ABB i-bus KNX Product Manual page 183

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ABB i-bus KNX
Planning and application
The increment time should be selected so that the brightness change of a control step is available to the
DLR/A 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 DLR/A determines these control variables. If required, these variables can be set individually
in Parameter window - Gx Light
Changing brightness during lighting control the option individual setting is selected.
The parameterized variables are written in the following illustration.
In the start-up phase (1), the Step time for fast approach (T1) of the control step can be parameterized.
The smaller this time, the faster the control steps are sent with the calculated step increment (Y1). The
setpoint brightness is approached in a relatively short time.
If the difference between the setpoint brightness and the actual brightness has undershot a parameterized
value, the fine tuning phase (2), in which the Step time for slow approach (T2) slowly approaches, the
setpoint value commences.
The step increment (Y2) can also be parameterized to reach the setpoint faster or slower. This increment
only is valid until a determined interval to the setpoint value. This interval can be set via the parameter
Control deviation for high increments (max. control step).
With an additional parameter (Control deviation for high increments), you set the phase (3), in which the
lighting control is suspended. A range around the setpoint value, where there is no light control, must be
parameterized. Only when the actual brightness is again larger than this difference will the light control
recommence. In this way, continuous control with the respective changes in brightness is avoided. This
generates a smoother and less abrupt response and considerably reduces the KNX bus load with a
master/slave control.
controller, page 95. The parameters are enabled if in the parameter
DLR/A 4.8.1.1 | 2CDC507128D0202 181