ABB i-bus KNX Product Manual page 192

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ABB i-bus KNX
Planning and application
The brightness value associated with the offset is sent via the communication object Master offset
brightness from the light controller lighting group. Alternatively, this brightness value can also be internally
transferred to the slave in the light controller.
In this example, lighting strip 1 is compiled to a light controller lighting group. The slave lighting group
consists of the lamps of lighting strip 2. A value of -20 % is parameterized as an offset. In this way, lighting
strip 2 is controlled with a brightness value that is 20% less than the brightness value of the master. The
following brightness values result:
Master brightness value
As soon as the daylight starts to fade, the area of the room beside the window is no longer provided with
sufficient natural lighting. The side of the room beside the window now receives too little artificial lighting to
ensure optimum working conditions. In order to automatically counteract this natural behavior, it is possible
for each light controller lighting group in the DALI Light controller to use the communication object Master:
Offset activate to switch off the offset via the KNX. Thus the slave is controlled with same brightness level
as the master.
Switching ON and OFF the offset can, for example, be implemented using a twilight sensor switch or a
timer.
As a result, there is always sufficient brightness in the room with the minimum of energy consumption.
190 2CDC507128D0202 | DLR/A 4.8.1.1
Brightness value of slave
100 % (255)
75 % (191)
50 % (126)
20 % (50)
10 % (26)
0 % (0)
80 % (205)
60 % (153)
40 % (101)
16 % (40)
8 % (21)
0 % (0)