AXP340 Transponder Installation Manual
10 March 2014
01201-00
Issue AF
AVIDYNE CORPORATION
Page 23
screens. You may select Flight level (100’s of feet), feet or meters.
6.1.16
Lighting Control
The AXP340 has an integrated ambient light sensor in addition to an external input connection from the
aircraft lighting bus (if available). This configuration setting selects the way in which the integrated light
sensor and the lighting bus input control the brightness of the LCD and the bezel.
Selected Method
Description of lighting control
Normal mode
The display brightness/backlighting is controlled from the
ambient light sensor and the bezel is controlled by the
lighting bus.
Bus Only
The lighting bus is used to control the bezel and the display
brightness/backlighting.
Sensor Only
The ambient light sensor is used to control the bezel and the
display brightness/backlighting.
6.1.17
LCD Dim Point
Depending on the amount of light spill in the cockpit, and the brightness of other adjacent avionics displays,
it may be necessary to adjust the darkest setting of the backlight to best match other equipment and to
improve the cockpit appearance.
Note – it is only practical to do this in pitch darkness, since that is the in-flight environment that you are
trying to reproduce. If you are working in a hangar with any other lighting it may be better to leave the
setting in the mid-range.
6.1.18
LCD Brightness
The actual maximum brightness of the LCD cannot be increased with this control. What it controls is the
rate at which the lighting increases in brightness as detected by the ambient light sensor. This allows the
brightness to be matched to other avionics displays during light level changes as far as possible.
6.2 Test items
6.2.1
Interface Check
The Interface Check screen displays the current state of the external IDENT, external STANDBY and
external GROUND inputs. Exercise these inputs to confirm the correct behaviour.
6.2.2
Altitude Check
The Altitude check displays the current state of the altitude inputs. Individual Gray code lines are shown to
assist in fault tracing.
6.2.3
Lighting Bus
The lighting bus check displays the voltage on the lighting bus to assist in verifying the correct operation of
the lighting bus.
6.2.4
Temperature
The internal temperature of the transponder may be accessed only in maintenance mode. This is for
information only and does not provide any diagnostic value. Display is in degrees Celsius.
