simulink logsout empty dataset

Hello everybody,

has anybody else encountered an issue with Simulink in the R2018a release, where the logsout dataset is sometimes empty, even when the model hasn't been changed and rerunning the same simulation input object produces a complete dataset? This issue is very frustrating, and not well reproducible, as it happens sometime, but not everytime. Here's what I'm trying to do:

I have a Simulink Model, from which I generate a vector of input objects

in(1:10)=Simulink.SimulationInput(mdl);

I then modify these with different initial conditions by setting some block parameters, and then run them as a batch job (no parallelization):

out=sim(in);

Because I have selected various signals to be logged, I get a logsout dataset for each simulation run. In the postprocessing, I step through each output object out(i) and plot some results from the logsout datasets. Sometimes, some of the datasets are empty, meaning

out(i).logsout.numElements

returns zero. When I manually rerun the simulation with the respective initial condition, everything works fine. Any ideas?

Thanks for your help!

[Panagiotis Kakosimos]

Hello,

It also happens to me. I am using the same version. Sometimes logsout is empty. Is there any solution?

Regards,

Panos

[Peter Savage]

Hi, I come from the future, this bug still exists in version 2024a.

I am running many iterations of a simulink model through PARSIM. Sometimes inexplicably the

out(1, jj).yout{1}.Values.Data(1,1,end)

dataset is empty. When rerunning with the same initial conditions it runs fine and is not empty. This is proving very annoying because I am using it in a test harness scenario and I don't know if the system under test has failed or the MATLAB function has failed.

I am going to attempt to automatically rerun the tests that fail and hopefully they will end successfully.

[Peter Savage]

Note: in relation to my PARSIM situation, PARSIM appears to use data dictionaries from the saved file rather than unsaved changes that would be used by the direct run from simulink.

Answer 1

[Jayanti]

There are chances that when you compile a model, it resets the base workspace, which can sometimes affect the logging of signals, resulting in empty “logsout” value.

To address this, you can use the "Single Simulation Output" flag. By enabling this option, you can ensure that the associated simulation output variable is not reset during the compilation process.

To enable “Single Simulation Output” flag in your Simulink model

Go to Configuration Parameters -> Data Import/Export section ->Enable "Single Simulation Output" option.

This will consolidate all the simulation outputs into a single object.