Hello all!

I have modified FMU SDK http://www.qtronic.de/en/fmusdk.html and use it to run models exported as .fmu using OpenModelica. During my testing, I ran into a problem, which is more of a philosophical problem than a software problem. Let's say I have the following model:

model FMITest

    Real stock(start=0.0, fixed=true);

    parameter Real par = 4;    

    parameter Real valve = par;

equation

    der(stock) = valve;

end FMITest;

The export produces model description containing:

  <ScalarVariable

    name="par"

    valueReference="2"

    variability="parameter"

    causality="internal"

    alias="noAlias">

    <Real start="4.0" fixed="true"  />

  </ScalarVariable>

  <ScalarVariable

    name="valve"

    valueReference="3"

    variability="parameter"

    causality="internal"

    alias="noAlias">

    <Real start="4.0" fixed="true"  />

All good in there. But let's say that during simulation, I change the value of "par" to 2. In my case, I would like that the value of "valve" is also changed. Currently this does not happen and there is no alias reference between"par" and "valve", which I could follow in my software. Is there a specification that says this is the way the software should work or could it be changed? I know that leaving the "parameter" keyword out from "valve" and specifying "valve = par" in equation block would probably fix this, but I would like to leave my model as it is for other reasons.

-Teemu