D4i is a certification programme built on the DALI-2 standard. While DALI-2 ensures interoperability between lighting control devices and LED drivers, D4i adds a series of mandatory data specifications that allow drivers to communicate valuable operational information.
These data specifications are defined in:
- DALI Part 251 – Luminaire information
- DALI Part 252 – Energy reporting
- DALI Part 253 – Diagnostics and maintenance
Bright Green Connect DALI Solutions
Many of the DALI-2 LED drivers available from Bright Green Connect support DALI Parts 251, 252 and 253, enabling intelligent communication alongside reliable dimming performance.
Whether you’re specifying lighting for commercial buildings, retail environments, education, healthcare or architectural projects, choosing drivers that support these advanced DALI functions helps future-proof your lighting installation while providing valuable operational insight.
Frequently asked questions
Are DALI Parts 251, 252 and 253 mandatory?
No. These are optional extensions to the DALI standard, most commonly associated with D4i-certified LED drivers. They provide additional data and functionality beyond standard lighting control.
Do I need special controllers?
Your lighting control system or DALI application controller must support reading the information provided by Parts 251, 252 and 253 to take full advantage of these features.
What is the difference between DALI-2 and D4i?
DALI-2 standardises interoperability between lighting control devices and luminaires. D4i builds on DALI-2 by introducing additional specifications, including Parts 251, 252 and 253, that enable luminaire data, diagnostics and energy reporting.
Who benefits from these features?
These functions are particularly valuable for:
- Lighting manufacturers (OEMs)
- Building owners
- Facilities managers
- System integrators
- Smart building designers
- Electrical contractors managing large installations
DALI Part 251 focuses on storing static information about the luminaire and LED driver.
Typical information includes:
- Manufacturer details
- Product identification
- Serial number
- Manufacturing date
- Rated power
- Rated voltage
- Correlated Colour Temperature (CCT)
- Colour Rendering Index (CRI)
Because this information is permanently stored within the driver, installers and facility managers can quickly identify installed products without manually recording asset information.
Benefits
- Simplified asset management
- Easier commissioning
- Improved product traceability
- Faster maintenance
Part 252 introduces energy reporting capabilities.
Compatible LED drivers can provide information such as:
- Instantaneous power
- Total energy consumption
- Operating power
- Energy monitoring
This enables building management systems to measure energy usage more accurately and identify opportunities to improve efficiency.
For commercial buildings, retail environments and smart buildings, this provides valuable insight into lighting performance and operational costs.
Benefits
- Energy monitoring
- Sustainability reporting
- Reduced operating costs
- Improved building efficiency
Diagnostics & Maintenance
Part 253 provides operational and diagnostic information about the luminaire.
Typical data includes:
- Driver operating temperature
- Driver operating hours
- Fault information
- Performance status
- Maintenance data
This allows lighting control systems to predict maintenance requirements before failures occur, reducing downtime and simplifying planned maintenance.
Instead of waiting for luminaires to fail, maintenance teams can schedule replacements based on actual operating data.
Benefits
- Predictive maintenance
- Reduced downtime
- Improved reliability
- Lower maintenance costs
Why are parts 251, 252 and 253 important
As lighting becomes part of intelligent building infrastructure, the ability to communicate operational data is becoming just as important as controlling brightness.
Together, Parts 251, 252 and 253 allow lighting systems to become valuable sources of information, supporting:
- Smart buildings
- Energy management
- Asset tracking
- Preventative maintenance
- Building management integration
For installers, OEMs and facility managers, this means lower lifecycle costs, simplified maintenance and greater visibility across an entire lighting installation.
DALI compliant vs DALI compatible
Many DALI devices on the market today may only be DALI compatible and not DALI compliant.
DALI compatible means the manufacturer has incorporated certain elements of the DALI standard into their product, but the device has not been officially tested or certified against the standard. In many cases, these manufacturers are also not members of the DALI Alliance (DiiA).
DALI compatibility does not guarantee full DALI functionality or interoperability. Since implementation varies by manufacturer, DALI compatible products may not work reliably or correctly with fully DALI-compliant devices, depending on which parts of the standard were (or were not) followed.
Genuine DALI compliant devices carry the official DALI logo. To verify authenticity, you can search for the manufacturer on the DiiA website. All companies using the DALI logo must be DiiA members, and for DALI-2, their certified products must be listed on the site. If a product displays the logo but the manufacturer is not listed, it may only be DALI compatible which can potentially lead to partial functionality or hidden issues within your DALI system.
