Modbus Extension

The Loxone Modbus Extension is designed to integrate up to 32 devices with Modbus RTU interface.

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 absolute maximum is 1200m/3937ft.

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 on the Link Interface.

Insert and address devices

Each Modbus device must be inserted in the peripheral tree, either manually or by inserting a Template.
For each Modbus device on the same bus, a different address must be set. This must be set identically on the device itself and in Loxone Config.

The general Modbus settings such as baud rate, stop bits, and parity must be set identically on all devices on the same bus.

Now, please proceed with the Documentation of Modbus devices and Templates.

Diagnostic Inputs

Summary Description Unit Value Range
Online Status Modbus Extension Indicates whether the device can be reached by the Miniserver.
Diagnostics for Air devices
Diagnostics for Tree devices
Diagnostics for Extensions
Digital 0/1


Summary Description Unit Value Range Default Value
Serial Number Specifies the serial number of the device.
For Extensions: Enter 'Auto' to automatically pair an extension with unknown serial number.
This can only be used if there is only one Extension of the same type.
Save into the Miniserver, in order to pair the Extension.
Afterwards the program must be loaded from the Miniserver to transfer the actual serial number of the Extension into the program.
- - -
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...2 1
Parity Parity for Modbus connection.
Stop bits are set automatically: 2 Stop Bits for Parity None, 1 Stop Bit for other settings.
- - -
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 Mailer if the device is no longer available or goes offline. - - -

Safety Instructions

Installation must be carried out by a qualified electrician in accordance with the applicable regulations.

This device must be mounted on a DIN rail in an electrical distribution enclosure to ensure protection against contact, water and dust.

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


Datasheet Modbus Extension

Manual Eastron SDM630 Modbus Energy Meter 3-phase

Datasheet Modbus Energy Meter 1-phase

Datasheet Modbus Energy Meter 3-phase (discontinued)