Short answer = call uAvionix & Trig, both
Longer answer = Skyfx appears to only output NMEA 0183 V4.1 + RAIM.
Trig TT22 installation manual indicates the following:
5.6.9 GPS Position Input
The GPS position input is required to support ADS-B functionality. The GPS
position input is an RS232 input to the transponder. The ADS-B features are
optional – no GPS is required for normal Mode S Elementary Surveillance.
The TT21/TT22 GPS input can recognise the following protocols:
· Industry standard “Aviation” protocol
· NMEA 0183 protocol ($GPRMC sentence is required)
· Freeflight and Accord NexNav GPS proprietary protocols
· Garmin ADS-B protocol, including ADS-B plus
· Trig ADS-B protocol
· C199 TABS compliant GPS using NMEA protocol
· Trig TN72 GPS protocol
The interface speed can be selected between 4800, 9600, 19200 and 38400
bps.
Some of the protocols listed above may not contain all the required data for a
compliant ADS-B message, depending on the intended airspace regulations.
For further information refer to Section 12 (ADS-B Compliance) of this
manual.
The questions you need to get answered by the two respective vendors are:
1) What information exactly is output by the Skyfx - does its output contain the $GPMRC sentence? Is this sufficient data to meet the US ADSB requirement? Or is this output data from the Skyfx in compliance with C199 TABS?
2) Does Trig have a different or updated way of stating their interface protocol requirements? Note their list does not specifically address Garmin's proprietary ADSB+ when in fact we know this protocol works with the TT22 to achieve FAA ADSB mandate requirements.