How to connect Carlo Gavazzi EM300/ET300 energy meter with Reduxi controller
Connect your Carlo Gavazzi EM300/ET300 energy meter to the Reduxi Controller.
Text description of this image
Photo of a light grey DIN-rail energy meter, product shot on a white background, seen slightly from above and the left. Printed on the front: 'CARLO GAVAZZI' with a red triangle logo, model 'ET340', 'Power' and 'TX' LED labels (partly cut off), '1000imp/kWh', a blue stripe across the upper front, a clear plastic optical LED window, and two RJ45-style sockets on the front. Top terminal block with three screw terminals numbered 1, 2, 3, and two small green-ringed screws labelled N and N. Bottom terminal block with three screw terminals numbered 4, 5, 6 and small numbers 7 to 12 above them. Side label with a wiring diagram: L1, L2, L3 arrows over terminals 1, 2, 3; I1, I2, I3 and N N; RS485 terminals 7, 8, 9, 10 with markings 'T', 'B+', 'A-', 'GND'; TARIFF terminals 11, 12 with a switch symbol; terminals 4, 5, 6 with arrows L1, L2, L3. A barcode with the vertical text '2005A', 'K312005A' and '2014 K3...' is on the side. The lower third of the image is empty white.
1 Technical documentation
Manufacturer documents for the Carlo Gavazzi EM300 and ET300 series (EM330, EM340, ET330, ET340):
- EM300 Series and ET300 Series Communication Protocol – Modbus RTU parameters, function codes and register tables.
- Communication protocol (Carlo Gavazzi Sweden) – Instructions on the manufacturer web page, as linked in the earlier version of this guide.
- EM330 instruction manual – Connection diagrams and parameter menu.
- ET340 instruction manual – Connection diagrams and parameter menu.
- ET340 datasheet – Specifications of the ET340.
2 Required equipment
- Carlo Gavazzi EM300 or ET300 series energy meter with Modbus RS485 interface, installed by a qualified electrician
- RS485 cable
- Reduxi Controller
- Laptop or tablet with internet access to configure the device in Reduxi
3 Connect and configure the meter
Find the instructions to connect and configure the meter in the documents of Point 1.
3.1 RS485 connection
- The RS485 interface uses the lines A-, B+, GND and T.
- Terminate the bus on the last device only: connect A- and T on that device.
- Use a signal repeater for runs over 1000 m.
- Cable according to the communication protocol: balanced pair AWG24 plus a third wire for GND.
3.2 Modbus settings on the meter
Set the Modbus parameters in the parameter menu of the meter. The values of the Modbus RTU communication protocol:
| Parameter | Values |
|---|---|
| Modbus address | 1 to 247. Default: 1
|
| Baud rate | 9.6 (default), 19.2, 38.4, 57.6 or 115.2 kbps |
| Parity | None (default) or even |
| Stop bits | 1 (default). 2 only with parity none. |
You need the Modbus address of the meter in the Reduxi Configurator. Normally, 1 is used.
4 Log in to the Reduxi web interface
You can open the Reduxi web interface in two ways:
Text description of this image
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'.
Text description of this image
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.
Text description of this image
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 meter to Reduxi
Use these steps to add a new meter or to edit an existing one.
5.1 Basic settings
Log in to the Reduxi Configurator via the browser (see Point 4) and click Add device.
In the first step, enter the basic settings of the device. Then click Next.
5.2 Communication settings
Select the communication channel. Then enter the device configuration:
| Parameter | Value |
|---|---|
| Modbus unit ID | Normally 1
|
Then enter and choose the advanced settings. Serial parameters, if requested, must match the settings of the meter (see Point 3).
5.3 Test communication
Click Test communication at the bottom of the wizard. It reads the Carlo Gavazzi meter once and saves nothing. If the test succeeds, click Done: only Done creates the device.
Text description of this image
Screenshot of the bottom button bar of a Reduxi Configurator page. Left: button 'Back'. Right: button 'Test communication' (marked with a cyan box) and dark button 'Done'.
Text description of this image
Screenshot of the Reduxi Configurator page 'Communication channel and device configuration'. Connection *: TCP/IP (dropdown). IP *: 192.168.50.243, with button 'Scan for IP'. Port *: 502, with button 'Test port'. Modbus unit ID *: 1. Buttons at the bottom: Back (left), Test communication and Done (right). The Done button is marked with a cyan box.
6 Check the readings
6.1 Last measurements
After communication is established, check the values under Devices in the Reduxi Configurator. Reduxi only reads the meter.
✓ Summary
Preparation (Points 1–2): Read the Carlo Gavazzi documents and prepare the equipment.
Carlo Gavazzi meter (Point 3): Connect the meter via RS485. Set the Modbus parameters and note the Modbus address.
Add to Reduxi (Points 4–5): Log in to the Reduxi Configurator, add the meter with its Modbus unit ID and test the communication.
Go live (Point 6): Check the readings. Reduxi reads the meter.
→ Common issues
| Issue | Solution |
|---|---|
| Test communication fails | Check that the Modbus unit ID in Reduxi equals the Modbus address of the meter (1 to 247, default 1). Check that the serial parameters match. |
| The meter does not respond on the RS485 bus | Check the RS485 lines A-, B+ and GND. Terminate the last device on the bus: connect A- and T. |
| 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. |