Author Topic: FMC company route file format for simulators  (Read 12834 times)

Offline Hardy

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FMC company route file format for simulators
« on: June 27, 2012, 09:32:25 AM »
Hi there.

If I may, here's a technical question for Christian or -- I understand he's very busy -- for anyone familiar with TOPCAT/PFPX generated FMC company route files for use in simulators etc.

Now, for example, every MSFS add-on has its individual FMC route file format, and TOPCAT/PFPX internally uses individual data converters to output FMC route files for each product, correct?

Is there also any TOPCAT/PFPX standard format, a format that new simulators can use?

I'm developing Precision Simulator 10 (PSX) with a new FMC model, so I'm flexible and open to any existing file format. Instead of asking TOPCAT/PFPX to make yet another special file output, I want PSX to read the TOPCAT/PFPX standard output directly -- if it exists.

Well, if such a standard exists, what data does it include?

I see at least three possible file format variants:



Variant #1
 
A simple route description without coords:
E.g. DIRECT JFK J77 ORD J88 LAX DIRECT SFO
PSX could read these identifiers and then get all airway waypoints and coords from PSX's internal database (PSX has its own world-wide nav database). However, the input data would have to include the 2-letter ICAO regions of each airway, and also that of the waypoints if they are DIRECTs, and these would also have to include the waypoint type (VOR, DME, NDB etc.) as multiple waypoints of the same name may exist.


Variant #2

A route description with identifiers of airways and waypoints and the coords of each waypoint. SIDs, STARs, approaches not included.


Variant #3

A route description with identifiers of airways and waypoints and the coords of each waypoint, including conditional waypoints of SIDs, STARs, approaches. This, however, would require additional data such as path terminator, curve radius etc. of each conditional waypoint.



I guess #1 has too many disadvantages (risk of database mismatch; and additional region and type data required). So, to get back to my original question: Does TOPCAT/PFPX have any universal company route format, and if so, is there a description of it for developers who want to inject those company routes into their FMC simulations?


Thanks!


Best wishes,

|-|ardy
« Last Edit: June 27, 2012, 09:35:11 AM by Hardy »

Offline Christian Grill (TOPCAT)

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Re: FMC company route file format for simulators
« Reply #1 on: July 05, 2012, 07:20:48 PM »
Hi Hardy,

Variant #2 matches the PFPX route format.
I've attached a sample route - the format should be pretty self-explaining...
Best Regards
Christian Grill
TOPCAT

Offline Hardy

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Re: FMC company route file format for simulators
« Reply #2 on: July 22, 2012, 09:44:40 PM »
Thank you, Christian. This helps, it's pretty self-explanatory.

Are there any plans to add cost index and initial cruise altitude to the output file? Normally, these may be stored in FMC company route files also, if available.

Can PFPX also output wind and OAT data for each waypoint? These data could be sent into the FMC using an ACARS simulation.


Cheers,

|-|ardy


P.S.: Is the company flight number stored somewhere?


« Last Edit: July 23, 2012, 12:43:01 AM by Hardy »

Offline Hardy

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Re: FMC company route file format for simulators
« Reply #3 on: December 22, 2012, 12:16:42 PM »
Good morning,

regarding the above sample route file:

This line, for example:

WPT SONEX   0SONEXEGE0 EGSONEX                         035950     +53488633-002168766+0000000000EGTT


These are the coords, obviously:

+53488633
-002168766


Could somebody on this forum confirm that the format is degrees and fractions of a degree? No minutes, no seconds, just degrees and fractions of a degree, right?


+53488633 represents 53 north plus 0.3488633 north -- In other words: N53.488633

-002168766 represents 002 west plus 0.168766 west -- In other words: W002.168766

(I'm writing it here at great length just to be sure there are no hidden minutes or seconds.)

Thank you!

Let's not disturb busy Christian :-) Maybe someone else knows the answer as well.


Cheers,

|-|ardy








Offline Pierre95

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Re: FMC company route file format for simulators
« Reply #4 on: December 22, 2012, 12:44:33 PM »
Hi Hardy,

Yes,
Quote
+53488633
-002168766

Is Degrees and fraction or decimal degrees.

Hope This help.

Cheers
Pierre





Offline Hardy

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Re: FMC company route file format for simulators
« Reply #5 on: December 22, 2012, 09:24:03 PM »
Hi Pierre,

thank you.

