2022
September
22

DALI+ OVER THREAD BRINGS UNPARALLELED FLEXIBILITY TO LIGHTING IN SMART BUILDINGS

By Jorg Kennis, Thread Smart Building Marketing, Neovate Innovation Partners

For over three decades, the DALI protocol has been the worldwide standard for interconnecting lighting systems, luminaires, and related devices. DALI’s bi-directional digital interface allows for communication in lighting installations in buildings and other industrial applications, making it possible to offer precise and repeatable lighting control and gathering data from such devices as occupancy sensors and light-level meters.

Over 300 companies have adopted the DALI protocol in their commercial lighting portfolios, making sure that there is an enormous number of devices, products, and components available, all working based on the same interoperability standards.

Originally, DALI was developed as a wired solution, running on its own transport protocol. All devices use a two-wire cabling system to connect to each other and to the DALI control equipment. This transport protocol means that these wires can be used exclusively for DALI lighting purposes.

For many scenarios, a dedicated wired network addresses the lighting use case well. However, there are a considerable number of situations where a wireless solution would be more practical, both for installation and in daily usage. And opening the DALI protocol to run on ubiquitous IP-based transports means that networks could be shared or expanded. With this in mind, the DALI Alliance developed DALI+ which combines DALI lighting control with wireless and IP-based networking. [TW1]

DALI+ supports IPv6, and uses the same familiar DALI protocol language, but packed into IP frames. The DALI Alliance chose Thread as their first [TW2] wireless carrier for DALI+, offering wireless connectivity for all types of DALI devices.

A wireless solution means that the system architects and installers have much more flexibility when designing and setting up the lighting network. In some buildings it’s hard to install cabling for the lighting system, or downright impossible. Think of office buildings with glass panels as “walls”. And it opens modern and creative lighting possibilities, such as ground based fixtures. It also allows for much easier ways to change the configuration and usage of a lighting luminaire when the purposes, occupancy or general layout of a room changes later in the building’s life cycle.

Making the transition to IP-based networks means that the infrastructure of the lighting system can merge [TW3] with the rest of the building’s corporate network or VLAN. DALI data packets are no longer limited to a given DALI subnet. They can travel across the entire building and interface with building management systems or connect multiple DALI subnets into one larger DALI system, all without the use of vendor specific protocol gateways. The shared IP network may also host other building automation protocols and applications. This not only brings great cost-savings as there is no need to build an infrastructure from the ground up just for the single application of controlling the lighting system.

Unlike wireless lighting solutions that are based on other protocols, DALI+ on IP and Thread clearly separates between the highly specialised lighting application layer (DALI) and the common IP network including its physical transport technology. With legacy wireless protocols, it is often impossible for devices to co-exist in the same network, as there is no convergence layer between the physical transport and the application protocol. DALI+, on the other hand, will seamlessly integrate with other DALI+ with Thread devices from any vendor and can share the IP network with other IP-based protocols that serve other building automation domains, like Matter, KNX or OCF. This opens more simplified means of interaction with other parts of the building, and new ways of integration with software and services.

DALI+ on IP-based networks like Thread offer many of the advantages that make DALI the ubiquitous choice for professional lighting installations. Think of the standardised dimming curve, which makes sure that all the lights are dimmed to the exact same levels, independent of lighting type, model or brand. Or well defined colour control models, which precisely define how colours are set for all lights and how fading between colours happens, unlike other technologies (that often found their origin in the consumer domain) that simply broadcast values and have no verification of light output and fade timing as part of their verification program. DALI+ integrates with wired DALI-2 installations, and offers full compatibility and transparency when setting up and using mixed installations of wired and wireless DALI products.

Using DALI+ on a wireless Thread network means that the lighting system can use all the benefits that Thread brings.This includes the self-healing and automatically configuring shared mesh capability that is used among devices of various types and applications. As any powered Thread device, a DALI+ luminaire can connect to any other Thread device nearby (including for example HVAC systems), thereby even further increasing the reliability and reach of the network. Thread’s low-power optimization also means that any of these mesh capable devices can connect to low-power end devices like sensors that can run on batteries for many years at length. And of course the DALI+ devices on a Thread network can leverage Thread’s industrial grade encryption and security features.

The Future of Lighting in Buildings

DALI has always been the world’s go-to choice for professional lighting equipment, and it has served the needs of many buildings well for decades. New demands in terms of energy efficiency, integration, compatibility and flexibility in installation, maintenance, monitoring and usage have led to a powerful extension of the proven DALI protocol. IP-based DALI+ on Thread ticks all the boxes of demanding lighting applications in buildings, factories and other commercial and industrial applications.

If you want to see DALI+ with Thread in action, make sure to visit the upcoming Light+Building expo in Frankfurt Germany, from October 2 to October 6, where many companies will be showcasing their latest products and implementations.

For more information about DALI+ with Thread, you may also refer to the DALI Alliance website at https://www.dali-alliance.org/daliplus.