FMU internal solver time step - Is there any possibility to dynamically change the FMU time step after generated?

When exporting a Simulink model as a standalone FMU, I have seen information regarding how to make some parameters visible in the FMU block to allow certain configurability.

I was wondering, if there is any way to make something similar with the time step of the internal solver, so after having your FMU you can decide the time step it is running internally with. If I understood well, there is not any limitation associated with the FMI standard and I heard some compilers support this feature.

Thanks in advance.

Answer 1

[Aiswarya]

Based on my understanding of your question, it seems that you want to modify the time step size of the FMU block. In order to do this, you need to change the 'Communication Step Size' parameter of the FMU block. This parameter allows to specify the time interval between two simulation instants for the block. This parameter is described in the following documentation of the FMU block: https://www.mathworks.com/help/simulink/ref_extras/fmu.html?searchHighlight=FMU%20time%20step&s_tid=srchtitle_support_results_1_FMU%20time%20step#mw_42952658-dc8a-4e9f-86e9-9462049cd341

You can also set this parameter in the Simulation tab of Block Parameters of the FMU block as shown in the figure below:

[Tania Cuesta Cano]

Hi Aiswarya,

Thank you for your answer but I think what I aim is not related with communication time step.

From what I understood reading the documentation, the coumication step size does only allow to modify the time step at co-simulation level. What I understood is that what you modify is the time step the FMU block interchange input/output data with the co-simulation solver and other FMUs. However, co-simulation FMUs generated under this FMI standard type have inherit a solver itself. Even if you change the communication time step the internal solver would be running at the time step you had set when generating the FMU binaries.

What I was wondering is if there is any way I can change the FMU inherit solver time step.

Any thoughts?

Thank you again!

Regards.