MapleSim / Modelica FORTRAN DLL Calling Convention

The Modelica modeling language supports calls from external FORTRAN libraries, however MapleSim includes support for calling functions from the C DLL, although it says it has full Modelica support and I have no choice but to use this FORTRAN DLL (I cannot reprogram its in C and I can't use other Modelica environments besides MapleSim), so I'm not in the area of ​​undocumented features.

I tried to get MapleSim to include the FORTRAN DLL and create a custom component, but it doesn't work. This is the code I got when I opened the custom component: [relevant part only]

    model ExternalCode

    function GETPSAT
        input Real TC;
        output Real PC;
    external "C" PC = GETPSAT(TC)
        annotation (
            Library = "C:/Path/To/My/DLL/FORTRAN.dll", __Maplesoft_callconv = "stdcall");
    end GETPSAT;

    equation
        (PC) = GETPSAT(TC);
        annotation (
            experiment(__Maplesoft_engine = 2));
    end ExternalCode;

      

        
        
        
      

    

I know what I should change external "C"

to external "FORTRAN"

, but what should I do with __Maplesoft_callconv = "stdcall"

? ie: what is the calling convention for FORTRAN functions? (I don't know anything about calling conventions).

Note that the parent framework MapleSim 6.1 (Maple 17) supports importing external functions from FORTRAN, so I think MapleSim will support it even though it is undocumented.

edit: By the way, the DLL was compiled with Compaq visual fortran (I don't remember the version)

edit2: The function in the FORTRAN library is exported as follows:

FUNCTION GETPSAT(TC) 
!DEC$ ATTRIBUTES ALIAS:'GETPSAT' :: GETPSAT
!DEC$ ATTRIBUTES DLLEXPORT :: GETPSAT
!DEC$ ATTRIBUTES VALUE :: TC
GETPSAT=PSAT11(TC)
RETURN
END

      

        
        
        
      

    

edit3: I don't know if this helps, but the same function can be called from C # like this:

    [DllImport("C:\\Path\\To\\My\\DLL\\FORTRAN.dll")]
    static extern float GETPSAT(float T);