User's Manual

5
Fault Annunciation
If the transponder detects an internal failure, the screen will indicate FAULT
and a brief statement of the problem. No replies will be made to
interrogations when a fault is detected.
Some FAULT indications can be recovered by switching the transponder off
and back on again, although in all cases a FAULT code implies that there is a
fault with the transponder or the installation. Note the FAULT message at the
bottom of the screen and pass that information to your avionics maintenance
organisation.
Configuration Mode
The system is configured when it is first installed by your avionics supplier.
Configuration items include the Mode S aircraft address, the interface to the
other aircraft systems, the aircraft category, and the pre-programmed values
for VFR squawk code. To view or change these settings you must use
Configuration Mode.
Do not use Configuration Mode in flight. Check with your avionics
installer before changing the configuration.
To enter configuration mode, hold down the FUNC button whilst switching on
the transponder. Configuration items can be changed using the numeric
buttons 6 for down, 7 for up and the ENT button to accept the selection.
Pressing the 2 button will move back to the last menu item. Pressing FUNC
advances to the next configuration item.
When configuration is complete, switch the transponder off. When it is
switched back on the transponder will use the new configuration.
Low Temperature Operation
The KT74 is certified to operate correctly down to -25C, but at low
temperatures the display may be impaired. On a cold day you may need to
wait for the cockpit to warm up to ensure normal operation. A heating
element is built into the front panel to automatically raise the temperature
around the display under extreme cold conditions and reduce the time before
the display is fully functional. This heater may several minutes to become
effective after initial power on.