Trim required (elevator) offset?

[rjfon1]

Good morning all.

Question for Pete or others.

Unable to locate a trim required offset for the elevator. I have located aileron and rudder, but can't find the elevator. Looked under fs2004 controls with no luck. Would it have another description? Thanks in advance for any replies.

Rob.

[Pete Dowson]

Good morning all.

Question for Pete or others.

Unable to locate a trim required offset for the elevator. I have located aileron and rudder, but can't find the elevator. Looked under fs2004 controls with no luck. Would it have another description? Thanks in advance for any replies.

Rob.

 

Your question is a little confusing. Do you want the assignable control, or the writeable offset?

 

Elevator control offset is at 0BB2 (just before the Aileron and Rudder offsets), and the elevator trim control offset is at 0BB2, just a little later in the list. Similarly you can find AXIS ELEVATOR SET and AXIS ELEV TRIM SET controls in the List of FS2004 controls, also just by searching for "elev".

 

I think you need to find a new search program, because searching the PDF with either Foxit Reader or the Adobe PDF reader finds these things immediately!

 

Pete

[rjfon1]

Sorry Pete.

I should have been more specific. I know the trim offsets you mention, but was enquiring into the 'required' trims on each axis.

Theses are 0490 (aileron), and 0498 (rudder), as per fsuipc for programmers document. These are 64-bit floating point which can be read, working in conjunction with 0480 and 0488 respectively. I was thinking these values could be read and these values converted to be used by motors for a rudementary force feedback system. Unfortunately the most important (elevator) seems to be missing. Hope this clears up my grey question.

Thanks

Rob.

[Pete Dowson]

Theses are 0490 (aileron), and 0498 (rudder), as per fsuipc for programmers document. These are 64-bit floating point which can be read, working in conjunction with 0480 and 0488 respectively. I was thinking these values could be read and these values converted to be used by motors for a rudementary force feedback system. Unfortunately the most important (elevator) seems to be missing.

 

 

Hmm. Clean forgot about all those. They are obviously all part of the facility encompassing offsets 480 through to and including 4A0. I think those were added on request for someone who had some use, but I don't recally what they were for and I don''t know who uses them.

 

Evidently, whatever the original application was, it didn't include Elevator Trim. Sorry.

 

Anyway, you say they could be READ? It looks like they are meant only to be written, as values which may or may not have any effect according to bits in 4A0.

 

Either way, I'm not doing anything more with FSUIPC3. If this is needed for FSX / P3D  I could consider it for FSUIPC4.

 

Regards

Pete

[rjfon1]

Thanks Pete.

I actually only use fsx and fsuipc4, but it was my understanding that this document for programmers was the only one available with this scale of information. If there was something more recent, then I've missed it. My intent is to use it in an Aerocommander cockpit I have in conjunction with P3D and fsuipc4. I haven't upgraded yet for various reasons. If those offsets were available, including elevator, and could be read, it would be very useful for home builders, but if not, there are other ways an means. Thanks for the explanation though.

Rob.

[Pete Dowson]

Thanks Pete.

I actually only use fsx and fsuipc4, but it was my understanding that this document for programmers was the only one available with this scale of information. If there was something more recent, then I've missed it. My intent is to use it in an Aerocommander cockpit I have in conjunction with P3D and fsuipc4. I haven't upgraded yet for various reasons. If those offsets were available, including elevator, and could be read, it would be very useful for home builders, but if not, there are other ways an means. Thanks for the explanation though.

Rob.

 

The SDK contains both the FSUIPC guide for programmers and the FSUIPC4 Offsets Status List.  If you install FSUIPC3 the former is installed into you FSUIPC Documents folder too, and if you install FSUIPC4 the latter is installed instead.

 

The same applies to the list of FS Controls -- the List of FS2004 controls is installed in the FSUIPC Documents folder when you install FSUIPC3, and the List of FSX Controls is installed with FSUIPC4.

 

You've only mentioned the FS2004 Controls list (quite "Looked under fs2004 controls with no luck") and the FSUIPC for Programmers document (quote "as per fsuipc for programmers document"), so it looks 100% as if you've only installed FSUIPC3, as neither of those are installed with FSUIPC4. How has that come about?

 

Regards

Pete

[rjfon1]

Don't know.  I'll look into it, as I have registered this.

