the blue pair (pins 4 and 5) from the same twisted pair |
| No connection | Wrong pins used | Only pin 4 and pin 5 of the COM port are RS-485; check the crimp order (T568B) |
| Unreliable communication | Ground connected on both sides | Connect the ground on one side only |
| Unreliable communication | Cable too long or damaged | Use a shorter cable or check for damage |
| Address conflict | Multiple inverters with the same Modbus address | Give every inverter on the bus a unique Modbus address |