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D4i and intra-luminaire DALI

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

D4i brings standardization to intra-luminaire DALI, and extends the existing DALI-2 program by adding a specific set of new features. By specifying power-supply requirements and smart-data capabilities, D4i enables intelligent, connected, future-proofed LED luminaires.

Intra-luminaire DALI refers to a small DALI network inside an individual luminaire. D4i specifications ensure that power is available for control devices—such as sensors or wireless communication devices—that are attached to or integrated into the luminaire. Meanwhile, D4i drivers inside the luminaire are able to store and report a wide range of data in a standardized way. 

>> More details on D4i specifications

>> Find out how D4i is used in intra-luminaire DALI for outdoor


DiiA members are now able to certify their D4i LED drivers in a procedure that includes independent verification of test results.

Certified products are eligible to carry the new D4i logo, a DiiA trademark which indicates interoperability. The D4i logo trademark can also be used on qualifying luminaires.

>> More details on D4i certification


D4i is aligned with the new ANSI C137.4 standard >> More details

D4i is also compatible with socketed connector systems such as NEMA/ANSI C136.41 and Zhaga Book 18.

DiiA and Zhaga are working closely together and have developed the joint Zhaga-D4i certification program for D4i luminaires that have a Zhaga socket.


D4i Specifications for Data and Power

D4i enables intra-luminaire DALI by:

  • Taking care of power-supply requirements
  • Enabling data capabilities


D4i enables intelligent luminaires by standardized the storage and reporting of data relating to the driver, light source and luminaire. The bi-directional nature of DALI enables such data to be communicated with the lighting-control network. Data stored within the driver can be used for enhanced asset tracking, as well as performance monitoring, diagnostics and energy metering.

Data specifications
DALI Part 251 – Luminaire Data
DALI Part 252 – Energy Data
DALI Part 253 – Diagnostics Data

>> More on DALI-2 Data specifications

>> Download D4i specifications from DiiA


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 for city-wide networks — an auxiliary 24V power supply is also included in the D4i specifications.

Power-supply specifications
DALI Part 250 – Integrated Bus Power Supply
DALI Part 150 AUX Power Supply

>> Download D4i specifications from DiiA

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.

Control device specification
DALI Part 351 – Luminaire-mounted Control Devices

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

D4i presentation

>> Click to view


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. 

>> Download the DiiA Requirements document "D4i Certification and Trademark Use"

News & Links

NEWS: First D4i certified LED driver added to DiiA product database (Dec 2019)

PRESS RELEASE: DiiA starts D4i certification of LED drivers (Nov 2019)

NEWS: D4i specifications updated and new Part 351 published by DiiA (October 2019)

NEWS: ANSI C137.4-2019 standard aligns with D4i specifications (October 2019)

PRESS RELEASE: D4i brings standardization to intra-luminaire DALI (May 2019)



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?
D4i certification is now available. Control devices will be added at a later date.

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 need to implement Part 207 and Parts 250-253. Part 150 is optional. In addition, the default state of the integrated bus power supply must be “on”. Products must also meet the requirements listed in "D4i Certification & Trademark Use" (download here)

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 available at a later date.

D4i specifications for intra-luminaire DALI

The example below shows a two-node, outdoor-lighting application. Power available to both nodes, and the intra-luminaire DALI bus supports socketed systems. The intelligent luminaire has sensing capabiliites and can report data stored in the LED driver to the external network via the DALI bus and the wireless link.