export FMU of Supplier Blackbox Simulink model

Hi,

I am looking to convert a black box Simulink model provided to me by a supplier to an FMU. I need to convert from a .slx file to an FMU format to enable it to be used in a third party software.

My knowledge of Matlab is very basic, but I have tried, unsuccessfully, converting using the following methods:

exportToFMU2CS - https://au.mathworks.com/help/slcompiler/ref/exporttofmu2cs.html

as well as from within Simulink - https://au.mathworks.com/help/simulink/ug/export-model-as-tool-coupling-fmu.html

I suppose the fundemental question is whether it is even possible to convert a black box simulink model? as the error I get relates to the S-Function block i do not have access to:

Error in S-function 'name' : S-function 'Subsystem_sf' does not exist

ADDITIONAL INFO: I have touched base with supplier, who has initially told me that they are unable to convert the model to FMU for me. I am unsure why.

I have successfully embedded my third party model into Simulink and can Co-Simulate. However,moving forward it would be a lot more practical to use my third party software as the master, as I do not envisage modifying the Supplier model but will be heavily modifying my own model

Thanks

Answer 1

[Yash]

As for your fundamental question, yes it is possible to export a Simulink model as a Standalone FMU. There are two ways to export a Simulink model containing S-Function block as a Standalone FMU:

1) By directly exporting the Simulink model via either

1.1) Command Line Interface - exportToFMU2CS (since R2020a, to be deprecated) or exportToFMU (since R20203b, preferred command)

1.2) GUI - Save > Standalone FMU in Simulink

Do ensure that the source code of the S-Function block is on MATLAB path so that Simulink can access it. Refer to this MATLAB Answer for more info: https://www.mathworks.com/matlabcentral/answers/826290-how-to-export-simulink-model-which-contains-s-function-block-mex-file-to-stand-alone-fmu

2) S-Function Builder block: This allows you to integrate existing C/C++ code into Simulink. The S-Function Builder block creates a S-Function wrapper for your external code, enabling you to generate a FMU from it. Refer here for more info:

• Generate FMU from C/C++ Code Using S-Function Builder
• Export Standalone FMU with External C++ Code

If your S-Function is on MATLAB path but MATLAB doesn't seem to find it, refer to this for a possible resolution: https://www.mathworks.com/matlabcentral/answers/735042-s-function-does-not-exist-but-is-clearly-in-the-matlab-path