How to connect Sunways hybrid inverter with Reduxi controller
Integrate the Sunways hybrid inverter with the Reduxi Controller via Modbus RTU. Maximum flexibility and cost and energy reductions of up to 30%.
1 Technical documentation
Sunways documents are available in the Sunways download center. The user manual of the STH 15~33KTL hybrid inverter is an example.
- Sunways download center – Manuals and datasheets for Sunways inverters
- STH 15~33KTL-HT user manual (PDF, EN) – User manual for the 15 to 33 kW hybrid inverter
2 Required equipment
You need these components:
- Reduxi Controller
- Sunways hybrid inverter with RS485 (EMS) interface
- RS485 cable between the inverter and the Reduxi Controller
- Laptop or tablet with internet access to configure the device in Reduxi
3 Connect the Reduxi Controller to the Sunways inverter
The physical connection is required because Modbus RTU is used to access the hybrid inverter interface.
The picture shows the EMS communication wiring from the Sunways manual (Figure 4-36). Reduxi takes the role of the EMS. The RS485_A and RS485_B terminals of the inverter connect to the RS485 terminals of the EMS.
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Diagram of the EMS communication wiring between a Sunways hybrid inverter and an EMS, in an orange rounded frame, caption below: Figure 4-36 EMS communication wiring diagram. Left box Inverter with two RJ45 ports labelled METER and EMS, and two terminal blocks below them labelled DRED (left) and COM (right). On the COM block two terminals are labelled RS485_B and RS485_A. Right box with a terminal block labelled EMS, with two terminals labelled RS485_B and RS485_A. Two lines run from the inverter terminals RS485_B and RS485_A to the EMS terminals RS485_B and RS485_A (the exact routing of the two lines is hard to follow in the image).
4 Log in to the Reduxi web interface
You can open the Reduxi web interface in two ways:
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Screenshot of three Reduxi mobile app screens side by side, with cyan boxes and number badges 2 to 4. Left screen (dashboard, dark theme): menu icon at top left marked with a box and badge 2; 'reduxi' logo; tabs 'Real time data' (active) and 'Statistics'; price 5.79 € and temperature 3.2 °C; energy flow diagram with a house in the centre (-1.25 kW) and icons with values 69.0 W, 1.3 kW, 1.1 kW (red ring), -165.0 W with 97 % (red ring) and 0.0 W values at the bottom; tabs 'Power' and 'Energy'; bottom navigation: Dashboard, Diagnostics, Device control, Settings. Middle screen (side menu): 'reduxi' logo, 'Number of locations: 1233', heading 'Reduxi device management', entries '+ Add Reduxi location' and 'Reduxi devices' (marked with a box and badge 3), then 'My profile' and 'About app'. Right screen (device page): Back; picture of a black Reduxi controller with two Ethernet ports; status 'Connected'; card 'Update available': 'New update is available for your Reduxi device.' with button 'Download and install update'; card 'Connect to configurator': 'Tunnel connection enables remote access to your Reduxi configurator, without need to be connected to the same local network.' with button 'Activate tunnel connection' (marked with a box and badge 4); card 'Unit details' with field 'Unit ID'.
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Screenshot made of two parts side by side. Left part: Reduxi mobile app screen on a dark background. Top: Back button; picture of a black Reduxi controller with two Ethernet ports and a terminal block; status 'Connected' with a Wi-Fi icon. Card 'Update available': 'New update is available for your Reduxi device.' with button 'Download and install update'. Card 'Connect to configurator' with a key icon: 'Tunnel connection enables remote access to your Reduxi configurator, without need to be connected to the same local network.' and button 'Open configurator', marked with a cyan box and number badge 5. Below: card 'Unit details' with a field 'Unit ID' (value not visible). Right part: Reduxi Configurator opened in a browser, marked with a cyan frame and number badge 6. Header: back arrow, 'Tunnel connection', reload icon. Left sidebar with icons (lightning, chip, lightning bolt, bar chart, gear). Page 'Home' with a green link icon. Green notice: 'New patch available. Click here to apply.' with a close X. Time 09:12:56. Energy flow diagram with a house in the centre (1.700 kW) and icons for grid (0.000 kW), solar (1.700 kW), battery (green, 0.000 kW and 0.800 kW), a device at left (0.900 kW), electric vehicle and a charger or device at bottom. Label 'Energy manager' at the bottom.
http://reduxi.local. You can find the controller's IP address in your router's device list or in the Reduxi app under Reduxi devices.admin · Password: admin (factory default)Text description of this image
Screenshot of the Reduxi Configurator login page in a Chrome browser window. The address bar shows 'Not secure' and 'reduxi.local'; the address bar is marked with a cyan box and an enlarged copy of it (cyan box, text 'Not secure reduxi.local') is shown at the left, connected by a cyan line. Page background: light grey line drawing of a house with solar panels (green), a wall box, an inverter, a car and a charger. Top left: 'reduxi configurator' logo. Login box in the centre with title 'Login', a language selector (English flag, 'English'), a username field and a password field, and a dark 'Login' button.
