ABB i-bus KNX Product Manual page 62

®
ABB i-bus KNX
© 2008 ABB STOTZ-KONTAKT GmbH
Commissioning
furniture) differ significantly from the original ambient conditions at
the time of calibration.
Deviations may also occur if the Light Sensor is influenced by direct
or reflected light falling on it which is not influenced or only slightly
influenced by the surfaces in the detection range of the Light Sensor."
Note
Luminaries with varying brightness characteristic curves should be
avoided in control circuits. In a Light Controller control circuit a mix
of 1-10 V luminaries and DALI luminaries (controlled via DALI
gateways) is not possible.
This is because of the different brightness characteristic curves
(linear/logarithmic) involved. The same control value, e.g. of 50 %
with 1-10 V luminaries causes a brightness of 50 %. Using DALI
luminaries where the characteristic curve is adapted logarithmically
to the response of the human eye, a light current of 3 % results in a
brightness level of about 3 %.
Because of these brightness differences at the same control value,
a common lighting control (in a Light Controller control circuit) is not
possible.
A switch on telegram to the object Switch always activates light
control. The active control dims the illumination so that the difference
between the Light Sensor actual value and the setpoint value is as
small as possible.
After a download with parameterised Light control this is active and
starts controlling.
Response of the lighting control during and after bus voltage
failure:
Bus voltage failure
Bus voltage recovery
Control is not possible without bus voltage.
The contact of the output assumes the switching
position as defined in parameter window
with bus voltage failure.
Light control is active and controls the setpoint value
directly after bus voltage recovery. If the switch object
is written with a 0 at bus voltage recovery, the lighting
will be switched off again and the light control will go to
standby mode.
X: General
60