Garmin GTN 625, Installation Manual

Page: 105 / 254

190-01004-02 GTN 625/635/650 TSO Installation Manual
Rev. F Page 5-25
5.2.13 COM Discrete Inputs (GTN 650 Only)
An asterisk (*) following a signal name denotes that the signal is an 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 >100k Ω .
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 supplies 100 mW into a 500

load. It is a balanced output and the
500

VOR/LOC AUDIO OUT LO output must be connected.
Pin Name Connector Pin I/O
COM MIC 1 KEY* P1003 11 In
COM REMOTE TRANSFER* P1003 27 In
COM REMOTE TUNE UP* P1003 28 In
COM REMOTE TUNE DOWN* P1003 29 In
Pin Name Connector Pin I/O
500

VOR/LOC AUDIO OUT HI P1004 16 Out
500

VOR/LOC AUDIO OUT LO P1004 17 Out