Garmin GNC 255 Installation Manual - page 59
190-01182-02
GTR 225/GNC 255 TSO Installation Manual
Rev. B
Page 6-5
6.4.1.5 Photocell
The Photocell page (Figure ) allows the installer to configure the parameters of the photocell. See Table 6-
4 for description of each parameter.
Figure 6-6. Photocell Page
Table 6-4. Photocell Page Parameter Description
Selection
Description
TRNSN (Transition)
When a lighting bus is used to control the lighting of the display, this parameter
sets the point on the lighting bus control below which the display brightness
tracks the GTR/GNC photocell. This field has a range of 5 to 50, and is set to 25
as the default setting.
SLOPE
Sets the sensitivity the brightness of the display or keys has to changes in the
photocell input level. Adjusting the slope higher will result in a brighter display
for a given increase in the photocell input level. This field has a range of 0 to
100, and is set to 50 as the default setting.
KEY CO (Key Cutoff)
This parameter configures the point at which key backlighting is switched off in
bright light. For example, a value of 70 results in the key backlights being turned
off at photocell source input levels above 70%. This field has a range of 0 (zero)
to 100 and is set to 80 as the default setting.
OFFSET
Adjusts the lighting level up or down for any given photocell input level. This
field has a range of 0 (zero) to 100, and is set to 50 as a default value. This may
also be used to match lighting curves with other equipment in the panel.