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

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ABB i-bus KNX
Planning and Application
4.10.1

Characteristic adjustment of the linear dimming curve

The DALI characteristic compliant to IEC 62386-102 described in the previous chapter can be modified via
the DGN/S 1.16.1, 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 DGN/S calculates the corresponding DALI control
value (row C), which is required to achieve the same luminous flux (row 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:
A KNX value [%]
B KNX value
C DALI value
D Luminous flux [%]
KNX status brightness
E
value
With the linear characteristic, a dimming range of 3...100 % results with a DALI device as featured in the
following table:
A KNX value [%]
B KNX value
C DALI value
D Luminous flux [%]
KNX status brightness
E
value
The marked values are again the values, which result for a ballast with a dimming range of 3 %...100 %. It
becomes clear that when on the KNX the control values for the brightness value between 3 % and 100 %
are used, the emitted light yield range does not change.
0 1 3 5 10 20
0 3 8 13 26 51
0 85 126 144 170 195
0 1 3 5 10 20
0 3 8 13 26 51
0 1 3 5 10 20
0 3 8 13 26 51
0 85 126 144 170 195
0 1 3 5 10 20
0 3 8 13 26 51
30 40 50 60 70 80
77 102 128 153 179 204
210 220 229 235 241 246
30 40 50 60 70 80
77 102 128 153 179 204
30 40 50 60 70 80
77 102 128 153 179 204
210 220 229 235 241 246
30 40 50 60 70 80
77 102 128 153 179 204
DGN/S 1.16.1 | 2CDC 507 114 D0201 149
90 100
230 255
250 254
90 100
230 255
90 100
230 255
250 254
90 100
230 255