Smart Building - Building Automation

Efficient heating, cost savings

But above all, the family man wants to automate the heating system: "I was actually interested in heating as efficiently as possible." Every now and then, people forget to turn off the heating or the temperature isn't right, and then they just turn it up. Of course, that drives up heating costs and is always a nuisance, Unger explains: "I actually didn't want to worry about the whole heating issue anymore." That's what home automation is supposed to take care of.

That's why the heating system has been connected to the home control system: "Now I'm able to query the heating and also control it dynamically - depending on the demand for heat in the house."

The road to the self-networked house was not easy, however. Initially, the computer scientist used Raspberry Pi-based microcomputers. Björn Unger experimented - quite successfully - with various derivatives of these single-board computers. He used the Odroid XU4, for example, which promises a lot of computing power: "That was all right for me, too - if it ran."
That was the sticking point. Unger counted at least two total failures with the memory cards used. The systems crashed constantly. The card contents, however, could still be completely copied to a new card. The board computer then ran again - even if only until the next crash. Björn Unger got nowhere. Whether it was due to the cards themselves or whether the systems used had damaged the cards, he cannot say: "This then prompted me to look for other solutions. Of course, it's already very critical when the heating fails."

Opportunity creates partnership

Then chance comes to the cottage builder's rescue. He lays out his woes to a good friend, describing problems, symptoms and goals of his home automation solution. Since the friend works for us as a development manager, the solution was quickly found: We offer a controller for the Internet of Things - the sysWORXX CTR-700, which is a communication specialist for industrial applications and professional building management, the smart buildings. Although the controller is not designed for the "smart home" scenario and more for commercial and industrial users, it can also serve the homeowner well.

The head of development finds Björn Unger's plans so exciting that he gives him a pre-series device as a test setup. It is the perfect opportunity for the sysWORXX CTR-700 to prove itself in a non-critical scenario that closely resembles scenarios in smart building applications. This early adopter test shows on a small scale what the controller is capable of in professional smart buildings.

Controller Gatway sysWORXX CTR-700

The sysWORXX CTR-700 is a freely programmable controller with its own computing core and direct cloud connection. Measurement, open-loop and closed-loop control can be performed locally with the sysWORXX CTR-700, unlike many other solutions, and do not necessarily have to be outsourced. This pre-processing enables the conversion of various protocols and bus types in a very small space. In addition, the sysWORXX CTR-700 control offers a wide variety of interfaces and, thanks to the NXP i.MX 7 dual core processor with "Dual Cortex-A7" computing core, very good performance. The control gateway can be programmed in all common languages, a Mono library for programming in C# is pre-installed, as well as the possibility to integrate Docker containers into the system. In addition, the sysWORXX CTR-700 also understands modern communication protocols such as MQTT for inter-machine communication and the graphical IoT development tool NodeRED. OPC UA is also available for industrial applications.

In addition to classic machine control interfaces such as the CANopen and Modbus fieldbuses, the sysWORXX CTR-700 also supports new possibilities in this area such as wireless networking via Bluetooth. This impresses Björn Unger, even though he does not (yet) use these interfaces in his project. Much more important to him are the integrated eight gigabytes of eMMC memory. This permanently installed non-volatile memory is optimally adapted to the device, and Unger hopes that the system will run more stably and that crashes and failures will not occur.

Perfect integration thanks to interface diversity

With the new sysWORXX CTR-700 in his hands, Björn Unger sets about integrating the controller gateway into his home network. The challenge is to integrate the device sensibly into the existing system.

Most of the sensors and devices are connected via a port expander and the digital serial bus I²C.

The sysWORXX CTR-700 now feels at home in this heterogeneous environment. The controller gateway communicates with the home automation system via NodeRED and collects all the data from the house and the controller. Because according to Björn Unger, Loxone is not good at that. In addition, the sysWORXX CTR-700 now controls the heating system. Unger measures the flow temperature, hot water temperature, the current exhaust gas temperature and the outside temperatures that the heating system itself has determined: "The data that accumulates in the heating system, that is recorded by the sysWORXX CTR-700. All other data that accumulates in this way, I transform with the help of the sysWORXX CTR-700 and then forward it." Björn Unger plans to store the data in an Influx database and then evaluate it graphically.

Bringing the sun into the system

A solar thermal system for hot water production is to be added in the near future. Preparations are underway. Temperature sensors are already installed in the buffer tank of the heating system, which stores the heat. Communication is via a 1wire bus. When the system is installed, solenoid valves will be controlled via sysWORXX CTR-700. In the future, Unger wants to control in which cases the solar heat from the buffer tank should be used to heat the house. To do this, he wants to expand the heating control system so that he can control whether the burner should run or not: "I would like to achieve that the heating system works with forecasts depending on the weather report." Björn Unger goes into detail: "If the weather forecast says, 'Okay, there's an 80 percent chance of sunshine in the next hour,' then I'd like to ensure that the heating doesn't run for the time being. That's when I wait for the sun and use its heat for heating."

This is still a future scenario. The computer scientist still has to deal with data processing, because the data from external systems such as the weather services have to be processed and interpreted: "The big goal would be to have a platform, so to speak, that really processes raw data and then makes it usable." With the sysWORXX CTR-700, Björn Unger is certain that he already has the necessary hardware and basic software in-house.

Industrial application

With the sysWORXX CTR-700, Björn Unger achieved the stability that he tried in vain to achieve with previous systems. Transferred to industrial scenarios such as the control of smart buildings, the potential of the sysWORXX CTR-700 in terms of time savings and expansion of possibilities compared to other solutions becomes apparent. For the perfect integration of the sysWORXX CTR-700 into industrial applications, we also work with professional partners such as the IoT software manufacturer Bacsoft or the Fraunhofer Institute.