Osram DALI MCU User manual

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www.osram.com/ecg-lms
Professional-Practice
DALI MCU: Digital potentiometer with DALI
Manual lighting control with the DALI MCU for rooms with grouped luminaires with
as many as 50 ECG, with or without dividing wall
1. Application
Consider you want to switch on/off and dim the light
in a room, a restaurant or bar, a foyer or lounge etc
– but you want to do it from either of its two doors,
no matter which. For this to work, the two control
points would have to operate synchronously in such
a fashion that the lighting system responds
immediately and harmoniously when the brightness
level is changed at either of the control devices.
With the DALI MCU digital potentiometer, it is easy
to meet such requirements.
The parallel connection between the two devices
(control points), which would be required for our
example to work, becomes super simple – and it
does not necessitate any demanding installations
and/or additional control components.
Each control circuit simultaneously affords the
integration of as many as 50 luminaires and of up to
4 DALI MCU control devices (control points). And all
that while allowing for the required comfortable,
easy and complete control over the lighting levels at
any time.
03 User benefits
04 Installation
05 Wiring for a
conference room
06 Operation
07 Other fields of application
08 Technical data
Content
01 Application
02 Setup/Function of
components

APPLICATIONS DALI MCU
2. Setup/Function of components
The components in our example (page 1) above comprise
the following::
•12 ceiling lamps, fitted with DALI ECG (e.g. QTi
DALI…DIM)
•2 DALI MCU control devices, which will be
integrated in standard flush-mounting electrical
boxes..
In installations with 2 to 4 parallel-connected DALI MCU
control devices, the command triggered by the device last
operated, will determine the current switching state and/or
the brightness value in the room. At the same time, the
command is transmitted to the other devices, which will
automatically tune to the same value. Subsequent
changes of lighting levels from another control point will
therefore not cause any annoying side effects such as
sudden changes in luminous power because of different
switching positions of the other control points that may
have been operated previously.
Figure 2: DALI wiring layout
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APPLICATIONS DALI MCU
3. User benefits
Lighting levels in the room can be controlled from any of the
two control points. The control device most recently used will
determine the current operating condition of the entire
lighting system, i.e. of all luminaires and control devices
integrated into that control circuit.
Use of the control devices is really simple, because:
•switching the light on/of is by single pressure of the
rotary knob and
•by turning the rotary knob to the left or right, you
can set the required brightness value.
Moreover, you can also ask the DALI MCU to store a
particular brightness value by double-pressing the rotary
knob (double-click). The next time the light is turned on, the
system will then automatically return to this lighting level.
The digital potentiometer has no mechanic turning limit in
either direction and brightness values are set in small
individual mechanical steps. Therefore, the required
brightness can be set comfortably and accurately at a high
resolution.
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APPLICATIONS DALI MCU
4. Installation
The installation used in our example (figure 2) should be
done as follows
The mains supply to the luminaires and to one of the two
DALI MCUs control devices may run through the same or
through different phases (by means of a single conductor or
by a 5-pole NYM cable).
In our circuit, one of the two DALI MCUs control devices
must be supplied with 230V mains power. The second
control device will operate without a separate mains supply
in the same control circuit. With this setup, you can control
up to 25 ECG independent of their power consumption. Each
DALI ECG comes with the interface that has a power
consumption of approx. 2mA. The internal power supply of a
DALI MCU connected to the mains will provide approx.
52mA – enough to supply up to 25 ECG and another DALI
MCU not connected to the mains.The following wiring
diagram (figure 3), for example, shows that the control
device labelled “Door A” has a mains connection. Likewise,
the control device “Door B” could get the mains connection
instead. This wiring diagram is based on the use of a 5-pole
NYM cable and supply for the entire lighting system through
one Phase (L and N).
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APPLICATIONS DALI MCU
5. Wiring
Figure 3: Wiring scheme of a conference room
You can control up to 25 ECG with this setup (figure 3). If
you also connect the second control device to the 230V
mains, you can operate up to 50 luminaires and two
additional DALI MCUs without mains connection in one and
the same control
circuit (i.e. 4 control points in total – figure 4). However, it is
not permissible to connect more than two control devices in
the same control circuit to the mains.
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APPLICATIONS DALI MCU
Figure 4: Wiring scheme with 4 control points for addressing up to 50 ECG
Laying the control line in indoor installations is generally not
difficult. For the two control wires (DALI signal), you can use
two wires in the same 5-pole NYM cable that provides the
mains supply. You may chose any arrangement for the
parallel wiring, but a closed circuit of the control line is not
permissible. Moreover, the total running length of the control
line must not exceed 300m.
It is important to observe correct polarity of the feed cables
when connecting the control line with two or more DALI MCU
control devices.
Because each of the devices has its own power supply, the
connections must not be mixed up – i.e. the positive wire
must be connected to Da+ and the negative wire must be
connected to the Da- connector of the control device.
Erroneous wiring, however, will not destroy the device,
because the DALI MCU comes with an inverse-polarity
protection feature – however, correct operation will only
resume when the wiring has been corrected to match device
polarity. It is not necessary to observe control line polarity on
the ECG side.
