FMPy | Simulate Functional Mockup Units in Python

About FMPy which is a python package for FMU simulation. I need one clarification : What is the purpose of cswrapper code, sundials solver or functions? Is it only required for ModelExchange type FMU simulation and not for Co-simulation type FMU simulation? https://github.com/CATIA-Systems/FMPy

With Python libraries like FMPy I am able to simulate fmus (using fmpy.simulate_fmu) for given start_time and stop_time. In such case, the function simulate_fmu completes the simulation and return the time-series results.

However, I want to create a closed loop between fmu and a Python function (i.e. in a Python script initialize the fmu, get the results from fmu after every 0.1s and based on that update the input value to the fmu for the next timestep). Is there a way to achieve this using existing libraries like fmpy or pyfmi?

I simulated a batch of 5 FMUs by putting a function containing the fmpy simulate in a loop. 4 of them simulate correctly. The fifth one due to a wrong parameter shows an error.

My question is, is there any way to find out in which FMU the error comes during simulation

Ideally the output should look like: FMU1: OK FMU2: OK FMI3: 'Error' and so on

I have a python script that filters and lists the parameters, their units and default values from a fmu using the read_model_description function from FMPy library and writes in an excel sheet (related discussion). Then using the simulate_fmu function the script simulates the fmu and writes the results with units back in the excel sheet.

In filtering the parameters and output variable, I use this line to get their units.
unit = variable.declaredType.unit if hasattr(variable.declaredType,'unit') else '-'

While interacting with the fmu, the parameter and variable values are in default SI units. I guess this is according to the FMI standard. However, in the modelDescription.xml under I see that there is information regarding the default SI unit to displayUnit conversion. For example:

I have a FMU of a model and the use case is to change parameter values of the FMU to see the impact on the results. Is there a way to list top level parameters of the FMU using either FMPy or pyFMI if I dont' have access to the Modelica model?

One of the process I have been following is to open the FMU using FMPy.gui and go through the list of parameters and then use them in the script but I would like to know if there an easier way of doing it so that I can list then in the Jupyter notebook and change the parameters as needed?

I am trying to test a simple fmu to save and restore the states.

For example openmodelica: