Thrust Reverser Issue

[David Cox]

Pete,

I am setting up a new home-made twin throttle assembly and want to use FSUIPC to control it's input to FS2004. I have successfully set max, min and idle positions within FSUIPC but I cannot disable the reverser function when the throttles are returned to idle - current settings (both throttles) are :

Throttle1=-15409,-15409,-15409,15805

I have tried to set the idle figures to LESS than -15409 (e.g. -15600) but they always reset to the lowest figure so this obviously isn't going to work because the reversers kick-in when I return the throttles to idle.

Is there another way to disable thrust reversers in this scenario - I don't need them here as they are controlled by buttons instead ?

Many thanks

David

[Pete Dowson]

I am setting up a new home-made twin throttle assembly and want to use FSUIPC to control it's input to FS2004. I have successfully set max, min and idle positions within FSUIPC but I cannot disable the reverser function when the throttles are returned to idle - current settings (both throttles) are :

Throttle1=-15409,-15409,-15409,15805

The whole purpose of the separate throttles facility in FSUIPC was to provide an idle centre and a reverse zone. You could do what you want very easily just in FS alone.

However:

I have tried to set the idle figures to LESS than -15409 (e.g. -15600)

What would be the point of that in any case? You NEED an non-zero idle zone anyway to get an Idle position. What you are after is making the zone BELOW idle impossible to reach. If -15409 is the minimum your axis provides then you could do something like

Throttle1=-16383,-15450,-14000,15805

for example. Now the reverse range (-15450 to -16383) is impossible to reach, and you have an Idle zone from your minimum (-15409) to -14000. If that's too big, adjust the -14000, as you like.

Regards

Pete

[David Cox]

Pete,

Many thanks - I've tried that and it works perfectly - Reversers no longer cut-in when the throttles are returned to idle

David

[David Cox]

Pete,

Following on from my original post in this thread, I have now tried to use a separate joystick axis for thrust reverser throttling (in this case Thrust reverser 2) and I can't get it to work - I've re-read your documentation but can't work out where I'm going wrong. My steps are as follows :

1) Ensure the relevant axis (joystick 1, axis Z) is not assigned by FS

2) Open the FSUIPC joystick assignment tab, select joystick 1, axis Z and assign it to "Reverser 2" using the drop-down list under "type of action required" and selecting the "Send direct to FSUIPC calibration" radio button.

3) Switch to the Joystick Calibration tab and locate Reverser 2, and then set the min/max ranges by moving the axis.

As far as I can see, it should now work but it doesn't.

My FSUIPC.INI file looks like this :

[JoystickCalibration]

FlapsSetControl=0

ReverserControl=66292

MaxThrottleForReverser=-15000

AileronTrimControl=0

RudderTrimControl=0

CowlFlaps1Control=0

CowlFlaps2Control=0

CowlFlaps3Control=0

CowlFlaps4Control=0

Aileron=-16256,-1100,1100,16256

SlopeAileron=7

Elevator=-16256,-1100,1100,16256

Rudder=-16256,-200,1000,16059

SlopeRudder=15

ExclThrottleSet=No

SepRevsJetsOnly=No

Reverser1Control=66422

Reverser2Control=66425

Reverser3Control=66428

Reverser4Control=66431

FlapDetents=No

Spoilers=-16016,-7182,-1000,16015

Throttle1=-16500,-16500,-15409,15805

Throttle2=-16500,-16500,-15811,16001

Reverser2=-16384,16383

[Axes]

0=1Z,256,D,42,0,0,0

Many thanks in advance for your advice

David

[Pete Dowson]

As far as I can see, it should now work but it doesn't.

My FSUIPC.INI file looks like this :

[JoystickCalibration]

...

MaxThrottleForReverser=-15000

Why have you set this to such a strange value? The default is 0, or maybe 256.

What this now says is "don't engage the reverser until the Throttle value is less than -15000". In other words, don't engage it until it is way below max reverse already (most aircraft have a max reverse of -4096 or so).

This value is set to allow the reverser to work even if the throttle calibration isn't spot-on, and the current Throttle value (inside FS) isn't quite zero. Forward thrust throttle values run from 0 to 16383. If this parameter were set to 16384 then you could engage reverse even with throttle at full max thrust (most unrealistic). With your setting you can never engage reverse thrust!

So, why did you change it? Are you reading something I wrote somwhere that suggested it was correct? :-(

I've just re-read the description in the documentation and I cannot see how you could possibly have decided that -15000 was a good idea. (See where it says "idle zero" for instance?)

FS's throttle runs from around -4096 reverse to 0 idle to +16383 full forward. This is what calibration attempts to achieve for you, converting whatever strange values come from your joystick into the values FS understands.

Regards

Pete

[David Cox]

OK, I'll try and explain my logic here ............

My original post was all about effectively disabling reverse thrust on my throttle axis so that no matter where you position the throttle lever reverse thrust would not engage (at this stage I was using a button to activate reverse thrust on its own). To do this, I set the throttle closed position below the actual lowest reading I can obtain with the physical throttle axis :

Throttle1=-16500,-16500,-15409,15805

As you can see, the fully closed position is set to -16500 - the lever will only actually go down to about -16000 - in other words it never passes through the "Idle" zone into the reverse zone thus ensuring that the throttle always closes fully

Now, instead of using a button to activate reverse thrust I want to use a separate lever (axis) to do so which will give me reverse thrust that can be throttled just like the real thing.

