Why does VoxATC think I'm 300 feet lower?

[Hans Hartvelt 11]

John, thank you for replying. Although you're also using Active Sky, I'm not convinced that the cooperation between AS and VoxATC is flawless. I will do some testing, since I have restored my PC to an earlier date and uninstalled / reinstalled P3D 4.5. I will let you (and Thomas) know.

[Hans Hartvelt 11]

Hi guys,

I made a test flight in a high pressure area. From Budapest (LHBP, 1026 HpA) to Belgrade (LYBE, 1026 HpA). Enroute cruise level 190. I didn't get wrong altitudes from the controllers because they stated that I was on the Gazda1J departure or on the Tisak1F arrival. That was strange too, because I had completed the SID already for many miles.

I had the sim info at the screen (Shift+Z). Until transition level (10.000 feet) the sim info, the PFD and the SBY altimeter gave the same altitude. When I switched to STD at 10.000 feet, the sim info was diverting from the other ones. At cruise level, the PFD read 19.000 feet, the SBY altimeter read 19.000 feet also, but the sim info line read 19.341 feet. So P3D remains counting in QNH altitudes. Probably VoxATC retrieves its info from P3D and therefore it is not strange that it gives the wrong altitude. It seems to me that VoxATC is not to blame for this, but maybe Prosim737 isn't cooperating well with P3D.

Do you agree or other suggestions?

[vadriver 248]

5 hours ago, Hans Hartvelt said:

other suggestions?

hans

have you reviewed Vox's flight log ...... your aircraft's position is regularly seen.

[Hans Hartvelt 11]

 

 

19 hours ago, vadriver said:

hans

have you reviewed Vox's flight log ...... your aircraft's position is regularly seen.

Thanks for the tip, but NO. I didn't have logging enabled. So today I made the same flight as yesterday again. But first I enabled logging and saved log. This time QNH at the departure airport has lowered to 1023. At the arrival airport QNH was still 1026. At cruise level PFD read 19.000. and the sim 19.272. VoxATC made contact with Belgrade Center stating that my altitude was FL 194. So 3 different altitudes, which should be the same.

I cannot find a flight log. The info about logging in the manual is not more than 1 line. Please inform me where I can find it. I could find an error log, but the lines in this log are abracadabra for a simple captain like me (see below). Moreover, the date of the log is 26th of november, whereas today is 27th of November.

Log Start 11/26/2020 14:16:02

$$$$ Thread time overun : 
   at System.Environment.GetStackTrace(Exception e, Boolean needFileInfo)
   at System.Environment.get_StackTrace()
   at com.intworkings.voxatc.ThreadCheck.Sleep(Int32 milliSecs)
   at com.intworkings.voxatc.FSUIPCInt.ProcessSimconMessages()
   at System.Runtime.Remoting.Messaging.StackBuilderSink._PrivateProcessMessage(IntPtr md, Object[] args, Object server, Object[]& outArgs)
   at System.Runtime.Remoting.Messaging.StackBuilderSink.AsyncProcessMessage(IMessage msg, IMessageSink replySink)
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem()
   at System.Threading.ThreadPoolWorkQueue.Dispatch()
User data update stalled at 11728797
User data update unstalled at 12025890
User data update stalled at 12040984
User data update unstalled at 13067469
User data update stalled at 13183203
User data update unstalled at 13349250
User data update stalled at 13993406
User data update unstalled at 14013531
User data update stalled at 17148155

At the end things got wrong because VoxATC didn't understand my message' runway vacated' and urged me continously to pass my message.

[vadriver 248]

5 hours ago, Hans Hartvelt said:

where I can find it.

C:\Users\...........\AppData\Roaming\Internal Workings\VoxATC ......\Err.log

[Hans Hartvelt 11]

John, thanks, I found it.

And it is very impressive. I've got an insight what VoxATC is doing behind the screens. The part about my test flight is 8135 lines long. But most of them are related to AI aircraft. So I learned that when I want to make a log file, I must set the AI aircraft at 0%.

These are the most important lines:
14:40:26.6601392 Current Position = 46.1051515183344 19.7524726234119 19280.8981562262
5756187 Prompt Text set :  belgrade center  klm one seventy four  with you at flight level one niner four

So we see 2 problems.
Problem 1: VoxATC prompts flight level 194 whereas the altitude is 19.280 feet.
Problem 2: When reaching transition level (in this case 10.000 feet), I set my altimeter at STD using the BAR knob at my CPFlight EFIS737. It is reflected in the PFD, but it doesn't effect P3D which remains counting in QNH altitudes. Apparently VoxATC retrieves the altitude info from P3D. So big question: Who is to blame for this anomaly: P3D, Prosim737 or VoxATC?

[vadriver 248]

8 hours ago, Hans Hartvelt said:

Who is to blame for this anomaly

Hans

To answer, you need to know the area QNH at that position ....... 1022 or 1026mb ??

[Hans Hartvelt 11]

John, thanks again for replying, but IMO the local QNH is not relevant. My flight level is 190 and this is the altitude that VoxATC should prompt and not 194. I understand that VoxATC retrieves its altitude info from the sim and not from any other third party add-on. I think that Prosim doesn't communicate the switch to STD QNH to P3D. Therefore I have put a post on the Prosim B737 forum about this issue. When I receive an answer I will copy it on this forum.

[vadriver 248]

6 hours ago, Hans Hartvelt said:

STD QNH

aka QNE .....

[Hans Hartvelt 11]

Hi guys, I'm back from van my consultation round in the Prosim community. And this is what I learned.

The config page of Prosim MCP has an option 'captain QNH controls FS QNH'. If you want P3D to follow your altimeter settings, than you must check this option. I hadn't checked this option.

Pete Dowson tipped me about a way to show the current QNH of P3D. Open FSUIPC. Go to the logging tab, right side. Type 0330 in the Offset box. Select U16 from the drop down menu in the Type box. Select how you want to display the value. I have choosen for a window in FS (P3D). Then you must divide the shown value by 16 to get the QNH value > 16210 / 16 = 1013.125. When I turn the BARO knob at my EFIS (or press for STD), I see the value change. This is the ultimate proof that P3D follows my settings.

The red info line gives the altitude above MSL, based on 1013 hPa. This value is not influenced by any setting in P3D. So when flying above transition altitude (STD set) there will also be a difference between the altitude displayed in this info line and the altimeter in the PFD or the SBY altimeter. Nothing to worry about, this is intented. The position in the VoxATC log file is also retrieved from this info line. Therefore it is not strange that the position in the log file gives an altitude of 19376 while my PFD / SBY altimeter gives an altitude of 19000 (flight level 190).

My original question was: Why states VoxATC that I am flying at FL 194 (or 187 > 300 feet lower) whereas I am flying at FL 190? I hope that this problem will be resolved after my enabling of the option in Prosim MCP. But I am not so sure after a first test. I made a flight from Dublin International (QNH 984) to London Heathrow (QNH 981), cruise level 210. Handover to Manchester Center:
Red line: 20185
PFD / SBY altimeter: 21000
VoxATC text prompt: FL 211.

So not exactly right. I will keep testing and let you know when I have new info.

PS I made nice screen shots, but it's a hell of a job to get them in this post. So I did'nt.