Characteristic Adjustment Of The Linear Lighting Curve - ABB i-bus KNX Product Manual

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ABB i-bus KNX
Planning and application
4.12.1

Characteristic adjustment of the linear lighting curve

The DALI characteristic compliant to IEC 62386-102 described in the previous chapter can be modified via
the DALI Light Controller, so that it provides a linear characteristic from KNX brightness value [%] to
luminous flux.
Based on the KNX brightness value (row A or B), the DLR/S calculates the corresponding DALI control
value (column C), which is required to achieve the same luminous flux (column D) from the figure value.
Thus, a brightness value on the KNX of 3 % (digital value 8) is also provided as a luminous flux of 3 %.
This has the benefit that the KNX value range can be used almost completely for the brightness value. In
this way, the light yield of the lighting equipment has not changed. Furthermore, it must be considered that
the perceived linear brightness response due to the logarithmic DALI curve is no longer available.
In an ideal case, the following transformation table results:
KNX status
E
brightness value
Luminous flux
D
[%]
C DALI value
B KNX value
A KNX value [%]
With the linear characteristic, a dimming range of 3...100 % results with a DALI device as featured in the
following table:
KNX status
E
Brightness value
Luminous flux
D
[%]
C DALI value
B KNX value
A KNX value [%]
The marked values are again the values, which result for a ballast with a dimming range of 3 %...100 %.
It becomes evident that, on the KNX, the variables for the brightness value between 3 % and 100 % can
be used (row A), even though the DALI value (row C) changes between 126 (50%) and 254 (100%).
0 3 8 13 26
0 1 3 5 10
0 85 126 144 170
0 3 8 13 26
0 1 3 5 10
0 3 8 13 26
0 1 3 5 10
0 85 126 144 170
0 3 8 13 26
0 1 3 5 10
51 77 102 128 153
20 30 40 50 60
195 210 220 229 235
51 77 102 128 153
20 30 40 50 60
51 77 102 128 153
20 30 40 50 60
195 210 220 229 235
51 77 102 128 153
20 30 40 50 60
DLR/S 8.16.1M | 2CDC 507 100 D0202 197
179 204 230 255
70 80 90 100
241 246 250 254
179 204 230 255
70 80 90 100
179 204 230 255
70 80 90 100
241 246 250 254
179 204 230 255
70 80 90 100