DALI Topology

The DALI ECGs are wired in parallel to each other and groups are not taken into consideration. Star configurations are also possible. Ring wiring is not permitted (indicated by X in the diagram). There is also no need for terminating resistors on the communication cable.

DALI parameters in the ECG


The following data can be stored in the DALI ECGs when a DALI system is started up:

• Group assignment of the DALI ECG (max. 16 groups, multipleassignment is possible)

• Individual address for accessing each ECG directly (max. 64)

• Lighting values for the individual scenes (max. 16)

• ECG parameters that determine the behavior of the ECG:

• Dimming rate• Behavior if the voltage fails on the interface (System Failure Level)

• Behavior when the mains voltage is restored (Power On Level)In addition to the above-mentioned options, it is always possible toaddress all the devices together, even without programming


Requirements to be met by the transmission cable


When selecting a cable make sure that the voltage drop on the line does not exceed 2 V at 250 mA. As with 1…10 V systems, the power supply and control line can be run in the same cable. This means, for example, a 5-core NYM cable can be used to connect the DALI ECG without any problems. The maximum permitted total length of cable between the controller and the connected ECG is 300 m.


Cross section of the power cable:

A = L x I x 0.018

A = Line cross section in mm², L = Cable length in meters,

I = Max. current of the supply voltage in A,

0.018 = Specific resistance of copper


The following formula is used as a basis for finding the cable crosssection (transmission and power cable):


Line length                up to 100 m        100 to 150 m          150 to 300 m

Line cross section         0.5 mm2             0.75 mm2               1.5 mm2




Because of the different technical properties of the DALI interface in control units found on the market and the differing local conditions of the installation, it is recommended to limit the overall line lengths used in the system to 300 m.