Author Topic: Seeing PAW and ADSB from same plane  (Read 4316 times)

Gary Nelson

Seeing PAW and ADSB from same plane
« on: August 19, 2018, 06:58:06 am »
On an impromptu 6 x fixed-wing microlight fly-out on Friday, myself and one other had PAW and ADSB out installed. We both use it via Sky Demon. The problem was I was seeing two of him, almost superimposed on top of each other and each with his same call sign. It would seem I am therefore receiving his PAW and ADSB as two separate planes? Thoughts on what one (or both) of us need to do?

Ian Melville

Re: Seeing PAW and ADSB from same plane
« Reply #1 on: August 19, 2018, 08:19:37 am »
That would suggest that the hex code is incorrect in either his transponder or his PAW
If you can supply your log file we can check that out?

exfirepro

Re: Seeing PAW and ADSB from same plane
« Reply #2 on: August 19, 2018, 01:54:45 pm »
Gary,

An interesting one.

At first glance, I agree with Ian - and a check to ensure your colleague has the correct ICAO Hex for their aircraft in both PAW/Rosetta and Transponder would be my first ‘Go to’. I have seen several cases of a finger-induced error here - often involving two figures being typed in the wrong order. Very easy to do so check carefully.

The fact that you say both aircraft symbols are showing the same ‘Callsign’ (by which I presume you mean ‘Aircraft Reg’) is, however, confusing me - as the Aircraft Reg is normally determined by PilotAware by looking up the received ‘Hex’ in an embedded table. The same ‘Aircraft Reg’, would therefore imply that both PAW and Transponder are transmitting the same Hex - which should result in one ‘aircraft’ being automatically filtered out by PilotAware. This effect could however perhaps still be explained if the aircraft Reg was in your colleague’s PAW Hex ID box instead of the ICAO Hex ID box. If in any doubt, can you please take and post a screen grab of their ‘Configure’ Screen.

The altitude difference BTW is easily explained due to allowable variation between the two transmitting devices, though you would of course normally only ever see one.

Let us know what you find.

Best Regards

Peter

Ian Melville

Re: Seeing PAW and ADSB from same plane
« Reply #3 on: August 19, 2018, 11:36:01 pm »
Pete, I don't see where Gary mentioned altitude, has the OP been edited?

Apart from tolerances, you can also get an altitude difference due to the transponder being linked to the static system and the PAW using cabin pressure as the static.

Cheers
Ian

exfirepro

Re: Seeing PAW and ADSB from same plane
« Reply #4 on: August 20, 2018, 10:35:28 am »
Hi Ian,

Apologies... Probably prompted by Gary saying...  ‘almost superimposed on top of each other’  ....which must (at least in my head) have implied an altitude difference.

You are of course correct about cabin vs static pressure. I tend to forget about that one - not having a ‘cabin’.

Best Regards

Peter


Gary Nelson

Re: Seeing PAW and ADSB from same plane
« Reply #5 on: August 27, 2018, 11:33:00 pm »
I’ve asked the other pilot to check his Hex is the same on his PAW and ADSB and will report back once I hear from him.

exfirepro

Re: Seeing PAW and ADSB from same plane
« Reply #6 on: August 28, 2018, 09:56:02 am »
Thanks Gary,

I have seen this several times. Usually a finger induced error when programming the PAW, e.g. xx12yz accidentally entered as xx21yz, though on one occasion it was wrong in the Transponder!

Best Regards

Peter

Gary Nelson

Re: Seeing PAW and ADSB from same plane
« Reply #7 on: August 29, 2018, 01:02:58 am »
Ok problem solved in that the other pilot did have different Hex codes and he has now corrected it. I checked this on my Sky Demon and indeed now showing him without the duplicate. However, he thinks a PAW upgrade may have reset the Hex code, as he was confident he had put the correct one in both his transponder and PAW?

 

exfirepro

Re: Seeing PAW and ADSB from same plane
« Reply #8 on: August 29, 2018, 09:30:14 am »
Hi Gary,

Thanks for the update. Glad you have found the cause. PAW updates ‘shouldn’t’ upset previous settings provided they have been correctly saved, as this creates a ‘Profile’ - (see the Profiles button at the bottom of the Config page). Not saying it didn’t happen though as I have occasionally come across this sort of issue in some of the older software versions. That’s why we always advise keeping your software updated.

Good to hear it’s sorted though.

Best Regards

Peter

Paul_Sengupta

Re: Seeing PAW and ADSB from same plane
« Reply #9 on: September 03, 2018, 04:37:00 pm »
There was an issue someone reported on here either in the current software or the software before, where saving profiles didn't work entirely correctly, and the hex ID for the first profile got reset? Something like that. So if he's saved a profile and loaded that in, it might have caused issues. I'm guessing this has been corrected now, but I haven't looked it up!

exfirepro

Re: Seeing PAW and ADSB from same plane
« Reply #10 on: September 04, 2018, 04:30:23 am »
Paul/Gary,

I found a problem with profiles reverting to the ‘default’ ‘MAC-based’ Hex code some time back in a previous (possibly pre-release Engineering) Software build, but it was definitely fixed at the time.

Worth checking your mate has the latest 20180520 version Gary, just in case.

Regards

Peter