Modbus Extension

The Modbus Extension is designed to integrate devices with Modbus RTU interface.

In Loxone Config templates for different devices are available for integration.

Datasheet Modbus Extension

Table of Contents


The Modbus Extension is installed on a DIN rail in a suitable enclosure.

Connect the power supply, Link communication to the Miniserver and the Modbus data lines.

If there is a GND terminal on the interface of the devices to be controlled, then GND must also be connected.
Modbus devices are daisy-chained, the last Modbus device must be terminated with a 120 Ohm resistor.
For wiring, a wire pair of a Cat 5/6/7 cable is recommended, alternatively another twisted pair cable can be used.

The maximum length of the Modbus depends on the baud rate. Longer wire runs result in lower possible baud rate.

The Extension starts after switching on the power supply, and the status LED will flash orange after a short time when the connection to the Miniserver is established.

Then follow the pairing procedure

Adding devices and templates

Click on the Modbus Extension and then select a device from the templates, the device settings will be applied automatically:

Then the supported sensors and actuators of the selected device are available for programming.

Finally set the Modbus address for each device in Loxone Config, which must match the respective device's address.

For additional information on how to integrate devices without template, please visit:
Communication with Modbus RTU

Diagnostic Inputs

Summary Unit
Online Status Modbus Extension Digital


Summary Description Unit Value Range Default Value
Serial Number Specifies the serial number of the device.
For Extensions: 'Auto' may only be used if only one Extension of this type is being used.
- - -
Baud Rate Baud rate in bits per second for the serial connection Bit/s 0...2147483647 19200
Stop Bits Number of stop bits used (1-2) for the serial communication - - 1
Parity Parity for serial connection - - -
Timing In Auto mode the following timing is used:
Pause: 5ms when the baud rate is smaller than 7000bps, otherwise 50bit periods are used.
Timeout: 1000ms
- - -
Monitor Online Status When selected, you will be notified via System Status or the Cloud Mailer if the device is no longer available or goes offline. - - -

Safety Instructions

The installation must be carried out by a qualified technician in accordance with all applicable regulations.

The installation requires a suitable enclosure to ensure protection against contact, water and dust.

The device must not be used as part of safety-critical systems.


Datasheet Modbus Extension

Datasheet Modbus Energy Meter 1-phase

Datasheet Modbus Energy Meter 3-phase