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Screenshot of the Reduxi Configurator web interface after login, light theme. Top left: 'reduxi configurator' logo. Header bar: 'Home' at left, green 'Connected' status at top right. Left sidebar: expanded section 'Devices' with a list of entries, then collapsed sections 'Manager' and 'Configuration' and 'Settings'. Main area: energy flow diagram. House in the centre with ring, value 24.20 kW. Grid icon at top left, 24.20 kW (red dot on its line). Solar icon at top right, value '-'. Left icon (battery or device), 6.700 kW (green dot on its line). Right icons (battery storage and a device), values '-'. EV charger icon at bottom left, 31.00 kW. A further device icon at bottom right. Label 'Energy manager' below the house.
5 Add the Sunways inverter to Reduxi
After you connect the Reduxi Controller and the hybrid inverter, register the inverter as a new device.
5.1 Basic settings
Log in locally to the Reduxi Configurator on the controller (see Point 4) and press the Add device button.
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Screenshot of the left sidebar of the Reduxi Configurator. Top: reduxi logo with the text CONFIGURATOR. Collapsed sections: Devices (plus icon) and Strategies (plus icon). Below, two buttons side by side: Add device (plus icon, marked with a blue highlight box) and Add strategy (plus icon). Below them two entries: Settings and Profile. The area to the right of the sidebar is empty white.
In the first step (basic settings), select these parameters:
- Device type:
Hybrid inverter - Type:
Sunways Hybrid Inverter - Name: a name of your choice
The categories Solar power plant, Battery and Grid are preselected.
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Screenshot of the Reduxi Configurator wizard, step 1 Basic settings. Step indicator: 1 Basic settings (black), 2 Communication channel (grey), 3 Advanced settings (grey). Heading: Basic settings. Fields: Device type *: Hybrid inverter (dropdown); Type *: Sunways Hybrid Inverter (dropdown); Categories *: three tags Solar power plant, Battery, Grid (each with an x); Name *: Sunways Hybrid Inverter (input field, highlighted). Buttons: Back (left), Next (dark, right).
Press Next.
5.2 Communication settings
The second step configures the communication channel for Modbus RTU. It establishes the link between the Reduxi Controller and the Sunways hybrid inverter. The values below are the ones shown in the screenshot:
| Parameter | Value |
|---|---|
| Connection | Local serial port |
| Port |
Port 1 (the port you connected the RS485 cable to) |
| Baud rate | 9600 bits/s |
| Data bits | 8 |
| Stop bits | 1 |
| Parity | None |
| Modbus unit ID |
247 (default) |
| PV |
Yes (is PV installed on the inverter) |
| Battery |
Yes (is a battery installed on the inverter) |
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Screenshot of the Reduxi Configurator wizard, step 2 Communication channel. Step indicator: 1 Basic settings, 2 Communication channel (both black), 3 Advanced settings (grey). Heading: Communication channel and device configuration. Fields: Connection *: Local serial port; Port *: Port 1; Baud rate *: 9600 bits/s; Data bits *: 8; Stop bits *: 1; Parity *: None; Modbus unit ID *: 247 (marked with a blue rectangle); PV *: Yes (hint: Is PV installed on the inverter?); Battery *: Yes (hint: Is battery installed on the inverter?). Buttons: Back (left), Test communication, Next (dark, right).
247 by default.5.3 Test communication
Click Test communication below the communication parameters. It checks whether the Modbus RTU connection between the devices works. It reads the inverter once and saves nothing.
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Screenshot of the lower part of the Reduxi Configurator communication channel form. Fields: Modbus unit ID *: 247; PV *: Yes (hint: Is PV installed on the inverter?); Battery *: Yes (hint: Is battery installed on the inverter?). Buttons: Back (left), Test communication (marked with a blue rectangle), Next (dark, right).
