Re: [Jsbsim-devel] Matlab-JSBSim Interface

[D W. <hdw...@gm...>]

$0.02 from the peanut gallery:

> ...driving is happening tomorrow

heh heh.  I got passed on the autobahn whilst going ~150 kph in the
rain... by a lady in a MINIVAN!!!  :-)

Theory that kept me alive in Germany:
 -- red+yellow means you're about to get passed (... when the light turns g=
reen)
 -- flashing headlights means you're about to get passed by a lady in a min=
ivan
 -- honking at someone that passes you is like flipping them the bird
with both hands...

:-)

> To avoid the endian issue, I'd still probably do the
> data transfer using character strings, unless that's a really bad idea
> for some reason I'm not yet aware of.

**Bronx cheer**

Careful use of a union and htons/ntohs (or the 'long' functions if
preferred) will also avoid any endian problems... and it'll be easier
to parse.  However, use of a union (structure) complicates the idea of
providing a generic XML definition for the socket datastream.  Perhaps
you can predefine a generic union with... I dunno... 30 values in it
and then fill that up according to a non-generic XML spec?

> I totally agree with you on this...I had considered
> sending it as a delimited character string...because
> that way...as you said...no worries about precision,
> and also, it can be done using one send operation.

If your data are packed in a union, you can send the buffer pointer in
one shot.  I'll post a simple client/server that demos the idea if
necessary.

> I was thinking more in terms of something like the
> first value in the character string sent out from
> Simulink being a time value which would correspond to
> the simulation time in Simulink...that way...JSBSim
> would run at any step size specified by Simulink, and
> will also always be in sync.

If your Simulink app is running in lock-step with the JSBSim (i.e. -
you use a blocking socket read) then you get the sync for free...
right?  Every packet lands on the Simulink side of the fence at 1/120
of a second intervals.  Is more than that required?

Good work, Philippose!  I look forward to reading the article.  ;-)

D