DALI (Digital Addressable
Lighting Interface) is a new standardized digital protocol for dimmable HF
ballasts. Behind DALI are the major manufacturers of HF ballasts in Europe lead by
Helvar, Osram, Phillips and Tridonic. In recent times several other European
companies within the lighting industry have signed up to DALI, and there is
no doubt that DALI will have a large impact on the lighting industry during
the coming years.
Today, there are two fundamental
ways to dim, using analogue 1 – 10V technology or digital technology. When we
speak of the digital technology, Tridonic has since the start of the Nineties
worked with its DSI-system (Digital Serial Interface) and how DALI has
arrived, which is a new standard for controlling HF ballasts via a digital
control signal.
A
summary of the DALI-protocol’s technical advantages
·Addressing, 64 addresses give
the possibility of individual control of more control gear/luminaires
connected to the same control cable.
·Light scenes, possibility to
programme different light scenes for different purposes. Each system can be
configured for max. 16 groups, and in each group a maximum of 16 different
scenes can be programmed.
·Switching on and off can be
controlled from digital bus.
·The digital bus has no polarity
(positive/negative) and can be routed with the conductors for the mains
voltage even over long distances. In older installations, the bus can be
routed separately, under the condition that all conductors are insulated from
the conductor that has the highest voltage. No screened cables are necessary.
·Digital signals, which are exact
and interference free, i.e. not affected by fluctuations in the mains voltage.
·Two/way communications are
possible, e.g. status and error messages.
·The control signal makes, among
others, eye adapted light control possible (“logarithmic control”).
·The signal is exact and is
experienced as always being the same by all HF ballasts.
·The signal can communicate in
both directions and can send error messages from the luminaire, e.g. when
relamping is necessary.
·The digital technology is also
ideal for control and regulation via computers and it allows control in an
exact and reliable manner.
·The system is flexible and easy
to install, the lack of polarity (+ and -) on the digital bus reduces the
risk of incorrect connection in installations.
·Digital regulation can take
place using sensors, detectors, IR-remote controllers, etc. via different
control modules (interface).
·The digital technology can
easily be integrated in installations with a central building management
controller (e.g. EIB or Lonworks) via special control modules (interfaces).
HF-ballast,
DALI
DALI ballasts, irrespective of
manufacturer, will be able to understand and be controlled using the common
DALI-protocol. However, DALI ballasts from different manufacturers will have
variations with regards to performance and characteristics. There are already
ballasts available that can be controlled with either 1 – 10V or DALI.
Helvar has chosen to integrate a power supply in its ballast, which
means that installations can be set up without the need of connecting a
separate power supply.
Application areas
DALI will primarily be used in
smaller installations such as cellular offices, office landscapes, conference
rooms, etc. DALI is not a new system for building management.On the other hand it is obvious that
special control modules will be available so that DALI ballasts can be
integrated in properties with BMS (Building Management System) via gateways
to both EIB (European Installation Bus) and Lonworks. In order to get the
best results from DALI there should be a need of individual control
(addressability).
For smaller installations, where
addressability does not come into question, as with the control of individual
luminaires DALI will not always be the optimal solution. It may then be
simpler and less expensive to use an existing analogue or digital system.
