KNX Stack IP

The internet protocol IP will be treated as a stand-alone media within KNX and will be considered equal to Twisted Pair (TP), Power Line (PL) and Radio Frequency (RF). KNXnet/IP allows transferring KNX features like configuration modes and inter-working to the IP world. It opens the door to top level communication in buildings (e.g. Telecommunication, Multimedia, etc.) and enables external connections to the KNX installation via the internet. The future belongs to hierarchical topologies: Ethernet will go on to establish a powerful backbone and connection for complex (IP only) devices.

Our KNX Stack IP is suitable for implementing KNX devices, which are connected to the KNX network over IP respectively Ethernet as medium. The software contains a complete KNX device model. Thereby KNX devices on IP can be programmed with ETS-Software.


Firmware Architecture

The System-Software for a KNXnet/IP device indeed consists of two protocol stacks. For the communication over Ethernet an IP stack with UDP (User Datagram Protocol) is needed, as the KNXnet/IP is based on connectionless communication. Numerous operating systems like Linux or Windows CE® already provide an IP-stack. The KNX stack is put on the IP/UDP stack and uses it as interface to the network. The protocol layers of the OSI/ISO reference model and additionally the particular device model with appropriate management procedures are contained in the KNX stack.

For KNX IP only devices the device model 5705 has been defined. This device model is lean on the model 0705 of Twisted Pair. Up to 255 group objects are provided and it supports an area for thousands of parameters.

The device application uses the API (Application Programming Interface) of the KNX stack, in order to communicate on group object level with the KNX network.

As system provider for KNX we offer different solutions for developing and producing KNX IP devices in an efficient way. Every existing IP stack, e.g. of Linux, may be used together with the KNX stack IP. Furthermore, we provide a special IP stack, which especially has been developed for small platforms without an operating system (OS).

Hardware architecture

In essence, an IP node consists of an Ethernet controller and a micro controller. The decision for a particular micro controller depends on required computing power for the device. In principle it is possible to implement the KNXnet/IP protocol on an 8-Bit micro. If necessary for the application, more powerful micro controllers may be required. Numerous controllers provide an interface for Ethernet on the chip, so only the physical layer has to be added. For higher demands on performance, platforms from the PC sector are interesting. 

Weinzierl Engineering offers reference designs based on Atmega128 (8-Bit) respectively on ARM7 (32-Bit). Power supply over “Power over Ethernet” (PoE, IEEE 802.3af) is also integrated in the reference design. For more complex devices with Linux operating system an implementation available is available as well. 

Tool environment

The core of our tool environment is Net’n Node, a powerful bus monitor and analyzer to assist you during development and test. As additional interfaces KNXnet/IP Tunneling and Routing are supported now. In addition, this program creates the s19 files needed for import into the ETS database. The program TraceMon displays additional debug information of the firmware.


With our software products you get extensive support and 2 years of guarantee. We will advise you on your system architecture and give you full support during your development. 

Development services

If you are interested in individual solutions or complete device development, we offer application development services including hardware design, programming and ETS database integration. With broad experience in the development of bus components and systems, we are looking forward to finding solutions tailored specifically to your requirements. Of course also KNX product certification is included in our service. If you have any questions on the development kit and our services, please do not hesitate to contact us.