Garmin GTX330 Installation Manual page 38

4.6.2 RS-232 Input/Output, Software Update Connections
When the GTX 330 is installed in an aircraft an optional RS-232 serial data connector should be installed
in the aircraft for future software upgrades, negating the need to remove the transponder from the aircraft
panel. The connector can be mounted anywhere convenient for access, such as under the instrument
panel, on a remote avionics shelf or in the instrument panel itself. Be sure to label the connector for
Software Update. Do not include the Test Mode Select switch in the aircraft. See Figure 4-3 for software
update connections.
If the GTX 330 installation interfaces with a GNS 480 (CNX80) in the aircraft, the GNS 480 (CNX80)
must be turned off during GTX 330 software upload, due to loading of RS-232 port 1.
Software versions prior to 6.00 should not be loaded onto GTX 330 w/ES and
GTX 330D w/ES units.
A software conflict could result if older revision software is loaded into some
GTX330(D) units, which could cause backlighting failures. Do not load any software
versions prior to 4.00 into the following units.
Unit Name
GTX 330
GTX 330D
If the unit is removed from the aircraft and operated, always connect J3302, (and J3303
for GTX 330D) to an antenna or a 50 Ω, 5-Watt load. The GTX 330 transmits Mode S
acquisition squitter replies about once per second whether interrogations are received or
not.
The installation of an optional software upgrade connector is highly recommended. If the
connector is wired in the aircraft, transponder removal and reinstallation for software
upgrade is not required.
Beginning with SW version 3.06, the GTX 330 software can be updated in the Configuration mode as
well as in Test mode. Updating software in Configuration mode does not require the TEST MODE
SELECT switch. See Figure 4-3 for software update connections.
Page 4-10
Revision R
CAUTION
CAUTION
Garmin P/N
011-00455-00
011-00455-20
011-00455-10
011-00455-30
CAUTION
NOTE
Serial Number Affected
84113984 and above
84305559 and above
84205684 and above
84405736 and above
GTX 330/GTX 330D Installation Manual
190-00207-02