Many modern buildings are equipped with air conditioning and ventilation systems that ensure optimal temperature and air quality in every room. These systems utilize sensors that measure real-time values and transmit the data to control units. There, embedded microprocessors analyze the information and compare it with target values and then issue commands to system actuators to open or close valves or ventilation dampers, for example. The results are also forwarded to a central control system. In the past, all of these components were connected to the control system by wires. Today, however, many intersystem communication networks operate wirelessly, mostly via W-LAN. Experts are still trying to come up with effective solutions for specific functions, such as the ability of devices to recognize one another in order to exchange information. With the several patents he has registered, Norman McFarland has made a major contribution to the configuration of completely wireless building automation systems.

One of his achievements involves the automatic configuration of sensors with control units – i.e. correct sensor-unit assignment. Prior to McFarland’s development, technicians had to individually configure the devices in each room by using a laptop to transfer the correct settings to the devices. This was a very complex and, above all, time-consuming process. McFarland therefore began to examine how individual system components could be automatically configured and assigned to one another by a central control system.

If devices are to be able to recognize one another, their locations in a building have to be known. As a first step, McFarland therefore attempted to come up with a method for precisely measuring the distances between the devices. He found signal travel time to be the most precise technique, and also one that was relatively easy to perform, as it only requires the calculation of the time it takes for a radio signal to travel between two measurement points. When the sensors and the control units are used as these points, it becomes possible to determine the distance between two devices.

In the next step, McFarland triangulated the distance of individual devices from one another and from specific reference points in the building. This method makes it possible to determine the position of devices in three-dimensional space.

McFarland then defined a software system whose algorithms compare the sensors’ positions as identified through triangulation with their location in the architectural plans. Once a particular device has been identified, the building’s central control system can transmit its specific spatial parameters to the corresponding system component.

As technology permits, more and more of McFarland’s inventions are being included in each successive generation of Siemens wireless products. Eventually, McFarland’s inventions will ensure that all components are automatically provided with the settings specific to the rooms in which they are located – without a technician having to manually key in this information to individual devices. This will save a lot of time and money – especially in larger buildings.

McFarland got to know the electrical inner workings of buildings at an early age, and he has been fascinated by the subject ever since. “My father was an electrician in a small town in Illinois and he used to take me along pretty often when he went to work,” he says. “By the time I was ten, I was already able to install an entire home electrical system by myself. This kind of practical knowledge is still extremely helpful to me today when I work on my inventions – especially when my colleagues and I discuss the feasibility of new solution proposals.” McFarland, who studied electrical engineering at the DeVry Institute of Technology in Chicago, has been working for Siemens in the field of building automation for  30 years in Buffalo Grove, Illinois, not far from Chicago. A system architect and hardware specialist, he spends his time trying to come up with optimal designs for different levels of building automation systems. McFarland has registered 31 inventions, which are protected in 18 IPR families and six granted individual patents. He has a grown-up daughter and likes to spend his free time golfing or exploring new cities with his wife. They especially like Paris.