Feature: Lighting
The DALI Alliance is developing tests for DALI+ with Thread, which will be the first certification program for interoperable DALI+ devices
delivery can be improved by using message acknowledgement to confirm delivery. Security for DALI+ includes
authentication and encryption methods that are already part of the carrier. All Tread communication is encrypted and authenticated using IEEE 802.15.4 security mechanisms, like AES (Advanced Encryption Standard) with a 128-bit key. Only devices commissioned with the network key can exchange data, and a secret device-specific authentication is used to securely deliver the key to each device joining the network.
Figure 1: DALI+ enables lighting control over wireless and IP-based networks
Connecting DALI+ and wired systems In many systems, it may be desirable to use both DALI+ networks and existing wired DALI systems, enabled by bridges. Te DALI commands and features are the same in both cases, and the application controllers in the DALI+ network communicate via a DALI+ bridge, which enables them to talk to all types of DALI wired control systems and devices; see Figure 2. A separate approach is to use a DALI+
Figure 2: Bridges link wired and wireless DALI networks
features of DALI wired systems: for instance, they can connect to a building management system through a BACnet interface. By supporting IP-based technology,
DALI+ makes it easier for lighting control systems to communicate using existing IT systems and building automation services. For example, analytical data from lighting systems can be sent over a building’s existing network to a central computer or the cloud for analysis or archiving.
DALI+ with Thread Tread uses the User Datagram Protocol (UDP) over 6LoWPAN, a low-power wireless protocol that enables IPv6 packets to be transmitted over networks based on IEEE 802.15.4 technology. Tread is aimed at applications that only require low data rates, making it ideal as a carrier for DALI+ lighting control. Tread’s self-healing mesh network can scale up, becoming more resilient the larger it grows, providing dependable connectivity for lighting control. Reliable
application controller that can support multiple subnets; this could be any combination of DALI+ and wired DALI subnets. For example, Figure 3 shows a system with two DALI+ input devices (a sensor and a push button) connected wirelessly to a single application controller with a DALI+ interface. Te application controller also has two interfaces for wired DALI luminaire systems, which may optionally include input devices. Te application controller receives event
messages, or polls the sensors and push buttons in both the wireless and wired systems. It then makes decisions and sends commands to the bus units in the wired DALI subnets, controlling the lighting. For more complex systems, a backbone
such as Ethernet can be used to connect multiple wireless DALI+ systems together. Figure 4 shows an example of such a complex system. In this example, there are two wireless Tread networks connected with an Ethernet cable via Tread border routers. A DALI+ bridge provides connectivity to two DALI wired buses
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