During MIL testing, the Simulink model is simulated, whereas during SIL testing, the code generated for the Simulink model under test is run as an executable to simulate the system.
First, inspect the Simulink Test Manager UI to verify that the model actually ran and you did not experience an error during code generation, a run-time error, or a model build issue that caused the Test Case to show as a failure.
If the test did run, a likely issue is there is a mismatch between the output of the generated code ran as a SIL simulation and from the MIL Simulink simulation. You can use the visualization tools within SDI or the Simulink Test Manager to view these differences.
There are many possible reasons for the mismatch between model simulation results and SIL simulation results, and the issue is not likely due to anything in Simulink Test. Some examples of the reasons are described in the following documentations:
1. If you use elements like MATLAB Function Blocks in your model: https://www.mathworks.com/help/releases/R2024a/coder/ug/expected-differences-in-behavior-after-compiling-your-matlab-code.html
2. Numerical issues: https://www.mathworks.com/help/releases/R2024a/rtw/ug/numerical-consistency-of-model-and-generated-code-simulation-results.html
To debug such issues, it is recommended to directly compare the results generated by the model simulation and SIL simulation and examine the differences to determine what specific behavior may be different. The warnings generated during simulation can also provide helpful indicators in identifying the root cause of the issue, since the generated code may be exhibiting unexpected behavior as indicated by the warnings.
To debug the generated code itself during a SIL simulation, the following workflow can be used:
