Sandia STX165R Quick start guide

Connecting and configuring the Sandia STX165R
transponder to the MGL iEFIS syste
Please refer to the Sandia Aerospace website for the installation manual. Please take heed of
RF and antenna installation requirements. Ensure that RF cable losses are within specified
limits.
This document specifies how to connect and configure the transponder to work with an M L
iEFIS.
The transponder has two D-type connectors. The D-15 is used as parallel altimeter encoder
input. This connector is NOT used with the M L installation and must remain unused.
You will only need to connect the D-9 connector. You will supply power and at least two wires
to connect to your chosen serial port on the iBOX of the M L EFIS system.
This image shows the required connections (also refer to the Sandia installation manual).
Pin 1 - Avionics power supply, typically 12V (thick red wire in this image)
Pin 2 - connect this to the RS232 transmitter (TX) on the iBOX

Pin 3 - RS232 ground. See note below
Pin 5 - Avionics power supply ground
Pin 7 - Connect this to the RS232 receiver (RX) on the iBOX
Note on RS232 ground
In most installations your EFIS and your transponder would be connected to the same ground
point. In this case, do not connect the RS232 ground on both sides as this will create a
ground loop and could potentially cause damage should your transponder loose its own
power supply ground (for example a cable break).
You may connect the ground (either from the iBOX side or the transponder side) to the shield
of the RS232 cable as is shown in this image. Do not connect the shield on both sides.
If your EFIS and transponder are not connected to the same power supply or if you are using
an Avio uard isolated power conditioning system on the EFIS or transponder side only (in
this case we have two separate supplies and the grounds are not connected), you need to
connect the RS232 ground between the two systems.
Avoid using then cable shield as ground connection – use an inner core for this (so you need
a three core shielded cable). The shield should only be connected on one side for maximum
effect.
EFIS setup
Select the above in your System setup -> Transponder setup
Enter the VFR code for your region. If you have an ADSB-out system connected to the EFIS,
you can select to slave the two to each other. In this case sqauwk codes and ident will be
mirrored on each device.

Select the serial port that you have connected the Sandia transponder to. For this example
we have chosen port 5. The relevant pins on the iBOX are marked T5 and R5 for TX and RX.
After you have selected the serial port, please restart your system to enable the new settings.
Using the transponder
Tap on the small transponder status display on the top to bring up the transponder control.
Tap the ID icon to activate the ID when directed by ATC to do so.
Tap the V icon to select your standard VFR code into the transponder.
Tap the MD icon to select the transponder operating mode.
Note: “ON” = transponder active in mode A (altitude is not transmitted)
“ALT” = transponder active in mode C (altitude will be transmitted)
Use the numeric icons to tap in the desired transponder squawk code.
Tap “C” to cancel and re-enter the code. Partially entered codes are not activated, you must
enter 4 digits.
Tap “X” to close the transponder control.