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ADS-B SIL / SDA failure

BruceMe

Well Known Member
ADS-B SIL / SDA failure (solved)

I've installed a GPS 20A with my GTX 23ES via the Serial 2 receive pin (serial 1 was already being used by the old G3X). The GPS 20A is also the GPS source for my G3X via CAN. It appears to be operating well, but my ADS-B report is stating I have total failure of all SIL and SDA.

I believe the 20A / GTX 23ES is a valid combination, so I'm not sure why the SIL/SDA is failing. Is this just a bad software configuration on something that I can fix with dials? Before I tare into my panel again, should I move this to serial 1 on GTX 23ES? This takes about an hour.

-Bruce
 
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Bruce, here's a long shot on a Saturday night: did you reset your configuration page for the GTX 23ES on your G3X? Check to make sure integrity is set to 1E-7. I'm assuming this is your first install of the GPS 20A for ADS-B out purposes, in which case you probably had a different integrity setting. Serial port sequence should not be a problem.
 
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I've installed a GPS 20A with my GTX 23ES via the Serial 2 receive pin (serial 1 was already being used by the old G3X). The GPS 20A is also the GPS source for my G3X via CAN. It appears to be operating well, but my ADS-B report is stating I have total failure of all SIL and SDA.

I believe the 20A / GTX 23ES is a valid combination, so I'm not sure why the SIL/SDA is failing. Is this just a bad software configuration on something that I can fix with dials? Before I tare into my panel again, should I move this to serial 1 on GTX 23ES? This takes about an hour.

-Bruce
Hello Bruce,

As shown on page 27-28 of the current Rev. AK G3X/G3X Touch Installation Manual, the GPS 20A must be wired to RS-232 IN 2 on the GTX 23ES, so your wiring should be correct.

As explained on page 34-115, the Position Integrity must be set to "1E-7" as Pat explained. We suspect that yours is still set to "VFR GPS".

Position Integrity: This selection is only available for GTX 23 ES and GTX 33ES units. Refers to the integrity level of the separate TSO WAAS GPS input that can be connected to the transponder. Set to 1E-7 when a certified GNS/GTN/GPS unit or GPS 20A is providing ADS-B Out+ to the transponder. Set to "VFR GPS" if none of these devices (certified GNS/GTN/GPS unit or GPS 20A) are connected to the transponder.​

Contact us if you have further questions.

Thanks,
Steve
 
down side of being amateur... we screw up and miss the obvious... at least I do sometimes
 
You'll be fine. I have the GPS20A / GTX23ES combination, works great - passed the FAA flight check the first time (although this was several years ago when it was done via email with a real person...)
 
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FINALLY! I did the TXPD config and flew. I have a clean report.

Thank you all!

-Bruce
 
FINALLY! I did the TXPD config and flew. I have a clean report.

Thank you all!

-Bruce
Hello Bruce

That is great news. Thanks for letting us know.

You have really good ADS-B Out equipment that will knock out perfect reports all day, every day.

Thanks,
Steve
 
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