Solis inverter via Modbus RTU (RS-485) connection
This guide describes step by step how to connect a Solis inverter to the Currentt Navigator via Modbus RTU over RS-485.
Also see: For connection via the network (Modbus TCP), see the guide Solis Modbus TCP.
Support for Solis is currently in beta. If anything does not work as expected, please contact customer support.
✅ Compatible models
| Model | Power | Type |
|---|---|---|
| S6-EH3P10K | 10 kW | Hybrid (three-phase) |
| Other S6-EH hybrid models | to be determined | Hybrid |
🧰 Requirements
- Currentt Navigator Pro (with RS-485 Modbus connection)
- CAT6 SFTP cable (shielded, twisted pair)
- COM connector of the inverter (Exceedconn EC04681-2014-BF, supplied with the inverter)
- Phillips screwdriver
⚠️ 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 on the underside of the inverter.
- Take the supplied COM connector (Exceedconn EC04681-2014-BF)
- Lead the CAT6 SFTP cable through the connector
- Connect the wires according to the pin definition below:
| Pin | Signal | Connection on the Currentt Navigator |
|---|---|---|
| 2 | Ground (cable shield) | G (see ground connection) |
| 3 | RS485A+ | A+ |
| 4 | RS485B− | B− |
- Fit the COM connector onto 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
Always use one wire pair from the same twisted pair for RS485A+ and RS485B−. 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 address
You set the Modbus address via the display of the inverter.
- On the display, open the Settings menu
- Choose Set Address
- Set the address to 1 (default)
- Confirm the setting
With multiple Solis 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 baud rate of the Solis RS-485 port is fixed at 9600 and cannot be changed. Therefore set 9600 in the Currentt Navigator as well.
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 Solis
- 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 (Exceedconn EC04681-2014-BF) |
| Pin assignment | Pin 3 = RS485A+, pin 4 = RS485B−, pin 2 = ground |
| Cable | CAT6 SFTP (shielded, twisted pair) |
| Modbus address | 1 (default, configurable 1 – 247) |
| Baud rate | 9600 (fixed) |
| Data bits | 8 |
| Parity | None (disable) |
| Stop bits | 1 |
🛟 Troubleshooting
| Problem | Possible cause | Solution |
|---|---|---|
| No connection | A+ and B− swapped | Check the polarity; pin 3 is A+, pin 4 is B− |
| No connection | Wrong baud rate | Set the baud rate in the Navigator to 9600; on Solis this is a fixed value |
| No connection | Wrong Modbus address | Check the address via Settings → Set 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 one wire pair from the same twisted pair for A+ and B− |
| 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 |
| Power is not limited | Battery not yet fully charged | On Solis, the inverter only curtails PV production once the battery is fully charged (100%) |