KNX2: Integration of KNX with other technologies and protocols

Owned by verena.katzlinger (Unlicensed)
Last updated: Jul 29, 2016
4 min read

The summary

When we have to solve complex installations where KNX is not the only technology present, every datapoint should be integrated in a common (software) platform using IP interfaces for every technology. This strategy follows the Automation Pyramid principle and permits the twinning of all the datapoints in a common item tree, in order to link, historize and visualize in a common platform the whole project.

The best BMS Solution must acquire several data of diverse Standard Technologies using “native” drivers for building automation, access control, hotel management,… Also other protocols should be integrated using OPC Servers. And it should be capable to serve this data to different clients (web visualization, pc visualization, energy management,…).

The problem

Solutions based on the KNX standard allows us to get good and very complete automation projects in many different facilities. However, on many occasions, due to the size and / or complexity of some projects, there are certain parts that may have been defined by project and implemented with other technologies and that we must integrate into a single solution as homogeneous as possible, in order, for example to visualize all the facilities from a single point.

In these cases the name of "integrator" of solutions is justified because we do not only integrate lighting, security or shutters with KNX, but we must associate KNX variables with other standards such as BACnet or Modbus, to name two of the most other frequent standards worldwide.

This article will describe the best option that exists, in our opinion, to integrate multiple technologies into a single standard management platform, in order to be able to visualize, link and historize all the control variables of a project.

The solution

In principle, it may seem that the proper and most direct solution in these cases is the use of gateways between the different technologies. However, indiscriminate use of gateways is not justified in many cases for economic or technical reasons, because on one hand the cost can be very high if we integrate various technologies at various points in the installation and on the other hand data traffic would unnecessarily increase in the destination technology.

In our opinion, the best solution is to consider the well-known concept of the “Automation Pyramid”, based in the integration of all the technologies over an Ethernet network using IP interfaces and managing all the control variables using a BMS (Building Management Software). The automation pyramid, thus defines three levels: field, automation (Ethernet interface) and management.

 

In this case we will add to the KNX variables, already integrated by NETx BMS App for ETS  some BACnet/IP, SNMP and some Modbus TCP datapoints, to form a complete system with HVAC control, Metering, LAN monitoring, lighting and blind Automation.

The KNX integration was very easy to do, as we could demonstrate in last articles. Even easier is BACnet integration. For the NETxAutomation BMS Server, the integration of BACnet variables is automatic, as it uses a self-discovery tool, as you can see in the pictures below:

 

 

 

After all the configurations, as a result we can see first all the available devices (IP gateways in the different technologies).

 

 

And also all the different datapoints from KNX, BACnet, Modbus and SNMP systems in a structured item tree, as we can see in the next picture.

 

 

Now, we can consider all this items as “brothers” so we can do several things with them, like e.g. virtual links between BACnet and KNX variables (see image 6), complex tasks using (LUA) scripts or just a visualization of several items from different technologies in the same screen.

 

 

 

Other advantage of the item tree that contains datapoints from different technologies is that we can do complex logic between them using X-LOGIC module as shown in the next image: