Modbus to M-Bus with PiiGAB M-Bus 900S  

The application Modbus2MBus for the PiiGAB M-Bus 900S is developed to enable communication via M-Bus with Modbus units on your existing M-Bus network. Your Modbus units will by using the application Modbus2MBus be seen as a virtual M-Bus meters on your M-Bus network. This will give you a unique opportunity to use both M-Bus and Modbus at the same M-Bus network.

The application Modbus2MBus is ordered as an addition to our gateway PiiGAB M-Bus 900S. You can connect up to 32 Modbus units per gateway/converter. For example, you can communicate with meters, heat pumps, cooling units, PLC, distributed I/O units etc. that are using the Modbus protocol. The gateway works as a translator between the two protocols. This allows M-Bus based systems to communicate directly with Modbus units.

Read Modbus meters and M-Bus meters simultaneously

Extend the M-Bus network with Modbus

In order to connect the Modbus units to your M-Bus-system you have to start the process from the Modbus units. The first step is to put in the address of your Modbus unit and then the M-Bus address, primary or secondary, it should be connected to. The next step is to put in what Modbus register you want to read and that is when the first M-Bus object is created automatically. The system adds on at the pace you are configuring the Modbus registers that you wish to read out. It is also possible to complement your Modbus register with more advanced M-Bus properties, such as what text and kind of value it should have (VIB), as well as which tariff the value should belong to etc.

Communication and verifying

Via the M-Bus command SND_NKE, the connection verifies the communication with the Modbus slave. When the M-Bus client sends commands such as SND_NKE to an M-Bus meter, the meter responds with E5 when contact has been established. To keep the same structure with virtual M-Bus meters the SND_NKE question is forwarded to the Modbus slave. When this unit answers in a correct manner the PiiGAB M-Bus 900S forwards the answer as E5 to the M-Bus client. This gives you a safe and reliable application.



It is possible to save your configured Modbus meters as templates to later reuse them in other projects. The templates contain all necessary connections and properties belonging both to the Modbus slave and the virtual M-Bus meter

Advantages with Modbus2MBus

  • Connect up to 32 Modbus units.
  • Each Modbus unit acts like a virtual M-Bus unit.
  • The possibility to write to the Modbus units via M-Bus.
  • Use the manufacturer number on your Modbus unit as the secondary address in M-Bus.
  • Supports both primary and secondary addressing via M-Bus.
  • Verify contact with the Modbus slave via the M-Bus command SND_NKE.
  • Save and import virtual meters as templates.
  • Mix M-Bus and Modbus meters.
  • Simplicity to change the order of the M-Bus objects.
  • Works together with most M-Bus clients.
  • Exporting the configuration to a text file for an easier configuration of the M-Bus client.
  • Supports posting of Modbus and M-Bus data via QuickPost.