Com Discrete Inputs (Gtn 650 Only); Vor/Ils Audio (Gtn 650 Only) - Garmin GTN 635 Installation Manual

5.2.13 COM Discrete Inputs (GTN 650 Only)

COM MIC 1 KEY*
COM REMOTE TRANSFER*
COM REMOTE TUNE UP*
COM REMOTE TUNE DOWN*
An asterisk (*) following a signal name denotes that the signal is Active-Low, requiring a ground to
activate.
These inputs are considered active if either the voltage to ground is ≤3.5 VDC or the resistance to ground
is ≤375 . These inputs are considered inactive if the voltage to ground is 11-33 VDC or the resistance to
ground is >100kΩ.
5.2.13.1 COM MIC 1 KEY*
The COM MIC 1 KEY* discrete input, when pulled low, allows the audio that is present on the COM
MIC 1 AUDIO IN HI (P1003-5) to be transmitted over the radio.
5.2.13.2 COM REMOTE TRANSFER*
The COM REMOTE TRANSFER* discrete input may be used to flip-flop between the active and
standby COM frequencies. A momentary low on this pin will load the standby COM frequency into the
active COM frequency field.
The COM REMOTE TRANSFER* input may be used for emergency operation of the COM transmitter.
If the switch is depressed for two seconds, the active COM frequency changes to 121.500 MHz. Once the
emergency frequency is activated through COM REMOTE TRANSFER*, the GTN transceiver ignores
inputs from the front panel controls for COM selections only. The pilot may exit this independent
mode—restoring COM selection control to the front panel knobs and keys—by again depressing the
switch for two seconds.
5.2.13.3 COM REMOTE TUNE UP* (GTN 650 Only)
The COM REMOTE TUNE UP* discrete input may be used to scroll through a list of preset COM
frequencies. A momentary low on this pin will load the next preset frequency in the list into the standby
COM frequency field.
5.2.13.4 COM REMOTE TUNE DOWN* (GTN 650 Only)
The COM REMOTE TUNE DOWN* discrete input may be used to scroll through a list of preset COM
frequencies. A momentary low on this pin will load the previous preset frequency in the list into the
standby COM frequency field.

5.2.14 VOR/ILS Audio (GTN 650 Only)

500 VOR/LOC AUDIO OUT HI
500 VOR/LOC AUDIO OUT LO
500 VOR/LOC AUDIO OUT HI supplies 100 mW into a 500 load. It is a balanced output and the
500 VOR/LOC AUDIO OUT LO output must be connected.
Page 5-20
Rev. C
Pin Name
Pin Name
Connector
P1003
P1003
P1003
P1003
Connector Pin
P1004 16
P1004 17
GTN 625/635/650 TSO Installation Manual
Pin I/O
11 In
27 In
28 In
29 In
I/O
Out
Out
190-01004-02