The test returns one of two results:
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Screenshot of a dialog titled Test communication (close x at the top right) with green text. Content: Successful readout from device. Values: Battery active power: -450.0 W; Battery current: -1.8 A; Battery export active energy: 2493400 Wh; Battery import active energy: 2784800 Wh; Battery max. active power: 10000.0 W; Battery min. active power: -10000.0 W; Battery state of charge: 25.63 %; Battery state of health: 99.37 %; Battery voltage: 269.5 V; Error: false; Grid export active energy: 0 Wh; Grid import active energy: 0 Wh; Inverter active power: -1444 W; Load active power: 76 W; Load import active energy: 953900 Wh; Off-grid: false; PV active power: -839 W; PV current: -1.9 A; PV export active energy: 10434800 Wh; PV min. active power: -10000 W; PV voltage: 433.7 V; State name: ON_GRID. Additional parameters: GRID_POWER_ACTIVE_L1: 20; GRID_POWER_ACTIVE_L2: 12; GRID_POWER_ACTIVE_L3: 24; PV_POWER_ACTIVE_MAX: 0. Dark button at the bottom right: Close.
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Screenshot of a dialog titled Test communication with a close x at the top right. Message in red text: Unable to communicate with device. Dark button at the bottom right: Close.
If the test succeeds, press Next to continue with the advanced settings.
5.4 Advanced settings
Use the advanced settings only if the special needs of the location require it. By default, you do not need to change anything. Press Done to create the device: only Done creates it.
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Screenshot of the Reduxi Configurator wizard, step 3 Advanced settings. Step indicator: 1 Basic settings, 2 Communication channel, 3 Advanced settings (all black). Heading: Advanced settings. Each question has a toggle, all set to No: Do you want to set data saving interval? No (Default: 1 min); Do you want to set reading delay? No (Default: 1000 ms); Do you want to set writing delay? No (Default: 1000 ms); Do you want to set power generation limits and capabilities? No; Do you want to set power consumption limits and capabilities? No; Do you want to limit communication with the device to read-only? No (Default: No); Do you want to invert direction for energy import and export? No (Default: No). Dropdowns: L1 is connected to main feed: L1; L2 is connected to main feed: L2. Button: Back.
6 Check the readings
6.1 Last measurements
Check the readings under Devices – Sunways Hybrid Inverter – Last measurement in the Reduxi Configurator.
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Screenshot of the Reduxi Configurator page "Last measurements" of a DAZE charger (per the existing alt text). Card "Control type": a button group Auto (selected, turquoise), Manual, Off, Boost; timestamp 02. 10. 2024 15:47:17. Card "Current": Current L1 0.00 A; Current L2 0.00 A; Current L3 0.00 A; Max. current per phase 32.00 A; Per phase current setpoint 6.00 A (each with timestamp 02. 10. 2024 15:47:17). Card "Power": Import - active power 0.0 kW; Max. active power 22.1 kW; Min. active power 0.0 kW (timestamp 02. 10. 2024 15:47:17). Card "Energy": Import active energy 5,104.5 kWh (timestamp 02. 10. 2024 15:47:17). Card "Other": Communication error OFF (timestamp 02. 10. 2024 15:47:16); Control type AUTO; Error OFF; State name CABLE_UNPLUGGED... (text cut off with dots); timestamps 02. 10. 2024 15:47:17.
Once the device is added in the Reduxi Configurator, you can also monitor it in the Reduxi cloud application.
✓ Summary
Preparation (Points 1–2): Get the Sunways documents. Prepare the Reduxi Controller, the Sunways hybrid inverter with RS485 interface and the RS485 cable.
Sunways inverter (Point 3): Connect the RS485 terminals of the inverter to the Reduxi Controller. Reduxi takes the role of the EMS.
Add to Reduxi (Points 4–5): Log in to the Reduxi Configurator and add the device. Enter the Modbus RTU settings, test the communication and press Done.
Go live (Point 6): Check the readings under Last measurement. Monitor the inverter in the Reduxi cloud application.
→ Common issues
| Issue | Solution |
|---|---|
| Test communication fails | Check that the Port setting matches the Reduxi port the RS485 cable is connected to. Check the Modbus unit ID (default 247). |
| PV or battery values are missing | Set PV and Battery to Yes only if PV or a battery is installed on the inverter. |
| Open configurator does not open or stays empty | The tunnel is not active yet. Wait about 30 seconds and check that the controller is online. |
Login with admin is rejected |
The password was changed during installation. Ask the installer. The Reduxi account password does not work here. |
reduxi.local does not load |
Your device is not in the same network as the controller. Use the IP address or the tunnel connection. |
| Communication test fails, device shows offline | Check reachability, IP address / port / unit ID, and that the protocol is enabled on the device. |