I just rechecked the above route waypoints with my database and I think there is an error somewhere. I, too, am using data from EAG/Navtech (who supply Navigraph), but there's a significant difference between my coords and the coords in the above sample route.

Do you know if the values in that route are a conversion from the ARINC 424 format (degrees, minutes, seconds etc.)? If so, there might be a conversion error. The higher the fraction value, the greater the difference to my data. There is no error if the fraction is zero.

I cross-checked it with a navaid info site in the Internet*:

Example: BGR VORTAC in the USA, 114.80

PFPX:     N44836379 W068869293 (fractions of degree)
Internet: N44841800 W068873964 (fractions of degree)
Internet: N44503048 W068522627 (ARINC 424)
Navtech:  N44503046 W068522627 (ARINC 424)

This is minimal (a few millimeters):
N44503048
N44503046

But this is significant:
N44836379 W068869293
N44841800 W068873964


Cheers,

|-|ardy



* I can post the URL on request. I'm not including the URL right now because their advertising banner currently links to a "Ukrainian women" site (what a nonsense ad).

Offline Pierre95

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Re: FMC company route file format for simulators
« Reply #6 on: December 23, 2012, 07:51:12 AM »
Hi

Good explanation Fabian !

Seasons Greetings
Pierre

Offline Hardy

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Re: FMC company route file format for simulators
« Reply #7 on: December 23, 2012, 12:06:38 PM »
Thank you, Peter.

I agree with your reverse conversion method. However, I'm concerned about the initial conversion, vice versa, from ARINC to degrees/fraction of a degree.

I assume that the data Navigraph or PFPX use first come in in ARINC format (degrees, minutes, seconds, tenths of a second, hundredths of a second), and the database processor converts them to degrees/fraction of a degree. I, too, have to do this conversion in my simulation.

This initial conversion is not as trivial as the reverse conversion. I've made a mistake already myself. I noticed that my conversion didn't exactly agree with Jeppesen charts etc. But meanwhile they do agree. As far as runway threshold coords are concerned, they also seem to agree with MSFS and X-Plane runways.

I'll check again ...


Cheers,

|-|ardy

Offline Hardy

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Re: FMC company route file format for simulators
« Reply #8 on: December 23, 2012, 02:13:09 PM »
[Edited]

Sorry, my previous example with degrees and minutes was too simple. We need an example that inlcudes seconds. So, here's my second edit:


Example of a latitude:

ARINC: 30303075

30 degrees, 30 minutes, 30.75 seconds

Convert this to degrees and fraction of a degree.


Method A:

Characters 1 thru 2 show degrees
30 / 1 = 30
Characters 3 thru 4 show minutes
30' / 60' = 0.5
Characters 5 thru 8 show seconds * 100
3075" / 600000" = 0.005125  << critical part (wrong), should be /360000
Result: 30.505125

Reverse conversion:
30.505125 - 0.505125 = 30
Replace the 0.505125 fraction by a minutes value
60' * 0.505125 = 30.3075'
30.3075' - 0.3075' = 30'
Replace the 0.3075 fraction by a seconds value
60" * 0.3075 = 18.45"
ARINC : 30301845


Method B:

Characters 1 thru 2 show degrees
30 * 3600" = 108000"
Characters 3 thru 4 show minutes
30' * 60" = 1800"
Characters 5 thru 8 show seconds * 100
3075" / 100 = 30.75"
Result: 109830.75" / 3600" = 30.5085417

Reverse conversion:
30.5085417 - 0.5085417 = 30
Replace the 0.5085417 fraction by a minutes value
60' * 0.5085417 = 30.512502'
30.512502' - 0.512502' = 30'
Replace the 0.512502 fraction by a seconds value
60" * 0.512502 = 30.75"
ARINC : 30303075


I'm using method B. Does this agree with your results?


Cheers,

|-|ardy




« Last Edit: December 23, 2012, 09:33:48 PM by Hardy »

Offline Hardy

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Re: FMC company route file format for simulators
« Reply #9 on: April 03, 2013, 08:05:03 AM »
Good morning forum,

oops, what happened? Some posts in this thread have been deleted. Where are the replies of that gentleman (Fabo ...?) with whom I discussed the above math problem?

Anyway, I just came back to this thread because I wanted to ask if Christian has noticed this problem or whether someone from the beta team has forwarded the above notes to him.

Christian, if you read this, and if you have a spare minute, could you mail me the formula you're using to convert ...

