LED Technology
How DALI enables flexible, reliable wireless lighting control
Adding wireless capabilities to a lighting control system is an attractive option: it can make a system more flexible and scalable, as well as quicker and easier to install. While wireless lighting control products have been available for some years, it’s arguable that their adoption has been held back by worries about interoperability. A globally used, fully-featured standard is needed to ensure everything works together reliably and efficiently.
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or wired lighting control, the Digital Addressable Lighting Interface (DALI) is an open standardized protocol that has been widely adopted and proven. Based on the open global standard IEC62386, DALI is managed by the DALI Alliance. This is a consortium of lighting companies with more than 380 members globally, which operates certification programs to ensure cross-vendor interoperability. Typically, DALI uses a dedicated two-wire bus for bi-directional communications between lighting control devices and sensors. Instead, DALI now offers two options for wireless implementation, as well as the flexibility of combining wired and wireless networks: DALI+ enables devices to communicate using existing DALI commands, carried over a wireless or internet protocol (IP)-based medium
Wireless to DALI gateways enable existing DALI wired products to be used in a non- DALI wireless system
Wireless lighting systems are typically organised in a mesh configuration, where each device (or node) is connected to multiple other nodes. This increases reliability, as there is no single point of failure, and control messages are automatically re-routed if one node fails. It might seem simpler just to implement the entire lighting control network using an alternative wireless protocol throughout. However, DALI was developed specifically for lighting and has tailored lighting- control features, as well as the availability of luminaire, energy and diagnostics data. Other protocols cannot offer the same comprehensive set of standardised, lighting- specific features, or access to a huge range of existing DALI-certified products.
The wireless standard: DALI+ DALI+ builds on the proven DALI lighting- control features in wired systems and offers access to the same rich set of data from control gear, luminaires and sensors. All DALI
44 February 2024 Components in Electronics
www.cieonline.co.uk
Figure 1: Gateway (GW) between a non-DALI wireless ecosystem (Bluetooth mesh or Zigbee) and a DALI system.
control gear and control devices from IEC 62386 can be implemented in DALI+, including LED drivers, colour-controllable drivers, emergency drivers, application controllers, push buttons, and sensors.
Initially, DALI+ supports Thread, which is an IP-based, low-power, wireless mesh networking protocol. Security is provided by the authentication and encryption methods that are already part of Thread, and the lighting system can take advantage of Thread features such as
self-healing and automatic configuration. To increase flexibility, other Thread devices can be used in the same Thread network as the DALI+ devices, enabling designers to add non- DALI devices such as sensors or door locks. The use of an IP-based carrier such as Thread for DALI+ also enables integration of the lighting system with other functions via a building’s IT infrastructure. DALI+ with Thread supports IPv6 addressing, so the number of devices in a DALI+ system is virtually unlimited.
Wireless-to-DALI gateways The second option for wireless implementation is to use wireless-to-DALI gateways, which enable existing wired DALI devices to be used in a non-DALI wireless ecosystem. The gateways translate commands from the wireless side to enable control and querying of the DALI devices by the wireless ecosystem, as if they were part of the wireless network.
Figure 1 shows how a gateway participates Figure 2:
Combining wired and wireless control with gateways.
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