Simon Blazey, solutions sales manager, Tridonic UK discusses how it is possible to create smart lighting solutions with freely selectable components, paving the way for the Internet of Things.

The DiiA is extending the DALI-2 certification programme for smart LED drivers to include the new D4i standard. The standard defines certification conditions for the simple integration of sensors and communication modules in LED luminaires. It is based on a DALI power supply within the luminaire via which the sensors or communication modules can be integrated in the luminaire and powered without the need for an additional DALI line.

Interoperable technologies and common standards are absolutely essential for the future development of smart lighting. Based on experience with the DALI-2 standard, DiiA and Zhaga together with its members have developed extended certification requirements that greatly simplify the integration of sensors and communication modules in luminaires and, at the same time, pave the way for the Internet of Things. Components that meet all these conditions receive the D4i logo, which stands for the simple integration of additional control components and for reliable interoperability.

At the heart of the new standard is an integrated DALI power supply that brings the tried and trusted DALI standard directly into the luminaire. This power supply acts as an interface between an LED driver and a sensor or between an LED driver and a communication module. The LED driver supplies the connected sensor or another control device with power and can receive and process DALI control signals via the DALI bus in the luminaire. There is then no need for an additional controller for the sensor. In this way, sensor-controlled lighting solutions can be implemented much more easily than before because no additional DALI lines have to be laid outside the luminaire.

Flexible luminaire design

Luminaire manufacturers have a free choice of components because the D4i logo guarantees smooth interoperability between components from different suppliers. The wiring inside the luminaire is also greatly simplified as the usual controller for the sensor is no longer needed so there is one fewer component to be integrated in the luminaire. Luminaire designers have much greater freedom because luminaires can be made smaller than ever before. The integrated DALI power supply allows for simpler, non-proprietary sensor operation so that the light from each luminaire can be controlled according to factors such as presence/absence and the amount of ambient light.

Access to the Internet of Things

If the sensor is also equipped with a wireless interface, such as WLAN, Bluetooth or Zigbee, or if a radio-based communication module is connected, the luminaires can be interconnected without the need for additional cables and integrated in higher-level management systems or IP systems.

What’s behind the D4i logo?

The extended DALI-2 certification conditions for the DALI bus within the luminaire define the power supply (DALI Part 250), data storage and data access (DALI Part 251), performance and energy consumption data (DALI Part 252) and operating data (DALI Part 253). Power is supplied directly via the internal DALI bus or via an additional 24V supply if the supply via the bus is not sufficient, for example for communication modules in outdoor areas.

DALI Part 251 describes how luminaire manufacturers can use the new database to store information such as the Global Trade Item Number (GTIN) of the luminaire, the date of manufacture and luminaire parameters such as rated output, color temperature, CRI value and lumen values. The DALI luminaire specifications define the location, type and format of the data in the database of the control device, the conditions for accessing the data, and protective functions.

DALI Part 252 defines which performance and energy consumption data a DALI-2 control device can provide. In the case of networked lighting solutions, the data can be used to derive measures to control the lighting on the basis of demand and to reduce energy consumption.

DALI Part 253 deals with the data of the control device, the LED light source and the LED luminaire. For control devices and luminaires, for example, the number of starts, the total operating time or times and output control in the event of thermal overloads are recorded and made available. Design parameters based on the life of the luminaire can also be recorded and made available. This data forms the basis for predictive maintenance and repair, and helps to reduce maintenance and repair costs.

If a DALI-2 control device complies with all the specifications it will be granted the D4i logo from the DiiA. The logo confirms the interoperability of the components and paves the way for the Internet of Things.