KNX Core: Interoperability

Interoperability has always been the cornerstone of the KNX standard. Having the opportunity to select from devices and components offered by over 500 KNX manufacturers is the major reason that many smart building vendors, planners, architects and installers have been choosing to base their solutions on KNX for more than 3 decades.

 

Apart from the compatibility aspect of the hardware, the high level of standardardization offered by the installer platforms, in particular KNX’ ETS package, a manufacturer independent configuration tool, enables installers to work with powerful, standardized software. ETS also includes a marketplace for devices, and can be extended with apps so that installers can use one tool for all their needs.

 

KNX has always enabled installers to emphasize flexibility with creative and sophisticated building automation solutions, while not being hindered by issues of compatibility or limitations of the installation platforms.

 

KNX going IP

KNX has primarily operated over twisted pair cabling systems, allowing for large installations. However, the larger these installations become, servicing and maintaining the installation grows more complex. Early on, KNX began looking for additional means of transporting the KNX data and leveraging other network protocols, which resulted in the early KNXnet/IP specification. This is a simple approach that packs the KNX data telegrams and sends them over IP-based networks. All while still being interoperable with existing KNX installations that use traditional wiring.

 

While this is a step in the right direction, the KNX Association wanted to further extend its efforts to embrace the full potential of “going IP.” This fueled the KNX IoT effort, which is now available as the latest development in the growing list of KNX solutions. The KNX IoT open source stack is available online. It fully complements the other choices that KNX installers have and will retain going forward, including the classic KNX TP wiring and RF methods. KNX IoT aims to enhance the way KNX is integrated at the IP level, by embracing well established mechanisms from the IP world, from routing to the strongest levels of security. And the entire network structure is based on the latest version of the IP protocol: the versatile and future proof IPv6.

 

Data Interoperability enabled by KNX IoT 3rd Party API

While the traditional KNX IP solution meant that substantial levels of the installation were based on company specific implementations, particularly related to the software clients, KNX IoT aims to further enhance KNX’ traditional strengths in compatibility, even further enhancing interoperability.

 

The new KNX IoT 3rd Party API was developed as a standardized, secure and rich way to create a data driven infrastructure. It offers multitudes of opportunities to create, receive, send and interpret data by, from and to KNX devices on the network. It adds a new level of abstraction to the data that is being produced by a KNX installation, and even specifies the semantic information of KNX devices, so that it can easily be read and interpreted by KNX IoT software clients. And because KNX IoT 3rd Party API clients need to use OAuth2.0 as part of the authentication process, the highest levels of security will be guaranteed.

 

KNX IoT Point API Enables IPv6 and Thread

The other core component of KNX IoT is the KNX IoT Point API. This is the protocol stack that runs on a KNX IoT device and is connected via the IPv6 protocol with the rest of the network and KNX installation. The lower layers of this stack are not KNX specific, but based on universal IPv6 principles.

 

All of these KNX IoT Point devices can be used in the same installation with IPv4 based KNXnet/IP devices, and even non-IP based KNX devices using the traditional TP wiring or wireless RF solution. For this, KNX IoT routers can simply be deployed. This gives a system architect or planner the ultimate freedom in choosing the network solution that works best in a particular situation, all while remaining fully compatible with the KNX ecosystem.

 

Thread Networking Benefits

The KNX IoT Point API is what allows KNX IoT devices to work with Thread, bringing all the benefits that Thread networking has to offer. First and foremost is the mesh capability, enabling the coverage of large areas or big buildings, without complex wiring. KNX IoT on Thread simply uses mains powered Thread devices as “extenders” for the data to reach its destination. A Thread mesh network is fully self-healing, meaning that it will adapt to changes to the infrastructure, such as devices being removed or replaced, without any dedicated actions.

 

For the first time, Thread's lower power design allows for battery operated KNX devices such as window contacts and sensors to work for up to ten years on a single battery, necessary for practical usage in large building installations. The global 2.4 GHz band that is used by a Thread network means that manufacturers can make a single device SKU for worldwide usage, and it also greatly simplifies component selection for system architects and planners.

 

Extended Lifecycle and Reduced Cost Footprint

Furthermore, KNX IoT will leverage the strongest security methods, all designed to work in tandem with the models security principles and encryption mechanisms that are a required component of a Thread network. This includes mandatory over-the-air update capabilities.

 

This demonstrates that the focus has expanded from commissioning and installation benefits to extending the life cycle of a building. From installation in the building, to maintenance and disposal, KNX IoT and Thread offer the most cost effective footprint that is possible with a KNX installation to date.

 

Open Source Project Launched for KNX IoT Point API

To ease the development of KNX IoT Point devices, a KNX IoT Point API open source stack is available that can be used as a first step. The project is sponsored by the KNX Association and is being developed by a group of KNX IoT expert companies.

 

The repository page for the KNX IoT Point API open source project contains a lot of background information about the technical implementations of the API, the various ways the software can be built on a variety of operating system platforms, and how the stack can be applied to a dedicated hardware platform, a KNX IoT Virtual installation or even Raspberry Pi.

 

Cascoda launches KNX IoT API Development Kit

To support the development of KNX IoT devices that can run on IPv6 networks including Thread, development hardware kits are becoming available.

 

Wireless systems developer and chip manufacturer Cascoda will release their KNX IoT Point API development kit this fall. It is based on the KNX IoT Point API open source project, completely adapted and ported to their hardware, so developers can skip this customization process altogether and focus on product specific functionality.

 

Cascoda’s development kit offers a configurable dashboard, and brings a Thread Border Router capability alongside Thread, Wi-Fi and ethernet connectivity. The hardware offers battery charging, programmable buttons and LEDs, e-paper display integration, and a library of sensor and actuator plugin boards to adapt a project to a specific use case.

 

KNX IoT Ready for Business

KNX device manufacturers are offered the components to quickly jump on the KNX IoT products bandwagon, while KNX planners and installers are given yet another powerful set of technology solutions to fulfill their client’s wishes and needs in totally new and creative ways.

 

The comprehensive KNX IoT specification, the powerful KNX IoT 3rd Party and KNX IoT Point APIs, the availability of open source software stacks and flexible hardware development kits, all mean that KNX IoT is ready for business. Thread’s long range, low power self-healing mesh networking technology further extends the possibilities, truly opening up the power and flexibility of KNX IoT.