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Pressure Baro 100% fail. ECHO. Screen shots

charosenz

Well Known Member
I got a warning letter from the FAA that my ADSB has a 100% failure for the pressure alt. I had not previously done a PARP report.

I adjusted the sensitivity from 1300 all the way down to 1000. Still no change. I have contacted Uavionix support and the only thing they suggest is to try a higher sensitivity setting.

I am attaching screen shots from my Echo APP in hopes someone can spot something that I can work with.

I have a Garmin 320A Xpnder and a ACk encoder.

Thanks.
 

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  • ECHO app screen shot of data report.jpg
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  • ECHO app screen shot of data report page2.jpg
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  • PAPR_20220901_A38A48_494034665.pdf
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That right there is why I removed one of these devices. Why they didn't or wouldn't allow for hardwired serial altitude encoder, I'll never know.
 
Hard wired ADSB to xpnder

I am no expert on electonics but from what I read in the manual you can wire the ADSB directly if you want. Or allow it to "sniff" (grey wire?) it instead too. Here are two screen shots showing either method.
 

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  • Transponder Echo hard wire schematic.jpg
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  • transponder Echo grey wired sniffer mode.jpg
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Step 1: Confirm that your 320A transponder is actually working. Check for dirt build up around the base of the transponder antenna, call and ask ATC if they see your transponder. Or, if you're near the 2 year test anyway, ask the pitot-static/transponder check guy if the transponder is okay.

Also agree with others, hard-wired is the way to go. While this "listen on the wiring for signals that, ideally, shouldn't be there" system apparently works, but relying on a system to never be perfect just seems wrong....

Also, if you are flying in an area with no radar coverage (nothing to 'ping' your transponder) that may be another reason for the negative report.

Finally, get this fixed. I think you were supposed to have gotten a 'no problems' report right after you installed the ADSB-out system.
 
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I have installed 3 Echo systems, all with the sniffing option. They work flawlessly. However, I made sure I had a good encoder talking to a digital transponder. Your 320A is a digital transponder with analog face plate so that should be no problem. Also, all 3 systems I installed used the SkyFyX Ext GPS receiver package.

Your analog ACK encoder could also be part of the problem. Do you have any other altitude source like a small EFIS, G5 or digital flight deck with ADAHRS? If so you could switch altitude source over to one of those digital systems.

Also, it sounds like your system was not properly tested prior to release. You or whomever installed the system should have gotten a clean PAPR report and made a log book entry stating as much. The FAA has very specific language to be used in the log. The mere fact you have never had a PAPR report prior to the FAA nanny computer seeking you out is telling.
 
I consider myself pretty good with EchoUAT. You definitely are not getting altitude data from your transponder/encoder. The sensitivity could still be the issue. You can’t damage anything by rolling it down….Id take it to 600. Re-evaluate what the monitor page shows you for PRESSURE ALTITUDE. You should be able to see this sitting on ground. If no better, do as Jim recommended, go fly and call center or approach for a simple transponder check. If they see you, inquire as to how they see you ADSB data. Either Bad encoder/transponder or sensitivity. If no one can see you, go for 2yr vfr transponder check. I’m betting on sensitivity…holding thumbs.
 
Serial connection actually preferred

That right there is why I removed one of these devices. Why they didn't or wouldn't allow for hardwired serial altitude encoder, I'll never know.

The Echo UAT has two serial ports. One is used to input the WAAS GPS NMEA data from either it's own antenna (SkyFX) or from a certified WAAS source you may already have (GNS 480, GNS 430/530, etc). Use the 115200 baud rate for the SkyFX or the highest rate your WAAS transceiver will allow on the RX side. The TX can be used to send ADSB weather and traffic to an EFIS in GDL 90 format. You can use the other serial port RX to take the altitude data (usually Icarus format but check the instructions) from any digital transponder. It works just great this way.
 
The GTX320 cannot output serial data.
Unless you have an ACK mod 9 it can't output serial date ether.
So, you're probably stuck with 'sniffing'.
Seen lots of 320's that don't work well/out of spec so that's a good place to start.
 
We just troubleshot a similar failure in our EchoUAT. We didn't build it, but at some point someone decided buttsplices and ungrounded shielding were the order of the day. This resulted in at-first intermittent, then total failure of pressure altitude being sent to the GTX 327 Transponder, therefore BAlt failed the same.
 
Had a similar problem with my echoUAT and was told that factory says reset Transponder Threshold to 1350 on all units effective, I believe, in 2020. Use the ECHO App download from store to configure and monitor the echo output.
 
Baro Alt on Parp

Based on how I read the PAPR report (which is attached at the top of this thread) all categories had very good performance - except the Baro Alt. Which in my belief all points to the encoder or al least to a problem with the communication between it and the Xpnder.

I have tried adjusting the sensitivity from 1350 down to 1100 with nothing reporting on the Echo APP. I have not yet increased it higher than 1350 which is what Uavionix tech wants me to do. If that fails then I plan to crawl under the panel to remove and inspect the encoder.

One person asked if I had any other digital altitude device I could use and unfortunately I do not. I have a Stratux but my understanding is this will not work as a source for the ADSB out.
 
