Table 5-5 Backlight Source Selections - Garmin GTX 330 Installation Manual

LVL (Level)
Shows the current level of display backlighting, based on the lighting input source (lighting bus voltage, or
the ambient light if the source is PHOTO) and the settings on this configuration page. This field has a
range of 0 (zero) to 999. The level is set by pressing the 8 and 9 keys when MAN mode is selected. When
in AUTO mode, the field is for display only.
RSP TIME (Response Time)
Sets the speed with which the brightness responds to ambient light changes (only for AUTO backlight
mode). The higher the number, the slower the display responds. This field has a range of 0 to 7, with the
default set to 4.
MIN (Minimum) (Auto Only)
Sets the minimum brightness of the display. The higher the number, the brighter the minimum brightness.
Display minimum brightness has a range of 0 (zero) to 99, with the default set to 8. It is prudent to verify
that display lighting characteristics match those of other equipment in the panel under night lighting
conditions.
BKLT SRCE (Backlight Source)
SELECTION
PHOTO (Photocell)
14V
28V
5V
NOTE
If a lighting bus (any selection other than PHOTO) is selected, and the lighting bus
control is turned to its minimum (daytime) setting, the display brightness tracks the
GTX 330 photocell.
SLOPE (Auto Only)
Sets the sensitivity of the display brightness to changes in the input level. The higher the number, the
brighter the display for a given increase in the input level. This field has a range of 0 (zero) to 99, with the
default set to 50.
OFFSET (Auto Only)
Adjusts the lighting level up or down for any given input level. This field has a range of 0 (zero) to 99, and
is set to 50 at the factory. This may also be used to match lighting curves with other equipment in the
panel.
5.2.6 Key Lighting Page
The key lighting mode is always the same as the display
backlight mode, so the mode must be changed on the Display
Backlight configuration page. If the lighting mode is AUTO,
then the key lighting parameters can be edited on this page.
GTX 330/330D Installation Manual
Page 5-8

Table 5-5 Backlight Source Selections

DEFAULT. Backlight level is determined by the ambient light level as
measured by the photocell on the GTX 330.
Backlight level tracks a 14 Volt DC aircraft lighting bus.
Backlight level tracks a 28 Volt DC aircraft lighting bus.
Backlight level tracks a 5 Volt DC aircraft lighting bus.
DESCRIPTION
KEY BACKLIGHT Page
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