DALI and Smart Lighting
The continued evolution of lighting technology focuses not only on energy conservation, but also includes control systems that combine with sophisticated sensors and IoT devices to provide true interoperability, making buildings smarter than ever before.
Interoperability, cutting-edge data capabilities and connectivity (wired and wireless) are at the heart of Digital Addressable Lighting Interface (DALI) technology.
Connected devices provide more creativity, efficiency and flexibility for lighting projects that can be controlled from a mobile phone and can respond to installations at any time.
The ease of use and versatility of wireless applications in the lighting field have had a significant impact. The use of wireless connectivity in retrofits avoids the traditional invasiveness of rewiring old buildings, although most devices still need to be powered.
In many cases, wired solutions are still the first choice, while in different cases, hybrid solutions may be required. DALI provides choices by enabling wired and wireless networks to operate in tandem, and keeps options open for the future.
However, the key to any successful system is the ability of its constituent devices to communicate effectively with each other. In lighting control, DALI is the most widely used open standardized protocol or communication language and has been used in countless applications around the world. DALI enables two-way digital communication between lighting control devices and sensors, and has the ability to address individual DALI devices, meeting the requirements of the Internet of Things.
The intelligence depth and interoperability of DALI products and the systems they create really help to achieve smart buildings with greater intelligence and functionality.
So, what is DALI? What are its advantages?
What is DALI
DALI, or Digital Addressable Lighting Interface, is an open protocol intelligent addressable emergency lighting testing solution that allows installations to be supervised, tested and monitored from a central location in accordance with the latest national standards.
It offers customers the opportunity to recover installation costs in the short term and save significant costs in the long term to cope with increasing maintenance costs, while giving customers peace of mind that emergency lighting installations fully comply with national standard testing requirements.
It also eliminates the need for maintenance engineers to perform regular physical/visual inspections of all emergency luminaires, while also eliminating the need to inspect emergency luminaires during testing. DALI allows sites to be tested during off-hours, reducing disruption to the working environment and saving end users money.
Wireless DALI has up to 128 luminaires connected to each channel, which operate over a Zigbee mesh network connected to a cloud server.
The distance of the Zigbee mesh network is significantly increased compared to wired solutions. The Zigbee network has a coverage range of up to 50m in a building environment and up to 100m in an open air environment. The system is suitable for large or small installations.
Key advantages of the new wireless DALI
Reduced capital costs：Wireless systems do not require any communication cables, additional cable fixtures, additional wire ducts, or any additional connectors, effectively reducing capital investment.
Installation Costs：The implementation of DALI wireless significantly reduces the time and costs incurred during installation, as there is no need for any additional wiring of the communication bus, connection fixtures or additional drilling.
Self-healing：DALI MESH is a self-healing network that routes back to the DALI control module regardless of the number of faulty luminaires in the network. A mesh network is far superior to a point-to-point network.
Long-term maintenance：In the long run, maintenance is easier and there is less risk of mess on site.
No rewiring required：Wireless implementation requires no rewiring in existing projects or future expansions. The system works in conjunction with wired DALI controllers, as a hybrid system or as a complete wireless solution.
DALI+ brings unparalleled flexibility to smart building lighting
For more than three decades, the DALI protocol has been the global standard for interconnected lighting systems, luminaires, and related devices. DALI’s bidirectional digital interface allows communication among lighting installations in buildings and other industrial applications, providing precise and repeatable lighting control and data collection from devices such as occupancy sensors and lux meters.
More than 300 companies have adopted the DALI protocol in their commercial lighting portfolios, ensuring a wide range of devices, products, and components available, all operating on the same interoperability standard Extending.
Wired with Wireless and IP
Originally, DALI was developed as a wired solution, running on its own transport protocol. All devices were connected to each other and to DALI control devices using a two-wire wiring system. This transport protocol meant that these wires could be used exclusively for DALI lighting purposes.
For many scenarios, a dedicated wired network can be a good solution for lighting use cases. However, there are many cases where a wireless solution will be more practical, both for installation and for daily use. Opening up the DALI protocol to run over ubiquitous IP-based transport means that networks can be shared or extended. With this in mind, the DALI Alliance developed DALI+, which combines DALI lighting control with wireless and IP-based networks. DALI+ supports IPv6 and uses the same familiar DALI protocol language, but encapsulated in IP frames.
The flexible use of wireless and IP
wireless solutions means that system architects and installers have greater flexibility when designing and setting up lighting networks. In some buildings, installing lighting system wiring is difficult or simply impossible. Considering office buildings with glass panels as "walls" opens up modern and creative lighting possibilities, such as floor luminaires. It also allows for simpler changes to the configuration and use of lighting fixtures when the use, occupancy or overall layout of the room changes later in the building's life cycle.
