Adding Tow Function

Hi all, I have been wanting to add a tow forward functionality to some of my older A2A planes that do not have the handy function build in. I park my airplanes in a actual hangar so pushing them in isn't a problem, but it is a bit unrealistic to start up inside the hangar. Initially I've setup just a general gauge with a single button with XML code.

I'm just a bit new-er to FSX and P3D development, I see a lot of other code using L:variables to accomplish more complex tow functions. I think these L:variables are local variables, but I am curious as to where they are declared and similar things like that.

Does anyone have any tips or thoughts when it comes to a tow XML gauge / app? For example, how would I "call" the built in function to "start push back". Basically How would I call the SHIFT+P button via an XML standpoint?

Thanks in advance!
Chris
 

tgibson

Resource contributor
Hi,

You probably need to read the SDK on XML gauges, Parameters and Event IDs to get an understanding of the system.

Basically, L: variables are defined in any XML gauge that uses them. There is no separate definition code, you just use them. They are shared by all gauges and by the MDL file's custom animations, so they can be used as "messenger" between them.

To activate an FS function, you use a K: event. For example, the command equivalent to Shift-P is (>K:TOGGLE_PUSHBACK).

I don't know about tow code, though.
 
If you want to do the action that the Shift+3 window's tow button in the A2A Comanche and Skylane does, which is using the L:VAR (L:Variable) "L:TOW", you can assign this L:VAR to a button using FSUIPC or Spad.neXt. I do not know how to do this is FSUIPC, but this is how to do it in Spad.neXt.

1. Go to the controls tab in Spad.neXt
2. Chose the control/panel that you would like your button to be assigned to
3. Select the button that you would like the tow function to be assigned to
4. Click "Add Event"
5. Click "Button Pressed"
6. Click "Add Action"
7. Click "Change Data Value"
8. Find the L:VAR "L:TOW" in the list and select it
9. Save everything

Note that you need to do this with the sim running and a flight in the sim started and be using one of the A2A planes with the tow function already implemented into the shift+3 window to do this. After you have done this it seems to work with all A2A aircraft. Other aircraft it does not seem to work.

Glad to help,
Caleb
 

rcbarend

Resource contributor
Have a look at my Groundhandling V6 package, available o.a. at SimOuthouse and AVSIM as file rcbgh-60.zip.

It includes a Taxispeed gauge, which acts as Tow function when all engines are Off.
Works for any aircraft, and any FSX/P3D version ...

Rob
 
Have a look at my Groundhandling V6 package, available o.a. at SimOuthouse and AVSIM as file rcbgh-60.zip.

It includes a Taxispeed gauge, which acts as Tow function when all engines are Off.
Works for any aircraft, and any FSX/P3D version ...

Rob
I will have a look at that. It sounds interesting. Thanks for sharing it!

Caleb
 
Thank you everyone for the replies! Eventually I will get back to this when I am more free and have a hand at creating something :)
 
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