DALI 2: the new version of the standard

1.  Overview

The DALI protocol was first drafted in the late 1990’s and has undergone revisions as it evolved. The key tenet of DALI is interoperability, and DALI 2 helps fill the gaps in the original standard. DALI 2 adds new features, introduces control devices and sets the basis for future incorporation of input devices, whilst maintaining backwards compatibility.

 

2.  Improvements and additions

2.1 Parts 101 & 102 restructured

There are many improvements in the new version including several new commands and features. For the first time, IEC 62386 includes standardisation of control devices. To accommodate this, changes were necessary in parts 101 and 102 to ensure there would be a clean split between system requirements in part 101 and control gear requirements in part 102. Part 103 of the standard introduces general requirements for control devices.

 

 

Revision of part 101: General requirements - System
  • Bus timing requirements are now collected together (from part 102 and a previous draft of part 103), allowing for control devices, including single-masters and multi-masters
  • Insulation and earthing requirements are changed/added
  • Operation through power interruptions is now defined, including short interruptions and long interruptions
  • Bus power supplies and advanced bus power supplies have defined start-up timing
  • Signal voltage rating: now 10V minimum for transmitter high level voltage
  • Except for devices containing a bus power supply, the interface must be polarity insensitive
  • Device marking requirements have changed
  • Bus powered units are defined, allowing bus powered control gear and control devices
  • Signal rise/fall times and signal timing improved and clarified
  • 24-bit frames defined, and 20 & 32 bit frames reserved
  • Multi-master timing defined
  • Multiple logical units are now allowed within a single bus unit
  • Part 101 now includes test sequences
Revision of part 102: Control gear

  • Fading rules/timing clarified
  • Variable lastActiveLevel added. Command GO TO LAST ACTIVE LEVEL added
  • Extended fade time for fades up to 16 minutes
  • Operating modes allow manufacturer specific operation, and a standardised way to return to normal operation
  • New WRITE MEMORY LOCATION - NO REPLY command, and RESET MEMORY BANK
  • SAVE PERSISTENT VARIABLES command has been added
  • QUERY LIGHT SOURCE TYPE added
  • PING command defined, but to be ignored by control gear (allows detection of single masters)
  • Many additions and improvements to the test sequences

 

 

New part 103: Control devices

  • Single masters and multi-masters allowed
  • Input devices defined
  • Application controllers defined
  • 24-bit frame format defined
  • Timing described in part 101
  • Addressing modes defined (64 short addresses, 32 group addresses, instance addressing, instance groups & feature type addressing)
  • Events defined
  • Manufacturer specific modes defined
  • Memory banks defined
  • Commands to enable and disable application controllers
  • Quiescent mode defined, where control devices shall not transmit any forward frames
  • Event priorities defined

 

 

2.2 Control device standardisation - Application controllers & input devices

Publication of part 103, General requirements - control devices, also enables further standardisation on specific parts for control devices. The roadmap outlines the first standardisation of input devices – a type of control device that provides information - an input - to the system. Another type of control device known as an application controller, can use the information provided by input devices and other sources to allow them to make decisions and send commands to control gear.

Application controllers can operate as single masters or multi-masters. The bus communication requirements for both types are described in part 103. Input devices are multi-masters, but are also capable of operating in a mode where they are simply polled by application controllers.

Highlights from part 103 can be seen in the table above.

 

2.3 Backwards compatibility

The changes introduced in DALI 2 are designed to improve interoperability, including situations such as replacing existing control gear with DALI 2 compliant control gear, or using DALI 2 compliant control devices with DALI 1 control gear. This backwards compatibility is described in the FAQ.

 

3.  Status & roadmap

3.1 Current publications

New editions of existing parts of the standard – version 2 of parts 101 (system) and 102 (control gear) were published in November 2014, at the same time as the new part 103, bringing in standardisation of control devices for the first time. Due to copyright, the standard cannot be shared but can be purchased from national standards organisations in most countries, or from the IEC webstore.

3.2.    Planned publications

Several new parts are currently being written. These include input devices, including parts for push-buttons and digital inputs, rotaries and sliders, presence detectors, light sensors and feedback. New parts for control gear are also being written, including features such as load shedding/demand response, lamp and gear thermal information, and power measurement.

Experts from the lighting industry make up the project team responsible for authoring, reviewing and editing the IEC 62386 standards. These experts come from various companies worldwide. To nominate an expert to join this project team, please contact the IEC national committee representative for your region.

4.  Compliance testing & licensing

4.1. DALI compliance & trademark use

To ensure a high level of interoperability of products designed to IEC 62386, DALI sets the requirements for compliance and use of the trademarks. See the following pages:

DALI Trademark Usage

DALI Testing

4.2. DALI 2 compliance

With DALI 2, a new licensing process is being introduced. This provides some additional requirements:

  • Test results shall be provided to DALI for approval. This will initially be a manual process, but later will be automated by use of a licence web-server.
  • Product licences shall be purchased before the product can be approved.
  • Approved products are publically listed in a DALI 2 product database. Provided the product entry in this database is visible to the public, the use of the DALI 2 trademark on the product is granted.

NOTE: Until the DALI 2 licensing process starts, use of the DALI 2 trademark is strictly not allowed.

An overview of this process is shown below: