ABB i-bus KNX Product Manual page 133

®
ABB i-bus KNX
© 2008 ABB STOTZ-KONTAKT GmbH
Planning and application
If the increment is too large, the light control reaches the setpoint faster.
The setpoint brightness is exceeded. The Light Controller starts to oscillate
around the setpoint brightness.
Brightness
Setpoint
brightness
Actual
brightness
T = step time
If the increment is too small, it will take too long until the setpoint brightness
is reached. This is critical particularly where blinds which are closing to
darken the room quickly.
Brightness
Setpoint
brightness
x increments
Actual
brightness
The increment time should be selected so that the brightness change of
a control step is available via the Light Controller/luminaire/Light Sensor
before the next control step is triggered. Otherwise the brightness setpoint
will be exceeded and has to be regulated back a step. Normally the Light
Controller determines these control variables.
If required these variables can be set individually in the parameter window
Dynamics. The parameter window X: Control Dynamics is visible
X: Control
if in the parameter window
during lighting control is set to individual setting. The parameterised
variables are written in the following illustration.
Y
T
Y
T
x increments
the parameter Changing brightness
X: Control
Y = increment
Y
T
T
Time
Time
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