User Guide
190-00592-02 Rev. A
Garmin G1000 Pilot’s Guide for the Diamond DA40/40F
4-26
AUDIO PANEL AND CNS
4.4 GTX 33 MODE S TRANSPONDER
The GTX 33 Mode S Transponder provides Mode A, Mode C, and Mode S interrogation and reply capabilities.
Selective addressing or Mode Select (Mode S) capability includes the following features:
• Level-2 reply data link capability (used to exchange information between aircraft and ATC facilities)
• Surveillance identifier capability
• Flight ID reporting – The Mode S Transponder reports aircraft identification as either the aircraft registration or
a unique Flight ID (Flight Identification).
• Altitude reporting
• Airborne status determination
• Transponder capability reporting
• Mode S Enhanced Surveillance (EHS) requirements
• Acquisition squitter – Acquisition squitter, or short squitter, is the transponder 24-bit identification address.
The transmission is sent periodically, regardless of the presence of interrogations. The purpose of acquisition
squitter is to enable Mode S ground stations and aircraft equipped with a Traffic Avoidance System (TAS) to
recognize the presence of Mode S-equipped aircraft for selective interrogation.
The Hazard Avoidance Section provides more details on traffic avoidance systems.
TRANSPONDER SOFTKEY CONTROLS
Transponder function is displayed on three levels of softkeys on the PFD: Top-level, Mode Selection, and
Code Selection.
When the top-level
XPDR
Softkey is pressed, the Mode Selection softkeys appear:
STBY
,
ON
,
ALT
,
VFR
,
CODE
,
IDENT
,
BACK
.
When the
CODE
Softkey is pressed, the number softkeys appear:
0
,
1,
2
,
3
,
4
,
5
,
6
,
7
,
IDENT
,
BKSP,
BACK
. The digits
8
and
9
are not used for code entry. Pressing the numbered softkeys in sequence enters
the transponder code. If an error is made, pressing the
BKSP
Softkey moves the code selection cursor to the
previous digit. Pressing the
BKSP
Softkey again moves the cursor to the next previous digit.
Pressing the
BACK
Softkey during code selection reverts to the Mode Selection Softkeys. Pressing the
BACK
Softkey during mode selection reverts to the top-level softkeys.
Pressing the
IDENT
Softkey while in Mode or Code Selection initiates the ident function and reverts to the
top-level softkeys.
After 45 seconds of transponder softkey inactivity, the system reverts back to the top-level softkeys.