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APPLICATIONS DALI MCU
6. Operation
The digital potentiometer comes with two different features: it
responds to button pressure and left/right rotation without a
mechanical end point (incremental encoder). Short pressure
on the rotary knob will switch the light on/off, and anti-
clockwise rotation of the knob (turn to the left) will cause a
reduction of brightness, while clockwise rotation (turn to the
right) will increase brightness.
Storing switch-on brightness
As you switch the light off with a short pressure of the rotary
knob, the DALI MCU will store the current brightness value.
This value will be recalled when the light is switched back on
the next time. However, the DALI MCU control device also
allows you to store a fixed switch-on value, which will be
recalled every time the light is switched on, irrespective of
the value which the system was set to as the light was
switched off. Storing the switch-on value is very easy: simply
turn the knob to the required brightness and then store the
value by briefly pressing the rotary knob twice (double-click).
To confirm that the DALI MCU has stored the value, all
connected lamps will briefly brighten once. Irrespective of the
brightness value last used (but not stored) before the lights
were switched off, the system will automatically set
brightness to the level stored by the DALI MCU.
RESET: Of course you can also reset the system to its
default setting in which the brightness value used before
switching-off the light will be restored when the light is
switched back on the next time. To do so, switch off the light
by pressing the rotary knob once and double-click it while the
lights are still off. Again all connected lamps will briefly
brighten once to confirm that the DALI MCU has been reset.
Setting a basic brightness level
We recommend setting a basic brightness level (minimum
dim setting) of the lamps when using the system for the first
time. To do so, take the following steps:
Reduce brightness when the light is on until you can no
longer determine any further reduction of the luminous
power. Press the rotary knob for a longer time (approx. 10s)
to tell the DALI MCU to store this value as the basic
brightness level. Again the lamps will briefly brighten once to
confirm that the value has been set.
If you do not set a basic brightness level, the DALI MCU
might under certain conditions trigger lighting levels that are
outside the dimming range of the connected ECG. To
increase the luminous power in such a case, you would have
to turn the rotary knob way to the right until sufficient power
is put out – this can be a nuisance.
RESET: If you want to reset the system to its default settings
with a dimming range of 0…100 %, switch off the light by
briefly tapping the rotary button and then press the knob for
about 10 seconds while the lights are still off. Again all
connected lamps will briefly brighten once to confirm that the
DALI MCU has been reset.
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APPLICATIONS DALI MCU
7. Other fields of application
Consider you have a similar room with a retractable dividing
wall, such as a conference room, a public hall or a
restaurant. When the dividing wall is closed, you want both
sections of the room to be individually dimmable and you
want to be able to switch lights off/on in either section
independently. When the dividing wall is open, however, you
want to control lighting synchronously across the entire room
(both sections) from any of the control points. To achieve
this, you would set up one DALI control circuit in each of the
sections You would then connect one control device in each
section (figure 5) to the mains, and optionally, you could also
install a second control device without mains connection in
each of the sections.
One DALI MCU control device in each of the two sections
must have a mains connection to make sure that it can
supply its assigned control circuit when the dividing wall is
closed.
When the dividing wall is closed, the position switch is in
open position, so the connection between the two control
circuits is broken. Then, lighting can be controlled and
dimmed in both sections independently.
When the dividing wall is open, the position switch is in
closed position and the control circuits in both sections and
their corresponding control points are turned into one single
parallel-connected control circuit. You will therefore be able
to control all lamps in both sections simultaneously. Please
pay special attention when connecting the control lines to the
terminals of the DALI MCUs (polarity!). Single-pole
interruption of the DALI control line via the position switch is
generally permissible. It does not matter, which of the two
control wires (Da+ or/and Da-) is used for switching or
whether both are used. As soon as the previously closed
dividing wall is opened – connecting the previously
interrupted DALI cable between the control devices in both
sections – illumination levels in both sections will adjust to a
uniform brightness within approx. 10 seconds. The
brightness level will match the level previously set in one of
the sections. Turning the knob on any of the DALI MCUs will
then change the lighting in the entire room based on this
previous level.
Figure. 5: DALI wiring layout in a dividable room
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APPLICATIONS DALI MCU
Figure. 6: Wring scheme of a room with partition
Additional interesting uses of the DALI MCU include
dimmable individual luminaires, groups of luminaires, custom
settings in RGB colour mix systems with designer lamps or
decorative lamps, and the control of fluorescent lamps with
different colour temperatures in daylight luminous ceiling
applications, LED colour tile systems or in illuminated
displays (signage).
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APPLICATIONS DALI MCU
8. Technical data
Designationg DALI MCU
Order reference (EAN) 4008321189721
Power connection L, N
Operating voaltage 230 V AC, 50-60 Hz
Power consumption 3 W max.
DALI connection da+/da-, max. 300 m cable
legth,25 DALI ECG max.
Perm. Cable cross-section 1…4 mm2
Ambient temperature 0…+50 °C
Type of protection IP 20
Protection class II
CE requirement EMC to EN 61547, low
voltage to EN 60628
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