Digital Addressable Lighting Interface

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Digital Addressable Lighting Interface ( DALI ) is a protocol used in building automation to control lighting control devices such as B. Switching power supplies ("electronic transformers"), electronic ballasts (EVG) or electronic power dimmers .

General

DALI components

Each operating device that has a DALI interface can be individually controlled via DALI short addresses and the intensity can be changed. Through a bidirectional data exchange, a DALI control device or a DALI gateway can query the status of light sources or operating devices of a luminaire or set their status. Each operating device on a DALI line can be assigned up to 16 groups to enable synchronous control of the operating devices. In addition, up to 16 presets (= predefined intensity setting values) can be saved for each operating device and called up as required. DALI can be operated as an "island system" with a maximum of 64 operating devices or as a subsystem via DALI gateways in modern building automation systems. In principle, DALI has become the successor to the still dominant 1–10 V standard (electronic ballasts with an analog 1 to 10 V interface; see Appendix E [control interface for controllable operating devices] of DIN EN 60929 (VDE 0712-23) : AC and / or DC supplied electronic control gear for tubular fluorescent lamps - requirements for the mode of operation) established. DALI is also considered the successor to the Digital Serial Interface (DSI). The main differences are, on the one hand, that each DALI operating device can have individually different intensity setting values, while with 1–10 V or DSI all operating devices always have the same intensity setting value. On the other hand, with 1–10 V or DSI, only a unidirectional flow of information (from the controller to the control gear) is possible.

DALI uses a serial, asynchronous data protocol with a transmission rate of 1200 bit / s at a voltage level of 16 V. The control line is galvanically isolated and polarity-free (reverse polarity protected). The standard does not specify the plugs, terminals and cables to be used. The lines can be laid in almost any topology , i.e. star, line or tree structures. However, a ring-shaped connection of components must be avoided. The cable length between two system participants is limited to a maximum of 300 meters (depending on the cable cross-section). No terminating resistors are required at the end of a line.

DALI offers the option of adopting a certain "system failure level" (so-called system failure level) in the event that the open circuit voltage of 16 V fails and communication with the operating devices is no longer possible.

standardization

The IEC sub-committee SC 34C is working on the IEC 62386 series of standards "Digitally addressable interface for lighting".

IEC 62386-1xx Parts 1xx: General requirements
IEC 62386-101: 2009-06 Part 101: System
IEC 62386-102: 2009-06 Part 102: Control gear
IEC 62386-103: 2016-10 Part 103: input devices
IEC 62386-2xx Parts 2xx: Special requirements for control gear
IEC 62386-201: 2009-06 Part 201: fluorescent lamps (device type 0)
IEC 62386-202: 2009-06 Part 202: Emergency lighting with single battery (device type 1)
IEC 62386-203: 2009-06 Part 203: Discharge lamps (except fluorescent lamps) (device type 2)
IEC 62386-204: 2009-06 Part 204: Low-voltage halogen lamps (device type 3)
IEC 62386-205: 2009-06 Part 205: Supply voltage regulator for incandescent lamps (device type 4)
IEC 62386-206: 2009-06 Part 206: Conversion of the digital signal into a direct voltage (device type 5)
IEC 62386-207: 2009-06 Part 207: Special requirements for control gear - LED modules (device type 6)
IEC 62386-208: 2009-06 Part 208: Switching function (device type 7)
IEC 62386-209: 2011-06 Part 209: Color / color temperature control (device type 8)
IEC 62386-210: 2011-04 Part 210: Sequencer (device type 9)

In addition, the DALI is standardized by the National Electrical Manufacturers Association .

properties

The planning and commissioning of DALI systems requires careful consideration. There are important boundary conditions to be observed, which are derived directly from IEC 62386:

  • A maximum of 64 actuators and / or a maximum of 16 groups are permitted per DALI bus.
  • The maximum current consumption of a DALI circuit is 250 mA.
  • The current consumption per DALI actuator (one DALI load) is a maximum of 2 mA.
  • The maximum voltage drop between the transmitter and the actuator must not exceed 2 V.

Further boundary conditions arise indirectly from the standard:

  • The cable length is 300 m (when using 1.5 mm² conductors).

When using the maximum cable length, it is not advisable to lay DALI in combination with the mains cable.

  • Not all types of laying of the bus are allowed, ring shape should be avoided entirely.

The DALI components are usually supplied with energy via a separate mains supply.

The isolation of the digital interface corresponds to the requirements of a basic isolation ; the test is carried out in accordance with the IEC 60928 standard. Thus, SELV (Safety Extra Low Voltage) is not guaranteed. The connection lines between the digital interface and the mains supply lines (e.g. 230 V) can be laid if the insulation conditions (double insulation) are observed. The two "free" lines of a 5x1.5 mm² NYM line are therefore often used for the control lines (together with the remaining wires for external conductors, neutral and protective conductors).

Parameterization of the actuators

The actuators (usually the operating devices of the lights) can be parameterized. The following parameters can be set:

  • Lowest dimming value (min. Level)
  • Highest dimming value (max. Level)
  • Dimming value when switching on the power supply (switch-on level)
  • Dimming value in the event of system failure (system failure level)
  • Dimming rate or step speed (fade rate)
  • Dimming time (fade time)
  • DALI address
  • Group assignment
  • Scene values

Dimming rate and dimming time

These parameters allow the light output to change gently from one dimming value to another. The setting is made via one byte. A defined dimming rate and dimming time are assigned to each byte value. The following table summarizes the setting values

Byte value

(decimal)

Byte value

(hexadecimal)

Dimming time

in s

Dimming rate

in steps / s

0 0 <0.707 not used
1 1 0.707 357.796
2 2 1,000 253,000
3 3 1.414 178.898
4th 4th 2,000 126,500
5 5 2.828 89.449
6th 6th 4,000 63,250
7th 7th 5.657 44.725
8th 8th 8,000 31.625
9 9 11,314 22,362
10 A. 16,000 15.813
11 B. 22.627 11,181
12 C. 32,000 7,906
13 D. 45.255 5,591
14th E. 64,000 3.953
15th F. 90.510 2,795

literature

  • Wilhelm Gerster: Modern lighting systems for indoors and outdoors. 1st edition, Compact Verlag, Munich, 1997, ISBN 3-8174-2395-0

Web links

Individual evidence

  1. ↑ Product description Vossloh-Schwabe