UDP Protocol - Change in OBJL Command

Question

Hello everyone,

I am currently working with X-Plane as a visualization tool connected to my flight simulator, which is running in Matlab/Simulink. For different flight scenarios I would like to add various objects to the scene for which we are using OBJN and OBJL at the moment. OBJN works perfectly and it is possible to add objects to the scene but we are unable to move any of the generated objects with OBJL. 

The data format given by the instructions suggests:

xint index + xdob lat_lon_ele[3] + xflt psi_the_phi[3] + xint on_ground + xflt smoke_size

4 Bytes + 24 Bytes + 12 Bytes + 4 Bytes + 4 Bytes = 48 Bytes

If I sum up all these data sizes, the message should be 48 Bytes in total. If I send this message to X-Plane 11, the application tells me that it is expecting 56 Bytes instead. What am i missing?

Answer 1

Hi Muglug,

I am not with Laminar Research; just a flight simmer from down under.

I suggest you deal directly with Laminar Research by starting with [email protected]   

I am of the opinion that your issue is more of an integrated development issue rather than a flight simulation issue while attempting to fly an aircraft.

Good luck

Glenn

Comments

Hi Glenn,

thanks a lot for the reply.

I already contacted Laminar Research directly, but thought that maybe other people ran into the same problems. In the meanwhile I already found an alternative solution to the problem: By simply adding a 8-byte buffer of zeroes to the end of the command, X-Plane stopped complaining and everyone seemed fine. After further inspection, the whole command seemed to be shifted though. In the end i ended up changing the listed protocol to the following:

xint index + xint Buffer + xdob lat_lon_ele[3] + xflt psi_the_phi[3] + xint on_ground + xflt smoke_size + xint Buffer

4 Bytes + 4 Bytes + 24 Bytes + 12 Bytes + 4 Bytes + 4 Bytes + 4 Bytes = 56 Bytes

While does not represent the official command protocol, it still works out for my communication between Matlab/Simulink and X-Plane 11.

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Glad to know all is working.

Glenn