Functional Descriptions 2.8.1 Power; Micro Aircraftp - Garmin GDL 90 Installation Manual

2.8 Functional Descriptions
2.8.1 Power
Aircraft power is provided to the GDL 90 on the main system connector. The GDL 90 will accept input
power from 10 to 40 VDC.
P1-1 Power +
P1-9 Power +
P1-2 Power Ground
P1-10 Power Ground
Refer to Appendix C for recommended power connections.
Operating the GDL 90 without RF terminations on the Top or Bottom UAT Antenna
ports can result in equipment damage. Always operate the GDL 90 with the Top and
Bottom UAT Antenna ports terminated with a VSWR ratio of 3.0:1 or less.
2.8.2 Micro Aircraft Personality Module (APM)
The GDL 90 stores installation-specific configuration information in an aircraft personality module
located on the rear of the mounting tray. This eliminates the need to set up the configuration again if a
new GDL 90 is installed. Since APM contains no lightning protection, the wire length from APM to
GDL 90 must be limited to 4 inches maximum.
P1-6 APM TxD
P1-7 APM RxD
P1-14 APM GND
Refer to Appendix C for interconnect information.
GDL 90 Installation Manual
CAUTION
560-1049-02 Rev. B
Installation Procedures
2-15