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D4i and intra-luminaire DALI

UPDATE - November 2019

Latest versions of the D4i specifications—including the NEW Part 351can be downloaded here.

>> View the news item (October 2019)

DiiA expects that D4i certification of LED drivers will start in November 2019. Please check here for further updates.

Further updates are being made to the information below.

D4i – A new logo and certification program for intra-luminaire DALI

D4i extends the existing DALI-2 certification program with additional features and functions, creating new possibilities for DALI in the IoT world.

>> Download the D4i press release (May 2019)

D4i certification will be available for DALI-2 products that have a specific set of features required for intra-luminaire DALI. These features relate to power-supply requirements, as well as data for enhanced asset tracking & performance monitoring, diagnostics and energy metering.

D4i-certified products—including control gear for LEDs (drivers), as well as control devices such as sensors and wireless communication devices—will be eligible to carry the new D4i logo, which is a DiiA Trademark.

Certification requirements

To qualify for D4i certification, products must comply with the DiiA Requirements document "D4i Certification and Trademark Use". 

Commencing in November 2019, D4i certification will be available for LED drivers and stand-alone AUX power supplies.

The D4i logo trademark can also be used on qualifying luminaires. 

Certification of control devices will follow at a later date. 

>> More details on D4i certification

D4i Specifications for Data and Power

D4i enables intra-luminaire DALI by:

  • Taking care of power-supply requirements
  • Enabling DALI-2 Smart Data capabilities


D4i standardizes the way in which data is stored and accessed in DALI-2 LED drivers. This enables smart luminaires that are capable of participating in the IoT. The relevant DiiA specifications are Parts 251-253, which cover the storage and retrieval of data related to asset management, energy usage, diagnostics and maintenance.

  DiiA Specifications

DALI-2 Smart Data specifications
(Define how data
is stored, accessed
and reported)

DALI Part 251 – Memory Bank 1 Extension
- Covers luminaire-related data for asset management
DALI Part 252 – Energy Reporting
DALI Part 253 – Diagnostics & Maintenance


D4i also defines how a driver with an integrated DALI bus power supply can provide power to a connected DALI device on the bus. Within a single luminaire, this greatly simplifies the incorporation of DALI sensors or other control devices that are solely powered from the DALI bus. For control devices with higher power requirements, such as wireless communication devices, an auxiliary 24V power supply is also included in the D4i specifications.

  DiiA Specifications
DALI Part 250 – Integrated Bus Power Supply
DALI Part 150 AUX Power Supply


NEW - DALI Part 351 for control devices

DALI Part 351 is a new specification for control devices that are used in or on, or are attached to, a luminaire. Control devices can be bus-powered or externally powered (e.g. by an AUX supply).

The specification includes requirements for power consumption, a mechanism to arbitrate between multiple application controllers, and a memory bank definition for multi-master devices.

The specification includes several device types. These will be explained in a forthcoming Application Note, that will also give some example use-cases.

  DiiA Specification
Control device
DALI Part 351 – Luminaire-mounted Control Devices

>> Download Part 351 (version 1.0, October 2019)

Data specifications (DALI Parts 251-253)

DALI Parts 251-253 standardize the storage and retrieval of data in the DALI memory banks of a DALI-2 driver.

The DALI Part 251 specification describes how to store luminaire-specific information that has no impact on the functionality of the driver. For example, a manufacturer can encode data about the luminaire – such as part number, or nominal light output – in the factory. When the luminaire is installed, the data is readily available to the lighting-control network. A utility company or lighting-installation owner could use this capability to monitor and manage their lighting assets accurately and efficiently.

The DALI Part 252 specification standardizes the storage and reporting of data relating to the driver’s usage of energy and power.

DALI Part 253 focuses on diagnostics and maintenance, and covers a wide variety of data related to the driver, light source and luminaire.

>> Download the DiiA specifications

>> View the Case Study: "Intra-luminaire DALI enables Georgia Power to fast-track smart lighting project"


The D4i logo and D4i wordmark are trademarks in various countries in the exclusive use of DiiA. Use of these trademarks is restricted to DiiA members only. 


What is intra-luminaire DALI?
As the name suggests, intra-luminaire DALI refers to a DALI bus within an individual luminaire, connecting the LED driver(s) with any DALI-2 control devices. 

What is the difference between DALI-2 and D4i?
For LED drivers and control devices, D4i is an extension of DALI-2. D4i products are DALI-2 products that have a specific set of features. All D4i-certified drivers and control devices are also DALI-2 certified. Such products can optionally carry either the D4i logo or the DALI-2 logo, or both.

When will D4i certification be available?
DiiA expects that D4i certification will be available in the fourth quarter of 2019.

What data can be read out from a D4i driver?
Data related to asset management, energy usage, diagnostics and maintenance can be stored in and retrieved from the driver. Details can be found in the DiiA specifications—Parts 251 to 253.

What are the necessary criteria to achieve D4i certification?
LED drivers will need to implement Part 207 and Parts 250-253. In addition, the default state of the integrated bus power supply must be “on”.

Can the D4i logo be used on sensors?
Yes, the new D4i specification DALI Part 351 defines the D4i requirements for sensors and other control devices. D4i certification will be availabe at a later date.

D4i specifications for intra-luminaire DALI