Things You Need To Know About DALI D4i, DT6, DT8

The IoT (Internet of Things) era's DALI protocol is defined by the new DiiA specifications known as D4i.

An expert in DALI would contend that D4i would be ideal for intra-luminaire DALI.

Should we anticipate this to be true? What what does an intra-luminaire mean?

Learn more about D4i's differences from earlier DALI iterations below.

1. D4i  

1.1 D4i Overview

A DALI-2 function extension is called D4i. The DALI-2 certification has been extended by this. It seeks to improve support for data-related services such as lighting assets, energy, and operation based on intelligent IoT bulbs and DALI-2 lighting control. data gathering and analysis, including diagnosis.

The Internet of Things is supported by the D4i standard for DALI (IoT).

The DALI-2 capability of the intelligent D4i LED control device (LED driver power supply) in the D4i lamps allows it to report lamp asset data, energy data, and diagnostic data in standard formats. It is simpler to install the sensor and communication equipment on the lamps due to the controller's installation interface requirements.

The perfect Internet of Things nodes are intelligent D4i bulbs. D4i sensors and control gears can gather a variety of data to offer information for a variety of functions, including asset management, predictive maintenance, and performance monitoring. Through a D4i controller with wireless communication capabilities, these data can share and connect with a network outside of the computer.

Control gear/LED drivers and control devices are both included in the D4i certification programme, which is an expansion of the DALI-2 certification scheme.

The extension function in D4i is primarily as follows in order to enable the data support of intelligent lighting in the Internet of Things era:

• Monitoring of Lighting Assets; 

• Lighting Assets Monitoring; 

• Lighting Debugging Data Interaction; 

• DC Auxiliary Power Supply; 

• Power Supply for the Bus

As of October 2019, ANSI has created ANSI C137.4, which includes the D4i standard for DALI and the American National Standard for Lighting Systems-Digital Interface with Auxiliary Power.

Recently added standards for other D4i as well as the bus supply (DALI Part 250), the auxiliary supply (DALI Part 150), and the lighting information (DALI Part 251). This implies that D4i, in addition to becoming the widely accepted standard in Europe, also becomes so in North America for smart lighting. In addition, D4i can be used with socket-type connectors that enable hot swapping and intelligent lighting, as defined by Zhaga Books 18 and 20 and Nema/ANSI C136.41.

1.2 D4i LED control gear

The LED control equipment must provide DALI data support capabilities, including part 251, 252, and 253, in order to be D4i certified.

• DALI Part 251: Data on lighting fixtures

• DALI Part 252: Data on energy

• DALI Part 253: Data debugging for the bus supply and, optionally, the assistance auxiliary DC power supply

A DALI integrated bus power supply is the DALI-250 (mandatory)

Auxiliary power supply DALI-150 (optional, LED driver for outdoor or high-power industrial)

The D4i LED driver has a built-in DALI bus power supply that can power any connected DALI control device. The ability to incorporate DALI sensors or other control devices that can only be powered via the DALI bus in applications involving smart lighting. An additional 24V power source is needed for control devices with high power requirements, such as wireless communication control equipment for road lighting. Either a separate piece of power equipment can supply it, or it can be included within the LED control device.

1.3 D4i control apparatus

The DALI 351 standard applies to control equipment that can be mounted inside lamps or attached to lamps as well as D4i control devices. The D4i device needs a DALI bus or an additional power source.

In addition to outlining the particular specifications for the device's power consumption, DALI Part 351 sets the standards for four separate categories of control devices (A through D). When there are numerous control devices, it specifies how to decide which control device has priority. Applications of Type A-D include wireless network lighting controllers, light sensors, motion sensors, and timers for both indoor and outdoor use.

2.Common device type DT (DT6, DT8)

When discussing DALI control, we frequently hear DT6 or DT8 mentioned. What do they imply?

DALI can communicate with bulbs in both directions. You may check to see if the lamps are working properly and the brightness of the lighting. The DALI protocol has been expanded multiple times since its beginnings, and each new device has been assigned a new number (device type X = DTX). Emergency light (DT1), LED (DT6), and RGB/tunable white light control are the most recent noteworthy changes (DT8). The IEC 62386 standard's components are illustrated in the image below. The company's control solutions include DALI DT8 and DALI DT6. The first is for color-controllable luminaires, while the second specifies the size of the control gears.

But how are their respective systems designed to handle their individual controls?

2.1DT6-LED Driver or control gear

The characteristics of the control gear, a device type 6 device, are described in Part 207. The Device Type 6 is referred to as the DT6 for convenience in the nomenclature, which stands for DALI Dimmable LED DRIVER. It is clear from the DALI standard organisational structure that the three standard requirements of Parts 101, 102, and 207 must be met by the control devices of DT6. The market's most popular DALI product category right now is the DT6. In both indoor and outdoor lighting control systems, LED drivers with constant current and voltage are the primary product forms.

2.2 DT8-Color Control Device

Device Type 8 is known by the initials DT8 (color control device). However, unlike the Device Type 6 (lamp control device), the Device Type 8 (switch control device) does not appear to match to a specific product, and vice versa. Only that its definition object is a control device that can modify the output colour was specified in part 209 of the document. It might be the control device for an LED lamp or it might be the control device for another kind of light source bulb. The control device that supports DT8 is typically the LED lamp control device that supports light output colour, thanks to the advancements in lighting technology to this day. The DALI tunable white LED driver or multiple output LED driver is also referred to as DT8. The three standard specifications—Part 101, Part 102, and Part 209—must be met by DT8 control gears from the standpoint of actual application requirements.

Using the two DT6 devices, connect the CW (cold white) and WW (warm white) two different colour temperature sources of different colour temperatures. Then, adjust the two-way control device output level through the master to change the colour temperature and brightness. This method is generally used before the standard formulation of the DT8 if the light colour needs to be adjusted in the application.

More DT6 devices are required to connect various coloured light sources in order to change the RGB colour temperature. Only DT6 can, according to the adjustment's results, also accomplish the goal of modifying the lamp's colour temperature or RGB colour. However, this approach also has a clear drawback:

• The bus must have two or more control devices or addresses. 

• The master controllers are used to change the RGB colour or colour temperature characteristics, making it challenging to ensure consistency and compatibility.

• Using numerous independent control devices to make the system more expensive and complex.

Additionally, greater installation space is needed. The characteristics of the colour adjustment are integrated into the internal to conform to the DT8 standard control device and only one address is occupied, which can effectively solve the aforementioned issues while making it simpler to use. Since the new device types DT24 (Tc) and DT25 (xy) can be integrated to replace it, the content of the DT6 and DT8 specifications will be drastically reduced until the protocol version is upgraded until it is progressively abolished.

2.3 The difference between DALI DT8 and DALI DT6

Let us summarize the difference between these two in fewer characters:

2.4 Conclusion

We can safely assert that DT8 saves time, manpower, space, complexity, and money because: 

• A DALI DT8 fixture uses a single DALI short address to control two or more outputs on a single DALI DT8 LED driver. As a result, the number of such addresses and LED drivers required for color-changing control is significantly reduced. 

• DALI DT8 requires only one address for tunable white control, whereas DALI DT6 requires two addresses.