Code Selection - Garmin GTX 330 Installation Manual

5.1.2 Code Selection

Code selection is entered with eight keys (0 – 7) providing 4,096 active identification codes. Pushing one
of these keys begins the code selection sequence. The new code is not activated until the fourth digit is
entered. Pressing the CLR key moves the cursor back to the previous digit. Pressing the CLR key when
the cursor is on the first digit of the code, or pressing the CRSR key during code entry, removes the cursor
and cancels data entry, restoring the previous code. You may press the CLR key up to five seconds after
code entry is complete to return the cursor to the fourth digit. The numbers 8 and 9 are not used for code
entry, only for entering a Count Down time, contrast and display brightness, and data selection in the
Configuration mode.
NOTE
The selected identification code should be entered carefully, either one assigned by air
traffic control for IFR flight or an applicable VFR transponder code.
• Important Codes:
1200  VFR code for any altitude in the US (Refer to ICAO standards elsewhere)
2000  VFR code commonly used in Europe (Refer to ICAO standards)
7000  VFR code commonly used in Europe (Refer to ICAO standards)
7500  Hijack code (Aircraft is subject to unlawful interference)
7600  Loss of communications
7700  Emergency
Avoid selecting code 7500 and all codes in the 7600-7777 range. These codes trigger special indicators in
automated facilities. An aircraft's transponder code is used for ATC tracking purposes, therefore exercise
care when making routine code changes.
190-00207-02
Rev. U
GTX 330/330D Installation Manual
Page 5-3