What does the DALI message look like?
DALI is a digital protocol. Signal levels are defined as:
- 0 V (±4.5 V) for “0” and 16 V (±6.5 V) for “1”.
- The maximum DALI current per system or subnet is 250 mA and the load interface maximum current is 2 mA per unit.
- The network cable must be mains-rated, with 600 V isolation with a maximum drop of 2 volts along the cable (max 300 meters).
Basic Rules for DALI products & systems
There are a few basic rules to take into account when planning and wiring a DALI system.
Max. Addresses per system (subnet)
63, it’s officially 64, but you need to leave one free, to make system updates easier.
In general, DALI connections are not polarity sensitive. The manufacturers’ instructions should always be checked for exceptions.
Max. DALI current per system (subnet)
250 mA DALI supply.
The total current that is supplied by all sources of the control system must not be more than 250mA.
DALI wiring safety rating
DALI wiring and connections should be treated like Mains voltage wiring. Though the signal is 16 volt the hardware is not SELV rated (Safety Extra Low Voltage).
Which wire for DALI cable?
You must use 2-conductor, mains rated wire.
Maximum cable length
|Less than 100 meters||0.5 mm^2|
|100 to 150 meter||0.75 mm^2|
|More than 150 meters||1.5 mm^2|
|More than 300||Not recommended|
If you are having problems with a DALI system, check these things first
Check the number of addresses: 63 or fewer
Check the total current consumption of all the devices connected is not more than 250 mA.
Check cable length: The total cable length should not be more than 300m.
Check DALI signal voltage
Use a suitable multi-meter check the DALI signal voltage. Ideally, the measured voltage should be between 16 V DC and 22.5 V
DC with no more than a 2 V DC drops along the cable length. If you read less than 14 V DC, it is likely that you have, or will have, a problem with your DALI system.
For more information about DALI drivers, please click the article below.