Transitioning to an IP-based network means that the lighting system infrastructure can be merged with the rest of the building's corporate network or VLAN. DALI packets are no longer limited to a given DALI subnet. They can traverse the entire building and connect with a building management system, or connect multiple DALI subnets to a larger DALI system, all without the use of vendor-specific protocol gateways. Shared IP networks can also host other building automation protocols and applications. This not only brings huge cost savings, because there is no need to build an infrastructure from scratch just for a single application to control the lighting system.
How DALI systems help buildings achieve intelligent optimal lighting control
When decision makers think about smart building technologies in buildings, the first thing that comes to mind is automated lighting control. Good lighting is essential for the successful functioning of any workplace and also accounts for a large portion of energy consumption.
Therefore, it is important to have intelligent and on-demand control of lighting. Among other things, this can be facilitated by the use of highly accurate multi-sensors, allowing building managers to control artificial light based on occupancy and brightness levels.
DALI-based lighting control systems allow this to be achieved accurately, allowing managers to first plan the best solution for the requirements of the smart building. Typically, engineers create CAD drawings based on the definition of the lighting group in close consultation with the building facility manager.
Commissioning is a complex phase. During this phase, the system and the build can be adjusted, and the necessary rules and user authorizations are clearly defined. This ensures that building managers have accurate access to the most relevant parts of the system for their needs.
Measuring Brightness
For the best functionality of smart systems, the measured brightness values need to be extremely accurate. This is achieved by finding the best mounting position on the ceiling, where the measurement is affected as little as possible by external factors such as reflections, direct sunlight or other light sources. Brightness values should be measured in the darkest part of the room, which can vary from room to room depending on its location in the building. However, the detection range of the device must of course ensure adequate coverage of the range of movement of the room's occupants.
For optimal lighting control, the difference between the brightness of the desk and the ceiling must be balanced in the logic of the multi-sensor. Therefore, the actual values measured by the light sensors on the ceiling are not used for control to supplement the natural light with the right amount of artificial light. Instead, the so-called reflectance coefficient is used as the ratio of the light between the work surface and the ceiling.
For DALI-based systems, the weighting of the reflectance values is set individually according to the environmental variables at the respective place of use.
Employee access
Via a username and password, employees gain access to the areas in which they can influence lighting control. They can log in via a browser and control the lights in a room or office. Via a user-friendly interface, scenes can be selected, switched and dimmed.
For example, in a specific meeting room or boardroom, employees can also control the lights via their smartphone. These scenes are stored in the system and can be called up for different meeting scenarios with just a click.
System connectivity
Via a BACnet router, it is easy to connect the system to a higher-level building management system or to existing parallel systems in other departments, such as heating, ventilation, blind control or access control. Each router provides up to 712 nodes via BACnet/IP, with the help of which lighting values, presence and status information can be read. Multi-state objects allow different lighting control commands to be routed from higher-level software to the DALI system.
In this way, for example, a lighting control system can be overridden from a BACnet-based control center. Hidden features such as remote maintenance options or software updates of control devices via the DALI bus help to increase the operational reliability of DALI-based systems. A quick system overview and automatic error notifications help with maintenance. Key data such as the lighting times of individual luminaires or the energy consumption of the system can be viewed transparently at any time. System administrators can monitor, configure and maintain the system via a PC or mobile device. What a user-friendly and environmentally friendly lighting this is.
To make buildings even more "intelligent", high-tech wall sensors can also be added that measure air quality and humidity based on the level of volatile organic compounds (VOC) or carbon dioxide (CO2) in the air and also act as temperature controllers.
VOCs are released into the indoor air through natural emissions from the human body, mainly through ventilation systems. High concentrations of CO2 can cause individual inattention, headaches or untidiness, which is a problem in the workplace or office.
With the help of built-in LED traffic lights (green, yellow and red), these wall sensors warn through color changes and also emit additional acoustic signals if the indoor air reaches critical values. This means that if the air quality is poor (red), you can turn on the air conditioner or open the windows to improve the air quality in the room.
The Future of Architectural Lighting
DALI has been the first choice for professional lighting equipment around the world and has been meeting the needs of many buildings for decades, especially new demands in energy efficiency, integration, compatibility and flexibility in installation, maintenance, monitoring and use, which has also led to a strong expansion of the proven DALI protocol. Smart buildings are the future direction of development, and DALI is the best choice for wireless test systems.