How to connect Iskra IE38Mx smart energy meter with Reduxi controller
Connect the Iskra IE38Mx smart energy meter to the Reduxi Controller via Modbus RTU (RS485).
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Product photo of a white DIN-rail energy meter on a white background. Top: terminals L1o, L2o, L3o (outputs), a row labelled 'S0', '+', '-', 'COM', 'A', 'SC', 'B'. Front: 'Iskra' logo, model 'IE38MD', blue LCD with two lines: lock symbol '1' 1.8.0 kWh, value 739.0; lock symbol '2' 2.8.0 kWh, value 6.0. At the left a vertical text '1 imp/Wh, Cl. B, SN' with a serial number (small); at the right a wireless symbol, a 'YAVI' logo and small print about 3 x 230/400V 50/60Hz. A grey square and a hand or touch symbol are at the lower left of the front. Bottom: terminals Ti, N, L1i, L2i, L3i.
1 Technical documentation
Instructions for connecting and configuring the meter are on the manufacturer web page: https://www.iskra.eu/en/Smart-energy-meters/Energy_meter_IE38Mx_1/
- Iskra IE38Mx product page – Variants IE38MS, IE38MM, IE38MD and IE38MF, interfaces and downloads
- Users manual IE38Mx – Connection, communication settings and Modbus communication protocol (Appendix A)
- Data sheet IE38Mx – Technical data
- Smart Meter IE38Mx (brochure) – Product overview
2 Required equipment
You need the following components:
- Reduxi Controller
- Iskra IE38MD energy meter (the IE38Mx variant with the Modbus RS485 interface)
- RS485 cable between the meter and the Reduxi Controller
- Laptop or tablet with internet access to configure the device in Reduxi
3 Connect the meter to the Reduxi Controller
3.1 RS485 terminals on the meter
The RS485 connection on the IE38MD is labelled A, SC (shield) and B in the manufacturer manual. The connection diagram is in the users manual (see Point 1).
4 Check the communication settings on the meter
The IE38MD uses Modbus RTU on RS485. The factory settings from the manufacturer manual:
| Parameter | Factory setting |
|---|---|
| Protocol | Modbus RTU |
| Speed |
115200 bit/s (1200 to 115200 bit/s possible) |
| Frame |
8, N, 2 (8 data bits, no parity, 2 stop bits) |
You can change the address, speed, parity and stop bits on the meter display (Settings – Communication) or with the Iskra MiQen software (version 2.1 or higher).
5 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.
6 Add the meter to Reduxi
Use these steps to add a new meter or to edit an existing one.
6.1 Basic settings
Log in to the Reduxi Configurator via the browser (see Point 5), click + Add device and enter the basic settings of the meter.
6.2 Communication settings
Select the communication channel and enter the device configuration:
| Parameter | Value |
|---|---|
| Modbus unit ID | Normally 1 is used. The value must match the Modbus address set on the meter. |
Then enter and choose the advanced settings.
6.3 Test communication
Click Test communication at the bottom of the wizard. It reads the Iskra IE38Mx once and saves nothing. If the test succeeds, click Done: only Done creates the device.
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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'.
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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.
7 Check the readings
7.1 Last measurements
After communication is established, check the values under Devices – Iskra IE38Mx in the Reduxi Configurator.
✓ Summary
Preparation (Points 1–2): Open the manufacturer documentation. Prepare the controller, the IE38MD meter, the RS485 cable and a laptop or tablet.
Iskra IE38MD (Points 3–4): Connect the RS485 terminals A and B. Check address, speed, parity and stop bits on the meter.
Add to Reduxi (Points 5–6): Log in to the Reduxi Configurator. Add the device, enter the Modbus unit ID and test communication.
Go live (Point 7): Check the last measurements under Devices.
→ Common issues
| Issue | Solution |
|---|---|
| No data from the meter | The Modbus unit ID, speed, parity and stop bits in Reduxi must match the settings on the meter. |
| Several meters on one RS485 line | Each meter needs a unique Modbus address. Unconfigured meters share the factory address 33. |
| 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. |