Export FMU to .net wrapper

[BruceBoc]

Hello,

I’m a new user of OpenModelica. I would like to use FMU generated by OpenModelica in a .net wpf application.
has anyone ever used Femyou? when I load an fmu created with OpenModelica, the visual studio compiler tells me that it cannot find the dll which is nevertheless in the fmu. It’s work with BouncingBall.fmu but not with a OpenModelica FMU…
I’m using visual studio 2022, with OpenModelica 1.24 64 bits with his gcc compiler on Windows 10.

Thanks

[AnHeuermann]

With the nightly build and the next release version of OpenModleica (v1.23) our FMUs are self-contained and have all needed runtime dependencies collected in the bin directory of the FMU (see #12065). This is mainly pThreads library and maybe CVODE for CoSimulation FMUs.
But so far the FMU importing tools I tested are missing a call to SetDllDirectoryA before loading the DLL. We fixed this for OMSimulator by updating fmi4c (robbr48/fmi4c@0e0d970).

You can check if tools like Dependencies are able to load your DLL from the FMU. If yes, maybe you'll need to update Femyou to call SetDllDirectoryA as well. If no open a new issue.

Another option is to remove the need for runtime dependencies in the first place. For this you have to re-compile the source-code FMU. We have some documentation about this in our user's guide. In addition you'll need to disable linking to threads by altering the following:

fmu/sources/CMakeLists.txt

# Look for a threading library and see if it is PThreads.
find_package(Threads)
# If we find a threading library and it is PThreads then we enable its usage.
if(Threads_FOUND AND CMAKE_USE_PTHREADS_INIT)
  set(OM_HAVE_PTHREADS ON)
# Otherwise threading will be disabled.
else()
  set(OM_HAVE_PTHREADS OFF)
endif()

---

And keep in mind that OpenModelica exports 2.0.4 FMUs (that version of the standard was released in 2022) and the version of Femyou I found was last updated four years ago.

[BruceBoc]

Sorry for the late response, I've tried a lot without success.
I decided to use python with FMPy instead of Femyou.

I use OpenModelica version 1.4 under Windows 10.
This works in Model Exchange version but not in co-simulation.

Here is the python console :

Model Info

  FMI Version        2.0
  FMI Type           Co-Simulation
  Model Name         Modelica.Fluid.Examples.PumpingSystem
  Description        Model of a pumping system for drinking water
  Platforms          c-code, win64
  Continuous States  5
  Event Indicators   10
  Variables          426
  Generation Tool    OpenModelica Compiler OpenModelica v1.24.0-dev-65-gaeb2e6716f (64-bit)
  Generation Date    2024-05-14T23:03:10Z

Default Experiment

  Stop Time          2000.0
  Tolerance          1e-06
  Step Size          0.4

Variables (input, output)

  Name               Causality              Start Value  Unit     Description
Traceback (most recent call last):

  File C:\Winpython\WPy64-31230\python-3.12.3.amd64\Lib\site-packages\spyder_kernels\py3compat.py:356 in compat_exec
    exec(code, globals, locals)

  File n:\python\essais\temp.py:17
    result = simulate_fmu(fmu)     # simulate the FMU

  File C:\Winpython\WPy64-31230\python-3.12.3.amd64\Lib\site-packages\fmpy\simulation.py:761 in simulate_fmu
    result = simulateCS(model_description, fmu, start_time, stop_time, relative_tolerance, start_values, apply_default_start_values, input, output, output_interval, timeout, step_finished, set_input_derivatives, use_event_mode, early_return_allowed, validate, initialize, terminate, set_stop_time)

  File C:\Winpython\WPy64-31230\python-3.12.3.amd64\Lib\site-packages\fmpy\simulation.py:1258 in simulateCS
    fmu.doStep(currentCommunicationPoint=time, communicationStepSize=output_interval)

  File C:\Winpython\WPy64-31230\python-3.12.3.amd64\Lib\site-packages\fmpy\fmi2.py:580 in doStep
    self.fmi2DoStep(self.component, currentCommunicationPoint, communicationStepSize, noSetFMUStatePriorToCurrentPoint)