So, I figured that in order to work, the main throttle would need to be closed before the separate reverse thrust throttle could be activated - in this case (allowing for small variations in the potentiometer output) I decided to set the MaxThrottleForReverser to -15000.

This obviously isn't correct as my separate reverse thrust axis does not work when my main throttle axis is closed (in fact it doesn't work at all).

I hope this explains it well enough for you to understand what I'm trying to achieve.

By the way, I have one other question related to this :

Is it possible to combine conditional arguments when assigning axes and applying them to the four "Types of action" that can be assigned (like you can with buttons) ?

e.g. If button 1,1 is pressed than perform action 1, if button 1,2 is pressed than perform action 2

Many thanks

David

[Pete Dowson]

So, I figured that in order to work, the main throttle would need to be closed before the separate reverse thrust throttle could be activated - in this case (allowing for small variations in the potentiometer output) I decided to set the MaxThrottleForReverser to -15000.

But as I explained (did you not read all of my reply?), and as should be quite clear from the documents, the FS throttle values for forward thrust operate from 0 to +16383. Idle is 0! Always!

You are completely confusing yourself with the values your joystick is providing, which is nothing to do with the FS throttle values EXCEPT insofar as they are related to them via calibration!

THE WHOLE POINT OF CALIBRATION IS TO ENABLE FS TO WORK WITH ALL SORTS OF DIFFERENT JOYSTICKS. Its values are the same always -- ZERO is always idle, a negative number is always reverse, and so on. Calibration is a process of mapping your values to FS's.

This obviously isn't correct as my separate reverse thrust axis does not work when my main throttle axis is closed (in fact it doesn't work at all).

Of course not! And I explained why! Please see above! You are asking FSUIPC to prevent the reverser when FS's throttle is above -15000. If is is below -15000 is it pretty much applying 100% thrust in reverse already!!! No FS aircraft allows this in any case -- max reverse is usually about -4096 (25%, it is set in the AIR file or by an Aircraft.CFG parameter).

PLEASE read what I am saying, and also what the documentation is saying!

I hope this explains it well enough for you to understand what I'm trying to achieve.

I know EXACTLY what you want to achieve. Just delete the line you've messed up (MaxThrottleForReverser=-15000) and it should work fine, unless you cannot always get the throttles to a complete idle (0), in which case increase that parameter a little. It really should never need touching if you calibrate correctly!

Look, I'll even reproduce the reference in the documentation:

MaxThrottleForReverser=0

This controls the interlock—the reverser will not engage until all throttles are reduced to this setting (normally 0, or idle). You can try a non-zero value here if you cannot calibrate your throttles to produce a stable idle zero.

See the bit saying "the reverser will not engage until all throttles are reduced to this setting (normally 0, or idle)", even clarified by the bit saying "You can try a non-zero value here if you cannot calibrate your throttles to produce a stable idle zero"? Are YOU having difficulties setting idle? If not, why fiddle with this? If you are, you need to INCREASE it from its default of 0, not whack it right down to an impossible to reach value!!

Is it possible to combine conditional arguments when assigning axes and applying them to the four "Types of action" that can be assigned (like you can with buttons) ?

No. Sorry.

Regards

Pete

[David Cox]

OK, I understand you now - I've reset it to 0 and it works fine.

As you suggest, I was confusing my joystick values with those that FS uses.

As a matter of interest, where in your documentation does it state that FS throttle values are different to the ones the joystick is sending - I can't find it ?

David

[Pete Dowson]

As a matter of interest, where in your documentation does it state that FS throttle values are different to the ones the joystick is sending - I can't find it ?

Well, maybe it isn't as explicit as that (but see next paragraph), and I'm not sure it is my job to explain all things about FS, only to give advice about my programs, which I do, but what do you think joystick calibration is for in the first place? How can FS react in the same sensible way to joysticks with all sorts of different characteristics? I cannot understand how you could imagine that FS operates on your actual joystick values -- you've already shown how those can be "fiddled" to give you no reverse zone on a control for which half the whole range might otherwise be reverse, remember?

The main reference data I provide for FSUIPC users is in the Table which appears in the Joysticks section of the main user guide. I realise this is only reference material, but you will see that it does state that the throttles operate the way I've just mentioned. Here is the relevant part from that table:

–4096 (full reverse*) via 0 (idle) to +16384 (full forward). All four are operated together if you map a single axis assigned to AXIS_THROTTLE_SET to these.

Since FS2002 these are replaced by those with the AXIS_ prefix. FSUIPC handles both identically, except when calibrating the 4 axes separately, where there’s now an option to only process the new AXIS_ ones. This option is useful for those aircraft panels which themselves use the older controls for “fly-by-wire” type operation.

* The actual negative value for “full reverse” is defined in the aircraft parameters (the .AIR file). Since version 2.975 FSUIPC has calibrated reverse to match the aircraft, so you will see different values here, not just the nominal ‘–4096’.

Of course, the part you presumably referred to and misunderstood also rather implied, even stated, that idle was zero, don't you think? It also said not to bother changing it unless to could reliably set idle.

The main place where the ranges of all the axis controls inside FS is made obvious and more exact is the programming guide for those writing programs for interfacing direct to FSUIPC. External programs exercising direct control need to provide the values FS is using.

Regards,

Pete