Siemens Industry Online Support
Siemens AG
Entry type: Application example Entry ID: 109739689, Entry date: 08/15/2019

Communication with S7 CPU via KNX Gateway

  • Entry
  • Associated product(s)
This application example shows, how you configure communication via a gateway between SIMATIC S7 CPU and a KNX device via the KNX bus.

Gateways enable communication between two networks/bus systems that use different communications protocols.
KNX is a fieldbus for building automation. Technically, KNX is the successor to the European Installation Bus (EIB), adding communication mechanisms and transmission media.

The task is to establish, using a KNX gateway, a communication connection between an S7 CPU via PROFINET (PN) and a KNX device via the KNX bus.

The figure below provides an overview of the automation task.

Figure 1

Representing all SIMATIC controllers, this solution uses an S7-1200 CPU. The diagrammatic representation below shows the most important components for communication between an S7-1200 CPU and a KNX network using the “Triple-X PROFINET + KNX” universal gateway from MBS GmbH.

Figure 2


The solution presented here offers the following advantages:
  • Easy adaptation to other controller families. Representing all other SIMATIC controllers with a PROFINET IO interface, this solution uses the S7-1200 CPU.
  • Easy adaptation when expanding plants. The gateway is configured directly in the gateway’s integrated web server.
  • Integration of the gateway as a PROFINET IO device via a GSD file.
  • Gateway as distributed I/O with up to 340 bytes of input and 340 bytes of output.
  • Up to 2500 data points possible for communication between PROFINET and KNX.

  Documentation (2,5 MB)
 Registrierung notwendig  109739689_KNX_S7_PROJ_V11.zip (589,0 KB) 
 Registrierung notwendig  109739689_KNX_Gateway_RestoreFile_V11.zip (4,2 KB) 
 Registrierung notwendig  109739689_KNX_ETS5_PROJ_V11.zip (1,2 MB) 

Further information
Homepage of the company MBS GmbH

Last changes
Update TIA Portal V15.1

Security information
In order to protect technical infrastructures, systems, machines and networks against cyber threats, it is necessary to implement – and continuously maintain – a holistic, state-of-the-art IT security concept. Siemens’ products and solutions constitute one element of such a concept. For more information about cyber security, please visit