Simulink Playback Block Dropping Ports

When I save a model and close it, the next time I open it my playback block outputs say ground and I have to go manually reconnect them to the data in the workspace.

This seems to be a new issue in 2024b as we've used Playback blocks for years without issue.

The blocks work fine as long as the model is open, but when I close it, there is a good chance the Playback block loses it's outputs. It doesn't happen every time, but it's > 1 out of 3.

Answer 1

[Isha]

Hello,

The description (Playback block ports reopening as Ground after saving/closing in R2024b) looks to me like a possible unintended behavior change for the block’s port assignments.

You can also leverage the openExample('simulink/LoadMessageDataIntoModelUsingPlaybackBlockExample') and see whether the issue still exists.

For further information you may contact MathWorks Tech Support https://www.mathworks.com/support/contact_us.html.

Hope this helps.

[Brad]

We load timetables from workspace. The timetables have multiple variables that serve as the ports to the playback block. Are there any special limitations or best practices we should follow to avoid the problem in that kind of configuration?

[Brad]

The default example does not exhibit this issue, though it's loading data from a file, whereas we are loading timetables from the workspace. The variable in the workspace may or may not be present at the time the model is opened, but is always present before the model is run.