Compatible IMT irradiance sensor, RS485 connection and commissioning steps for solar monitoring.
Measure the sunlight reaching your PV installation with the IMT Si-RS485TC-T-MB. This sensor reports solar irradiance in W/m², providing context alongside solar-production measurements.
| Sensor manufacturer | Compatible sensor model | Data connection | Measured quantity |
|---|---|---|---|
| IMT Technology (Mencke & Tegtmeyer) | Si-RS485TC-T-MB | RS485 / Modbus RTU | Solar irradiance in W/m² |
Find the sensor in the commissioning wizard using this selection:
Energy meter → IMT → SiRS485TCTMB-Pyranometer
Although it appears in the Energy meter category, it measures sunlight, not electrical power or energy. It does not replace the grid meter used for import/export measurement. The supported measurement for this connection is irradiance; cell temperature and optional temperature or wind sensors are not read by this integration.
The sensor's factory communication settings are:
| Setting | Factory value |
|---|---|
| Communication protocol | Modbus RTU |
| Default Modbus address | 1 |
| Default serial speed | 9600 baud |
| Serial framing | 8 data bits, no parity, 1 stop bit (8N1) |
If the sensor has already been configured, use its actual settings. Each sensor on the same RS485 bus needs a unique Modbus address; supported addresses are 1–247. This model uses RS485, not a direct Ethernet/Modbus TCP connection.
Scan in daylight
A reading of 0 W/m² can prevent this sensor from being detected. If it is not found at night or while covered, repeat the scan with light on the sensor before changing the wiring or settings.
Irradiance helps distinguish reduced solar production caused by less sunlight from changes that need further investigation. It is a measurement per unit of area, not the installation's total power in kW or generated energy in kWh.
For the wider monitoring overview, see Meters, sensors, gateways & building systems. Sensor communication details are available in the IMT Modbus specification.