I consider myself pretty good with EchoUAT. You definitely are not getting altitude data from your transponder/encoder. The sensitivity could still be the issue. You can’t damage anything by rolling it down….Id take it to 600. Re-evaluate what the monitor page shows you for PRESSURE ALTITUDE. You should be able to see this sitting on ground. If no better, do as Jim recommended, go fly and call center or approach for a simple transponder check. If they see you, inquire as to how they see you ADSB data. Either Bad encoder/transponder or sensitivity. If no one can see you, go for 2yr vfr transponder check. I’m betting on sensitivity…holding thumbs.

Butch,

I appreciate the info. I will try some more aggressive sensitivity settings Both up and down as so as we get out of -9F weather.
 
One person asked if I had any other digital altitude device I could use and unfortunately I do not. I have a Stratux but my understanding is this will not work as a source for the ADSB out.

The rules require that you use the same ‘altitude device’ (encoder) for both the transponder and adsb-out.
 
Sensitivity settings

I finally got around to adjusting the Threshold values. I went down to 800 at 50 increments and still no baro values in the Echo App. I also went up to 1600.

I am left to believe my very old encoder is just not working. I did check the wiring and it is all solid and I have both good power and ground to it.

So I have ordered a new encoder.

I also learned that my 320A Garmin Transponder does not have an input for serial data (on pin 20) like the 327 does. (Although I wonder if this functionality is possibly on pin 20 but just not advertised?)

So my plan once I get the new encoder is to wire the serial data directly to the UAvionics Echo pin4. (Their support said this should be fine).

Comments welcome....
 
To echo Bob... The encoder send Baro Alt data to the transponder which transmits it to ATC. So if ATC is reading your altitude, the encoder is working.

Separate from this... If the ADS-B OUT has Baro Alt failure then your ADS-B OUT device is not getting good Baro Alt data from your working encoder. If the encoder is hard wired to your ADS-B OUT device, then something is wrong with the wiring. If your ADS-B OUT device "sniffs" the Baro Alt data, then something is wrong with the "sniffing".
 
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I am having the same failure on my PAPR ("Missing Elements - BAlt - 100%" as well as "Other Checks - Mode 3A - 100%"). From reading this, I'm assuming an encoder failure or a communication failure between encoder and Echo. I'm going to check with ATC today to see if they see my mode C altitude.

Can anyone tell me where I might find the echo serial number, the ssid number, and the current firmware version? Uavionix is requiring this information in order to submit a ticket. I checked my installation documentation in my logbook but don't find the info there. I cannot find it on the app either.
 
I am having the same failure on my PAPR ("Missing Elements - BAlt - 100%" as well as "Other Checks - Mode 3A - 100%"). From reading this, I'm assuming an encoder failure or a communication failure between encoder and Echo. I'm going to check with ATC today to see if they see my mode C altitude.

Can anyone tell me where I might find the echo serial number, the ssid number, and the current firmware version? Uavionix is requiring this information in order to submit a ticket. I checked my installation documentation in my logbook but don't find the info there. I cannot find it on the app either.

Jim,

The serial will be on the receipt. I can't remember if it is also printed on the echo itself. The SSID will be seen as the name of the wifi signal it is producing, so if you were to look at the wifi signal on a phone or PC it would show up as PINGXXXX. I cannot say where the software version is. I did not need to include that with my repair ticket.

Yes, it is impossible to tell if the baro failure is the encoder itself, or the wiring connection without isolating one or both.

I should have my new encoder by Weds. I will end up having an extra harness which I could send to you for testing (depending on what Transponder you have). It is a bit unlikely to be the cause of your issue, but nothing ventured nothing gained.

Did you get a clear PAPR report in the past, or is this a new issue?

Good luck to you.
 
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Jim,

The serial will be on the receipt. I can't remember if it is also printed on the echo itself. The SSID will be seen as the name of the wifi signal it is producing, so if you were to look at the wifi signal on a phone or PC it would show up as PINGXXXX. I cannot say where the software version is. I did not need to include that with my repair ticket.

Yes, it is impossible to tell if the baro failure is the encoder itself, or the wiring connection without isolating one or both.

I should have my new encoder by Weds. I will end up having an extra harness which I could send to you for testing (depending on what Transponder you have). It is a bit unlikely to be the cause of your issue, but nothing ventured nothing gained.

Did you get a clear PAPR report in the past, or is this a new issue?

Good luck to you.

Thanks for the offer, Charlie. This was my first PAPR. The unit had been configured for a hard wired connection, but that was not working at all (not generating any PAPR). I will check what I can for now and try to communicate with uAvionix. I'll post back here when I get more info.
 
Echo Uat serial number

I never found the serial number using the App.


I did find a small square sticker on the case that said "sn" on it, and "uavionics.com", and "ping"


If it is mounted in a hard to access area this may help to locate that label
My label was located as follows.
1 the multipin connector was pointing skyward.
2) the black side with the word echo" was facing aft, and "echo" was upside down.
3) the label was on the silver side, facing port, the side near the "o" in "echo"

Needed a dental mirror, and cellphone camera to see it, luckily mine is a tip up...
Chuck
 
So, I sent in the ticket request without the serial number, and uAvionix got right back to me. They advised the transponder threshold should be at 1350. Mine was at 1550. I reset it, and my PAPR report today was all good.
 
Had a similar problem with my echoUAT and was told that factory says reset Transponder Threshold to 1350 on all units effective, I believe, in 2020. Use the ECHO App download from store to configure and monitor the echo output.

So, I sent in the ticket request without the serial number, and uAvionix got right back to me. They advised the transponder threshold should be at 1350. Mine was at 1550. I reset it, and my PAPR report today was all good.
my53cad FTW!
 
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