  File C:\Winpython\WPy64-31230\python-3.12.3.amd64\Lib\site-packages\fmpy\fmi2.py:206 in w
    res = f(*args)

OSError: exception: access violation reading 0x0000000000000000

No DLL problems found whith Dependencies
I also test to change fmu/sources/CMakeLists.txt and compile with FMpyGui but the error message during compilation is : Failed to compile shared librairiy

# Look for a threading library and see if it is PThreads.
find_package(Threads)
# If we find a threading library and it is PThreads then we enable its usage.
if(Threads_FOUND AND CMAKE_USE_PTHREADS_INIT)
  set(OM_HAVE_PTHREADS OFF)
# Otherwise threading will be disabled.
else()
  set(OM_HAVE_PTHREADS OFF)
endif()

Model Info

  FMI Version        2.0
  FMI Type           Co-Simulation
  Model Name         Modelica.Fluid.Examples.PumpingSystem
  Description        Model of a pumping system for drinking water
  Platforms          c-code, win64
  Continuous States  5
  Event Indicators   10
  Variables          506
  Generation Tool    OpenModelica Compiler OpenModelica v1.24.0-dev-65-gaeb2e6716f (64-bit)
  Generation Date    2024-05-15T00:36:28Z

Default Experiment

  Stop Time          2000.0
  Tolerance          1e-06
  Step Size          0.4

Variables (input, output)

  Name               Causality              Start Value  Unit     Description
Compiling platform binary...
C:\Users\Alex\AppData\Local\Temp\tmp6vkm6xtk\sources
call "C:\Program Files\Microsoft Visual Studio\2022\Community\VC\Auxiliary\Build\vcvarsall.bat" x86_amd64 && cl /Oy /Ob1 /Oi /LD /I. /I"C:\Winpython\WPy64-31230\python-3.12.3.amd64\Lib\site-packages\fmpy\c-code"  /FePumpingSystem shlwapi.lib PumpingSystem.c PumpingSystem_functions.c PumpingSystem_records.c PumpingSystem_01exo.c PumpingSystem_02nls.c PumpingSystem_03lsy.c PumpingSystem_04set.c PumpingSystem_05evt.c PumpingSystem_06inz.c PumpingSystem_07dly.c PumpingSystem_08bnd.c PumpingSystem_09alg.c PumpingSystem_10asr.c PumpingSystem_11mix.c PumpingSystem_12jac.c PumpingSystem_13opt.c PumpingSystem_14lnz.c PumpingSystem_15syn.c PumpingSystem_16dae.c PumpingSystem_17inl.c PumpingSystem_18spd.c PumpingSystem_init_fmu.c PumpingSystem_FMU.c ./gc/memory_pool.c ./gc/omc_gc.c ./util/base_array.c ./util/boolean_array.c ./util/context.c ./util/division.c ./util/doubleEndedList.c ./util/generic_array.c ./util/index_spec.c ./util/integer_array.c ./util/list.c ./util/modelica_string_lit.c ./util/modelica_string.c ./util/ModelicaUtilities.c ./util/omc_error.c ./util/omc_file.c ./util/omc_init.c ./util/omc_mmap.c ./util/omc_msvc.c ./util/omc_numbers.c ./util/parallel_helper.c ./util/rational.c ./util/real_array.c ./util/ringbuffer.c ./util/simulation_options.c ./util/string_array.c ./util/utility.c ./util/varinfo.c ./math-support/pivot.c ./simulation/jacobian_util.c ./simulation/omc_simulation_util.c ./simulation/options.c ./simulation/simulation_info_json.c ./simulation/simulation_omc_assert.c ./simulation/solver/delay.c ./simulation/solver/fmi_events.c ./simulation/solver/model_help.c ./simulation/solver/omc_math.c ./simulation/solver/spatialDistribution.c ./simulation/solver/stateset.c ./simulation/solver/synchronous.c ./simulation/solver/initialization/initialization.c ./meta/meta_modelica_catch.c ./simulation/solver/nonlinearSolverHomotopy.c ./simulation/solver/nonlinearSolverHybrd.c ./simulation/solver/nonlinearValuesList.c ./simulation/solver/nonlinearSystem.c ./external_solvers/dgesv.c ./external_solvers/dgetrf.c ./external_solvers/dlamch.c ./external_solvers/ilaenv.c ./external_solvers/xerbla.c ./external_solvers/dgetf2.c ./external_solvers/dgetrs.c ./external_solvers/dlaswp.c ./external_solvers/ieeeck.c ./external_solvers/iparmq.c ./external_solvers/dgemm.c ./external_solvers/dger.c ./external_solvers/dscal.c ./external_solvers/dswap.c ./external_solvers/dtrsm.c ./external_solvers/idamax.c ./external_solvers/lsame.c ./external_solvers/i_nint.c ./external_solvers/pow_di.c ./external_solvers/s_cmp.c ./external_solvers/s_copy.c ./external_solvers/enorm_.c ./external_solvers/hybrj_.c ./external_solvers/dpmpar_.c ./external_solvers/qrfac_.c ./external_solvers/qform_.c ./external_solvers/dogleg_.c ./external_solvers/r1updt_.c ./external_solvers/r1mpyq_.c simulation/solver/cvode_solver.c simulation/solver/sundials_error.c
Traceback (most recent call last):

