Dali Lighting Curve - ABB i-bus KNX Product Manual

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ABB i-bus KNX
Planning and Application
4.10

DALI lighting curve

The DALI lighting curve does not apply for emergency lighting converters. For this reason, the curve trans-
formation function is not used on the emergency lighting converter.
The DALI dimming curve is adjusted to the sensitivity of the human eye. In this way, a logarithmic charac-
teristic curve results for the luminous flux, which is perceived by the human eye as a linear brightness cha-
racteristic.
Note
The IEC 62386-102 describes the DALI values as arc power across the light source, which in most
cases is an almost linear relationship to the luminous flux.
The luminous flux describes the lighting power emitted from a light source in all directions. The unit is
stated in lumens (lm).
For the luminous flux under DALI, the characteristic shown in the following illustration is defined compliant
to the DALI standard (EN 60929 or IEC 62386-102):
The following DALI characteristic thus results:
100
90
80
70
60
50
40
30
20
10
Uncompensated DALI lighting curve for 8 bit control value [0...254]
0
0 50
X (n) - X (n + 1)
= konst. = 2,8 %
X (n)
100 150
KNX value [8 bit]
200
DGN/S 1.16.1 | 2CDC 507 114 D0201 147
250