GTX 327 Installation Manual
Page 5-5
190-00187-02
Revision K
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 3 to 7, and is
set to 4 at the factory.
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, and is set to 8 at the factory. 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) (Auto Only)
Selection
Description
PHOTO (Photocell)
DEFAULT. Backlight level is determined by the ambient light level
as measured by the photocell on the GTX 327.
14V
Backlight level tracks a 14 Volt DC aircraft lighting bus.
28V
Backlight level tracks a 28 Volt DC aircraft lighting bus.
5V
Backlight level tracks a 5 Volt DC aircraft lighting bus.
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 will track the GTX 327 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 will be for a given increase in the input level. This field has a range of 0 (zero) to 99,
and is set to 50 at the factory.
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.
5.2.3 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.
KEY LIGHTING Page
