W&W Trig TT21 Installation Instructions

W&WTrig TT21 or TT22 transponder installation instructions
READ ALL INSTRUCTIONS BEFORE INSTALLING THIS HARNESS.
1) Install the 25 pin connector marked 'TT 22' to the transponder and tighten the two
mounting screws.
2) Install the 9 socket connector marked 'TC 20' to the control head and tighten the two
mounting screws.
3) Route the twisted pair of wires marked 'TT22 GROUND' to an avionics ground point.
The ground connection may be made by soldering or by installing a ring terminal and
securing it to a ground stud.
4) Route the wire marked 'TT22 POWER' to a 3 Amp circuit breaker or fuse and secure
as required.
5) *Optional* If pressure altitude information is needed for another unit (i.e. a GPS),
serial altitude data is available from the wire marked 'SERIAL ALTITUDE OUT' at the 9
socket connector, at the control panel. Connect the data 'In' wire from your unit to the #1
pin of the 2 pin connector. Connect the data 'Ground' from your unit to the #2 pin.
6) *Optional* The following functions, if desired, are connected through the 4 socket
connector located at the 25 pin connector marked 'TT 22'. Use the 4 pin connector in
your harness kit.
a) If connecting traffic information system to another unit, connect the TIS input wire
to the #1 pin. Connect the TIS input ground to the #3 pin.
b) If an external standby switch is to be used, connect a customer provided switch to
the #2 pin. When the switch connects to ground, the transponder will be placed in the
'Standby' mode.
c) If an external ident switch is to be used, connect a customer provided, momentary,
switch to the #4 pin. When the switch connects to ground, the transponder will transmit
the identification code.
7) *Optional* If RS232, GPS data in is desired, use the 3 pin connector on the 25 pin
connector marked 'TT 22'. Connect the RS232 TX line from the GPS to the #1 pin.
Connect RS232 signal ground to the #3 pin. Note that the #2 pin is not used on this
installation.
8) *Optional* If a squat switch input is to be used to automatically switch from ground
mode to air mode, or to control the flight timer, connect the wire marked 'TT22 SQUAT
SWITCH' to a customer provided switch. Program to activate on low, or high, as
needed.