The Desigo building automation and control system offers multiple options to integrate M-bus devices. M-bus devices and their data points are mapped to BACnet objects. In this way, M-bus meter data points can be made available to other controls and BACnet clients. The system offers different ways to integrate M-bus devices for online and offline engineering.

Onboard M-bus interface

 

Connect up to 4 M-bus devices to your automation station directly. The onboard interface is compliant to EN 13757-2. Baud rates of up to 9600 bit/s are supported.

The following system controller and automation stations can be used as M-bus manager to integrate M-bus devices directly:

  • PXC5.E003
  • PXC5.E24
  • PXC7.E400

Onboard M-bus interface in combination with M-bus repeater

 

Connect up to 60 M-bus devices to your automation station via an M-bus repeater. The onboard interface is compliant to EN 13757-2. Baud rates of up to 9600 bit/s are supported.

The following system controller and automation stations can be used as M-bus manager to integrate M-bus meters connected via an M-bus repeater:

  • PXC5.E003
  • PXC5.E24
  • PXC7.E400

M-bus repeater used in the configuration example: Siemens, WTV531-GA5060 (A6V10923897)

 

 

Connect up to 250 M-bus devices to your automation station via an M-bus repeater. The onboard interface is compliant to EN 13757-2. Baud rates of up to 9600 bit/s are supported.

The following system controller and automation stations can be used as M-bus manager to integrate M-bus meters connected via an M-bus repeater:

  • PXC5.E003
  • PXC5.E24
  • PXC7.E400

M-bus repeater used in the configuration example: Siemens, WTX631-GA0090 (A6V11877785)

M-bus devices integration via RS485 level converter

 

Connect up to 250 M-bus devices to your automation station via an RS485 level converter. The highest available baud rate depends on the limitations of the level converter and the connected M-bus devices. The RS485 interface for M-bus supports baud rates of up to 38400 bit/s.

The following system controller and automation stations can be used as M-bus manager to integrate M-bus meters connected via an M-bus repeater:

  • PXC4.E16
  • PXC4.E16-2
  • PXC4.M16
  • PXC4.M16-2
  • PXC5.E003
  • PXC5.E24
  • PXC7.E400

Configuration examples for different RS485 level converters:

STV Electronic, MPW-2

2 M-bus devices

STV Electronic, MPW-6

6 M-bus devices

Relay GmbH, PW60

60 M-bus devices

Siemens, WTX631-GA0090

250 M-bus devices

 

To be considered for all M-bus configurations listed above:

The ABT Site engineering tool checks the number of data points and not the number of M-bus devices (for details, refer to the system limitations in this document "PXC4, PXC5, and PXC7 automation stations"). The maximal number of devices per network depends on the individual load of each device and the given power supply by the M-bus manager or level converter. The maximum number of M-bus devices is usually defined as "simple M-bus loads à 1.5 mA".

For further information about M-bus (Meter-Bus), see https://m-bus.com/.