Rob.

[rjfon1]

Found the problem.  When I looked for the files, it found a backup that I had made (I generally make backups of documentation relating t my sim), and found the old version.  Just found my version in the modules folder (That should have clicked first). 

 

Looking further into it, regarding the original question, I don't think that it would be possible in the current configuration. as the READ states N/A, and the write (Which I'm not looking for remains internal.

 

I was hoping that I could get a trim value (trim required value), and convert that value into a something useful using the opencockpits DC motors card. this card can be used to output set voltages and currents to motors.

 

To explain:

 

If the aircraft is flying trimmed, then 0 volts would be sent from the card.

I wish to climb-I do that in one of two ways

1)Pull back on the stick, keep the pressure on and climb. In this case perhaps 12V and 2A(The converted and scaled value of the 'trim required') can be sent from the card to the motor as it remains out of trim

or

2)Pull back on the control, and wind in trim.  As the trim value determined reduces from X to zero, so will the voltage, reducing from 12V/2A to 0V.

Just my take on it, and am happy to be corrected if I'm incorrectly interpreting this and wasting my and anyone else's time.

Thanks.

Rob

[Pete Dowson]

I was hoping that I could get a trim value (trim required value), and convert that value into a something useful using the opencockpits DC motors card. this card can be used to output set voltages and currents to motors.

 

 

 

 

But by definition a "required" vallue is an input TO the system, not a read-out FROM it. What, in your case, is providing the input?

 

 

2)Pull back on the control, and wind in trim.  As the trim value determined reduces from X to zero, so will the voltage, reducing from 12V/2A to 0V.

 

So YOU are setting the "trim required", so why not feed an extra output from your trim wheel or rocker switches or whatever to yout servo circuit?

 

However, really only you know when you are "in trim" to the extent there's no pressure on the elevator axs of the control. With a normal home yoke or control stand which is simply spring loaded (so doesn't stay in different positions according to the trim) the central "hands off" position is when the input to the FS elevator control is zero. The trim value is then holding the aircraft's attitude in the desired "trimmed" position and will often be non-zero of course.

 

So really the value you need is the FS ELEVATOR position, not the TRIM. When that is 0 you should be stable with hands off. Reading the TRIM position is surely not the relevant thing to do?

 

Or maybe it's me not understanding?

 

Regards

Pete

[rjfon1]

I think my problem in understanding is that I have been using FFB joysticks in the past, in that I trim so there is no force on the controls to maintain the current aircraft configuration.  Unfortunately only I know that, and not the computer.  Now that you mention elevator position, I think my thoughts are flawed.  I was hoping that I could use trim required to calculate this.  What I need to do is somehow determine how to get a value for the elevator and aileron so that no input is required, ie the control will maintain it's current position without input to allow the aircraft to remain stable.

 

I need to do some more thinking.

Don't know what your thoughts might be, but you are not the person that should have to do the thinking on this one.  Not your job, and you have plenty to do.

Thanks Pete

[Pete Dowson]

What I need to do is somehow determine how to get a value for the elevator and aileron so that no input is required, ie the control will maintain it's current position without input to allow the aircraft to remain stable.

 

 

You have to think in terms of the way FS works, not a real aircraft, because FS's trim mechanism is NOT the same as a real aircraft's trim. Basically ALL three trim values available are additions, using the same units, to the control positions. So a trim offset of 100% (1.0 or +16383, depending which offsets you read) with an main control of 0 is exactly the same as a main control at 100% and the trim at 0, or both at 50% .... etc etc.

 

Now think of what happens to a normal sprung gaming joystick or yoke. Hands off it goes to centre, 0 in both axes. The pressure is only being applied by the springs when you want it off-centre, i.e. a non-zero axis value. Trimming is just the act of transferring that non-zero value from the main control to the trim, so you can relax the hold and let it go back to its 0 position.

 

Therefore, unless my reasoning is flawed somewhere (and I can't see that if so), the properly trimmed position is ONLY when the readout for the axis is 0.  So you only need to read the diversion away from 0 in order to apply your pressure or movement or whatever.

 

Regards

Pete

[rjfon1]

Thanks Pete.

Head is starting to hurt again.

More thinking required.

Thanks Pete.

Rob.