FSX Read Instantaneous Value

[TurboCompound]

Hi all, I've been working away at my XML journey, and I had an idea for some psuedo systems logic. In order for it to work, however, I need to be able to do something using FS9 syntax XML.

I know that you can use (>L:BlaBlaSomething, percent) to store a value. But I would like to store a single value in an LVar and have that value stay the same even after it's source changes.

For example, if I wrote (A: Eng 1 RPM) d (>L:My Eng 1 RPM), then My Eng 1 RPM will always be the same as Eng 1 RPM. How would I write it such that when I trigger a given variable, the value of Eng 1 RPM at that moment is written to My Eng 1 RPM?

Thanks

 

[Anthony31]

(L:Trigger_Variable,number) 1 ==
if{
(A:Eng 1 RPM) (>L:My Eng 1 RPM)
0 (>L:Trigger_Variable,number)
}

Whenever you set trigger_variable to 1 (by some other code) the if{ } statement will run and reset the trigger_variable.

You can use whatever condition you like instead of the trigger_variable.

 

[TurboCompound]

Unfortunately, it doesn't seem to want to set the trigger to zero. I feel like the condition that initially sets the trigger to 1 in conflicting with it.

 

[Anthony31]

Well, without knowing what the initial condition is then we are just shooting in the dark here.

You will need to supply some more information on what the code is that triggers your given variable.

Here is some psuedo code but without knowing what it is you are doing it really is just guessing:

(Condition that triggers given variable) (given variable) == 0 &
if{
Any other code
1 (>given variable)
}

(Condition that resets the given variable) (given variable) == 1 &
{
0 (>given variable)
}


then later you can do this if you need:
(given variable) == 1
{
(A:eng 1 rpm) (>L:my eng 1 rpm)
}

 

[TurboCompound]

Well the good news is that I found a more efficient way do do what I was trying to do, and now my psuedo simulation seems to be working.

 

[n4gix]

And you're going to share this "more efficient way" with everyone, right?

 

[TurboCompound]

Of course. What I wanted to do was read the instant value of P:Absolute Time, then constantly subtract that value from Absolute time to keep track of the time elapsed since the variable was triggered. Fortunately, I found another method somewhere else on the forum that uses FS's 18Hz Gauge refresh rate as a timer by constantly adding 1 to an LVar.

 

[taguilo]

Of course. What I wanted to do was read the instant value of P:Absolute Time, then constantly subtract that value from Absolute time to keep track of the time elapsed since the variable was triggered. Fortunately, I found another method somewhere else on the forum that uses FS's 18Hz Gauge refresh rate as a timer by constantly adding 1 to an LVar.

That method, despite being very simple, is indeed the least efficient for getting elapsed time values.
In the wiki you will find some entries on Timers, including macros for setting and retrieving elapsed values using P:Absolute Time.

Tom

 

[Heretic]

Of course. What I wanted to do was read the instant value of P:Absolute Time, then constantly subtract that value from Absolute time to keep track of the time elapsed since the variable was triggered. Fortunately, I found another method somewhere else on the forum that uses FS's 18Hz Gauge refresh rate as a timer by constantly adding 1 to an LVar.

Neither the simulation rate nor the paused state of the sim influence simple 18 Hz timers.
For that reason, I am a huge fan of Gerry's method for a timer.

I don't know in what context you need the timer, but here's an example for how it works. The value of "elapsed time" will increase in 1 second intervals, but other values are possible (preferably larger than 1 and divisible by 18).

(P:ABSOLUTE TIME, seconds) (L:START TIME, seconds) - 1 >
if{ (P:ABSOLUTE TIME, seconds) (>L:START TIME, seconds)
(L:Elapsed Time, number) ++ (>L:Elapsed Time, number)
}