  File C:\Winpython\WPy64-31230\python-3.12.3.amd64\Lib\site-packages\spyder_kernels\py3compat.py:356 in compat_exec
    exec(code, globals, locals)

  File n:\python\essais\temp.py:17
    compile_platform_binary(fmu)

  File C:\Winpython\WPy64-31230\python-3.12.3.amd64\Lib\site-packages\fmpy\util.py:920 in compile_platform_binary
    binary = compile_dll(model_description=model_description,

  File C:\Winpython\WPy64-31230\python-3.12.3.amd64\Lib\site-packages\fmpy\util.py:894 in compile_dll
    raise Exception('Failed to compile shared library')

Exception: Failed to compile shared library

I also added this without success at the very beginning of the program to the already decompressed FMU:

dllDirectory="E:/FMU/Modelica.Fluid.Examples.PumpingSystem/binaries/win64"
os.add_dll_directory(dllDirectory)

Only the "model exchange" mode works, but apparently you cannot modify the values during simulation in this mode, and the performance would be worse?.
Modelica.Fluid.Examples.PumpingSystem.zip

[casella]

@BruceBoc OMC 1.4 is Jurassic, and FMI export there was really very primitive. We've made a lot of progress since then 😄.

Please use a recent version of OpenModelica: 1.22.3, or possibly the 1.23.0 beta when it will be released, or the nighty build.

[BruceBoc]

Sorry, i wanted to write 1.24. I use the last beta.

[casella]

@BruceBoc maybe you need to set the cvode solver for the CS mode. The default solver is explicit Euler, if your system is stiff, all kind of things can go wrong.

[BruceBoc]

Altready test. Always the same problem. I have also test Dynamic or static link...

[BruceBoc]

When i tried to recompile the FMU in FMPy :

Compilation en cours...
omc_math.c
spatialDistribution.c
stateset.c
synchronous.c
initialization.c
meta_modelica_catch.c
cvode_solver.c
C:\Users\Alex\AppData\Local\Temp\tmpqjgcemrm\sources\simulation\solver\cvode_solver.h(35): fatal error C1083: Impossible d'ouvrir le fichier include : 'omc_config.h' : No such file or directory
sundials_error.c
C:\Users\Alex\AppData\Local\Temp\tmpqjgcemrm\sources\simulation\solver\sundials_error.h(45): fatal error C1083: Impossible d'ouvrir le fichier include : 'omc_config.h' : No such file or directory

[AnHeuermann]

We don't have a buildDescription.xml file yet, see #10548

For now you need to re-build the CVODE CS FMUs with CMake:
https://openmodelica.org/doc/OpenModelicaUsersGuide/latest/fmitlm.html#compilation-process

[bflo96]

@BruceBoc Hi! Did you ever managed to load the FMU using Femyou?
I have a similar issue, but I was trying to avoid migrating to FMPy .

[BruceBoc]

I have never managed to load an Fmu in co simulation mode, whatever the method. I've given up for now.