Garmin Apollo CNX80 Installation Manual - page 92
Post-Installation Configuration & Checkout
3-18
560-0982-01 Rev A
GNS 480 (CNX80) Installation Manual
3.2.1.8.5 Diagnostics
While on the GTX Main Setup menu page, press the
DIAGNOSTICS
line select key to display limited
information to aid in troubleshooting the transponder. The GTX Diagnostics setup page is shown in
Figure 3-17.
Figure 3-17 – GTX Diagnostics Page
GILLHAM ALTITUDE
If Gillham altitude is provided to the GTX transponder, this field will display the value of the Gillham
altitude that the transponder is reading. If Gillham altitude is not being provided to the transponder,
INVALID will be displayed.
NOTE
The GTX 32/327 transponder does not currently support this function, so INVALID will
always be displayed, even if the transponder is receiving valid Gillham altitude.