FX -> TRIG TT21/22

Follow these steps to connect your FX device to a TRIG TT21/22 Transponder. Special thanks to Danny at Mendelssohns Pilot Supplies for providing pre-made cables, which can be purchased to simplify this connection. Mendelssohn Pilot Supplies.

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Step 1: Prepare the FX Pinout
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Refer to the FX pinout diagram:

1. Ground Pin: Choose any of the ground pins (4, 7, or 8).
2. Data Transmit Pin: Use pin 5, which transmits the serial data to the TRIG transponder.

Step 2: Insert Ground Wire

Insert the male D-Sub pin from the ground wire of the FX device into any ground pin hole on the 25-way D-type connector of the TRIG transponder. Possible options include:

• Pin 1: Ground
• Pin 4: Ground
• Pin 6: Ground
• Pin 10: Ground
• Pin 12: Ground
• Pin 14: Ground

Pin options have been taken from the "TT21/TT22 Mode S Transponder Installation Manual - 22 September 2017"
https://www.trig-avionics.com/library/00560-00%20AQ%20TT21TT22%20Installation%20Manual.pdf

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Step 3: Insert Data Transmit Wire

Insert the male D-Sub pin from the data transmit wire of the FX device into the GPS Position In pin hole on the 25-way D-type connector of the TRIG transponder:

• Pin 5: GPS Position In (Input)

Pin options have been taken from the "TT21/TT22 Mode S Transponder Installation Manual - 22 September 2017"
https://www.trig-avionics.com/library/00560-00%20AQ%20TT21TT22%20Installation%20Manual.pdf

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Step 4: Configure FX Settings

In this example, we're using 19200 baud with Automatic RS232 protocol. (TRIG can also be selected for pure GPS NMEA messages and no Traffic)

1. Power on the FX device.
2. Connect to the FX device via Wi-Fi and navigate to the FX interface at 192.168.1.1.
3. Go to the Settings page.
4. Under Advanced Settings, set the RS232 protocol to “Automatic”.
5. Select an appropriate baud rate for the TRIG transponder. The interface speed can be selected between 4800, 9600, 19200, and 38400 bps. If using in combination with another display, ensure the baud rate matches that of the other systems.

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Step 5: Configure Dynon SkyView Settings

1. Power on the TRIG transponder whilst holding down the FN button while switching on the transponder to enter setup mode.
2. Navigate to the GPS Input setting in the configuration menu.
3. Select the NMEA 0183 protocol.
4. Set the line speed to match the FX device setting (In this case 19200 baud).

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Step 6: Verify Data Transmission

1. Ensure the FX device has a GPS lock.
2. Once locked, the FX device will start streaming NMEA data to the TRIG transponder.
3. Verify that valid GPS position data is being received by the TRIG transponder.
4. The position data from the FX device should be reflected in the transponder’s ADS-B position reports.

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Conclusion

By following these steps, you will successfully connect your FX device to the TRIG TT21/TT22 transponder, enabling GPS position reporting for ADS-B functionality.

For additional support or to purchase pre-made cables, please visit Mendelssohns Pilot Supplies.

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