DALI (Digital Addressable Lighting Interface) is a lighting industry specific protocol between control devices (controllers) and control gear (ballasts) formally specified by IEC62386.
DALI is a digital protocol used to control and query lighting. It was introduced as an annex to IEC60929 "A.C. Supplied electronic ballasts for tubular fluorescent lamps - Performance requirements" and has been implemented across a wide range of lamp types including LED, HID and Low Voltage Halogen. In 2009, a new set of standards, IEC62386 with various parts was introduced, replacing IEC60929.
DALI uses a modulated power system for communication both from control device to gear and back again. A current limited supply is deliberately pulled down by transmitters to produce low pulses, and released to produce high pulses.
Forward frames from control devices to control gear (ballasts) are 16 bits, and reverse frames from control gear are 8 bits (not counting start bit and stop bits). The information rate is low at 1200 bits/sec and the voltages high at 9.5-22.5V for a high, 0-6.5V for a low, so that there are no special requirements on the cables. Non twisted, non screened multicore cable can be run for 300m with other cores carrying mains current without detrimental affect on the DALI signals. It is only single insulated from mains in the cable and at the gear end, so is not a SELV signal.
Use of the DALI symbol on products is governed by the "DALI group" formerly known as AG DALI, a division of the ZVEI group, independent of the IEC standards body.
Questions that should have this tag should be about the lighting control protocol rather than the marketing group and logo, and be of a technical nature suitable for an electronics literate audience.
See also http://en.wikipedia.org/wiki/DALI_lighting
Anyone working with DALI should obtain a copy of the IEC62386 standards for reference since many sites and microprocessor app notes are still using IEC60929 Annex E.4. which is out of date. DALI is an open standard in that anyone can produce products that work to IEC62386 but it is not a free standard, and membership of the "DALI group" is required, as well as passing a suite of official tests, to use the DALI name and logo on products.
