As technology progresses, new standards and protocols are attempting to revolutionize the building automation industry. Nowadays, many sensors and actuators are being incorporated into a typical smart home. This addition in technology calls for home automation designers to introduce an efficient way of setting up electrical connections that integrate robust electronic components.
Traditionally, a centralized star network is adopted to connect all outlet circuits, including socket and wall outlets, to a centralized distribution board where relays and programmable logic controllers (PLC) manage the turning on and off of the connection points. This electrical network system tends to be problematic in a large building connection as it requires a complex distribution board system with bulky wires and cables.
With this in mind, new standards and protocols are created to better serve the needs of high-performance building automation systems, especially for large buildings.
Standards such as the KNX bus system promises to solve the challenges associated with the cabling and wiring works of a smart building. Another useful standard is the Power over Ethernet (PoE), which enables the transmission of electrical power and data in the same wires. This protocol can bring many benefits regarding eliminating bulky wiring works in the building automation industry.
OSI model for KNX. Screenshot used courtesy of KNX
Taking advantage of these standards is onsemi as it introduces new solutions into the market to address the growing demands of intelligent and smart buildings in the modern world.
In this article, we’ll dive into these new products and see how they have integrated the KNX and PoE standards.
KNX and PoE Standard Overviews
Before digging into onsemi’s latest announcement, let’s briefly review KNX and PoE.
Formerly known as the European installation bus (EIB), the KNX standard incorporates a bus system in which all outlet connection points, sensors, and actuators are connected to a common cable called the bus network. The bus network is a decentralized system in which devices can exchange data with every other device without passing through a central hub or distribution board. This capability allows all devices to talk to one another efficiently.
Devices that communicate with one another in this standard are grouped into three categories:
- System devices
- Sensors
- Actuators
Sensors convert the information from the real world into data packets transmitted to an actuator via the bus network. System devices include power supply, programming interface, and so on.
A KNX system regulates a device’s access to the bus network. At the same time, the data transmitted may not be directly switched on and off lights but only for address information. For example, the address information could be from a light switch sensor to control a relay to switch on the light bulbs in a room.
The KNX system is standardized across various parts of the world, including Europe and the USA. In Europe, KNX is certified via EN ISO 22510.
An overview of the PoE standards. Image used courtesy of FS
On the other hand, the PoE standard allows electrical power and IT network data to be transmitted in the same wires. This standard delivers data connection and electrical power to PoE devices via a single cable. Devices in this standard are grouped into two categories: power sourcing equipment (PSE) and powered devices (PD).
This standard finds itself in applications like wireless access points, VOIP phones, and IP cameras. However, in a building automation system, designers employ this standard to integrate power systems with wireless communication devices.
What’s more, PoE supports the internet of things (IoT), enabling a robust smart building system where devices can be connected to the internet and controlled by the data stored in the cloud.
Certified KNX and PoE Smart Home Solutions From onsemi
Recently, onsemi, targeting the development of access and control panels in building automation, has introduced two new products, NCN5140S and NCL31010, that incorporate the KNX standard and PoE protocol, respectively.
According to the NCN5140S datasheet, this device is the first system-in-package (SiP) that integrates all critical and certifiable elements of a KNX device, such as a digital KNX transceiver, a 32-bit Arm Cortex M0+, and system power DC/DC converters.
The device is stated to provide quicker development of KNX-switch-applications and is fully certified by the KNX Association. It also claims to ease hardware and software development for designers. In addition, the product supports KNX switch applications with either tactile or capacitive touch buttons. For example, it could drive up to eight buttons with RGB LED lighting for every individual button.
An example application block diagram incorporating a KNX switch using the NCN5140S. Screenshot used courtesy of onsemi
In this SiP, onsemi has also leveraged the PoE standard to manufacture the NCL31010. According to the datasheet, this device features an IEEE 802.3bt PoE−PD interface controller, a dual step−down converter, and a buck converter LED drive. Additionally, onsemi says that NCL31010 could deliver up to 90 W of power for high-power applications.
The product integrates all functions system such as detection, classification, and current limiting during the inrush phase expected in a typical PoE system.
According to the manufacturer, the PSE checks if a valid or a non−valid detection signature is present. This feature is done in the detection phase to enable the PSE to differentiate between equipment supporting PoE requesting power and equipment not supporting PoE or not requesting power.
Block diagram for the NCL31010. Screenshot used courtesy of onsemi
The PoE product finds application in visible light communication, thanks to its support for high modulation bandwidth up to 50 kHz. As 90 W is delivered, it finds application in connected LED lighting.
All in all, these solutions from onsemi aim to ease the design of smart home technology integration. It will be interesting to see what else comes down the pipeline in the future.