- a PFPX file lat/lon string
- to a single value with just one decimal point? (degrees or radians, whatever)

Either there's an error in the database or in the conversion. If we compare the conversions, we could isolate the problem in a few minutes.

Good luck with your project!


Cheers,

|-|ardy

mail: info at aerowinx.com






Offline JAP

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Re: FMC company route file format for simulators
« Reply #10 on: April 03, 2013, 08:18:53 PM »
Hello Hardy!

Unfortunately it was mentioned on another thread that Christian doesn't visit the forums with the same frequency as before. The beta team members on the other hand post quite often. I hope they will be able to help you!

I'm not quite sure if this will help, but I had a quick look at one of my old programs I made for boating. It did similar conversion for plotting raw GPS data. I used the method B and have managed to stay afloat ;)

----

@Peter: sorry to hear that :(
« Last Edit: April 03, 2013, 08:49:40 PM by JAP »
Jarkko Puustinen

Offline Hardy

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Re: FMC company route file format for simulators
« Reply #11 on: April 04, 2013, 04:39:17 AM »
Hello JAP!

I hope they will be able to help you!

Well, I'm not really asking the PFPX team to help me. I'm trying to help the PFPX team :-) I, too, think method B is the correct one, and that's the one I have been using.

In other words, to help us all, all customers.

But then, it's just a fraction of a mile, the error can be seen only when the map is zoomed in. It's not a problem that will kill people.

Thank you for your reply, JAP.


Cheers,

|-|ardy

Offline Pierre95

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Re: FMC company route file format for simulators
« Reply #12 on: April 04, 2013, 07:59:18 AM »
Good morning forum,

oops, what happened? Some posts in this thread have been deleted. Where are the replies of that gentleman (Fabo ...?) with whom I discussed the above math problem?
.....

|-|ardy

mail: info at aerowinx.com

Hi Hardy,

as the person to whom you allude became "undesirable" after some words hurtful and incompatible with the ethical obligation on this forum, I asked the banning of it.
So I decided to erase all messages of this person.

sorry for the inconvenience

Best Regards
Pierre

Offline Hardy

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Re: FMC company route file format for simulators
« Reply #13 on: April 04, 2013, 10:13:50 AM »
Hi Pierre,

I don't understand your "ethics". Wasn't this just a mathematical discussion? We talked about numbers. The context of this thread is now destroyed.

Well, it's your forum. But, perhaps, you should recheck your "ethics"? We all make mistakes.


Best wishes,

|-|ardy

Offline JAP

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Re: FMC company route file format for simulators
« Reply #14 on: April 04, 2013, 11:03:20 AM »
Hello Hardy!

I didn't realize that my "help" comment could be misinterpreted, but you are correct :)

From the info (currently present) on this topic, I would agree that all PFPX users would benefit, if this "problem/finding" was investigated thoroughly. What I meant is that not all forum members have access to the needed data.

---

Now back to the topic. It has now been three months since the original data was posted. It might have been a Navdata problem (if PFPX uses custom Navdata format) or a "bug/feature" in PFPX that has already been corrected.

Why am I interested in this topic? Here is a scenario that I think might cause problems (if all coordinates do not match):

I always have 2 different "entities" that "handle" the created flight plan: 1) ATC program I'm going to use and 2) the aircraft I'm going to fly.

How would I do this with PFPX? I would export the flight plan in "default FSX" format (from PFPX) and then import it to the ATC program. When in the cockpit, I would enter the planned route manually to to aircraft's computer.

The problem? If the exported flight plan has different coordinates for the waypoints, than the aircraft's database, you can quickly see that I would get a lot of "you are off your assigned route" calls from ATC.

---

How can we check if the still is a problem? As Bangor VOR was used on this thread (having different coordinates?) and is a well know navaid, it could be again used for testing. I'm just thinking out loud but here is how I would go:

1) Check that the current Navdata from Navigraph and Aerosoft (for PFPX) have the VOR in "correct" position.

2) Create a flight plan in PFPX that includes the Bangor VOR

3) Export the plan to different flight plan formats

4) Check that the coordinate conversion produces "correct" results.

-----

As we do not have access to PFPX or the Navdata, we would require help from the PFPX team. I know you are extremely busy, but I hope you find this problem worth having a look at.

Thanks!

- Jarkko
« Last Edit: April 04, 2013, 10:00:54 PM by JAP »
Jarkko Puustinen