ABB i-bus KNX Product Manual page 64

®
ABB i-bus KNX
© 2008 ABB STOTZ-KONTAKT GmbH
Commissioning
Setpoint
Artificial light
calibration
The setpoint is the decisive control value in practical
application for constant lighting control.
The Light Controller calculates the setpoint for the lighting
so that the actual value to be set is as near as possible to
the predefined setpoint with all room lighting conditions.
Due to the differing ambient conditions in rooms (incidence
of light, reflections and absorption conditions) this setpoint
can not be easily achieved via the figure value defined in
the ETS, but must rather be set using a daylight and
artificial light calibration. With this calibration the lighting
characteristic and the technical lighting properties of the
room are automatically detected by the Light Controller in
order to match the control parameter to the room.
For further information see: Constant lighting control
Irrespective of this calibration, overshoot or undershoot of
the setpoint lighting value can occur during phases in
ongoing operation of constant lighting control. These are
even greater with greater differences of the reflection and
absorption conditions from the original ambient conditions
during the calibration procedure. A further possibility for
deviations is a direct or indirect incidence of light on the
Light Sensor, which does not or only barely affects the
area detected by the sensor.
With artificial light the Light Controller determines the
internal actual value which results with the required
setpoint value if artificial lighting is switched on exclusively.
The artificial light calibration should be undertaken without
the influence of daylight. The lighting should be set so that
the required setpoint in the room is set exclusively using
artificial lighting which is available during light control in the
room.
During the artificial lighting calibration the Light Controller
automatically determines the characteristic curve of the
lighting and detects the technical lighting properties of the
room. The required room brightness (setpoint) is set
exclusively using artificial light. The artificial lighting
calibration is triggered by a telegram with the value 1 to
the object Calibration lighting. During the calibration the
Light Controller automatically progresses through the
brightness characteristic from maximum to minimum
brightness. In this way, the brightness characteristic of the
room, the operating point and the associated parameters
for light control are determined. If the brightness curve has
been run through and the control parameters have been
automatically set, the Light Controller switches the lighting
to maximum brightness.
Artificial lighting calibration must always be undertaken.
The sequence of daylight and artificial light calibration is
not in any desired order. Calibration with artificial light
must be performed before calibration with daylight.
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