set_param() equivalent inside Simulink?

I may be missing the obvious here, but here's my question:

I use a MIDI controller to select one of three outputs of my Simulink model via buttons on that MIDI controller.

I have that Simulink model synced with a GUI (no easy feat by itself), but only one-way sync right now: in the GUI I display which output is selected using the event listener functions.

So Simulink model --> GUI works okay-ish.

Now I want the user to be able to also select via the GUI which output is active.

I could use a constant block supplying an input to my output selector and change that value using set_param() from the GUI. But how would I change that constant value from inside Simulink? set_param() does not work inside embedded Matlab, and I need to compile the model for performance reasons (i.e. I can't use coder.extrinsic).

Answer 1

[Kaustubha Govind]

In general, it is discouraged to change a block's parameter from another block (see the blog post How Do I Change a Block Parameter Based on the Output of Another Block?). Why not just get rid of the Constant block and create an output to the Embedded MATLAB block that controls the output Selector directly?

[Roman]

Dear Kaustubha, thank you for taking time to answer me!

I would love to use my EML block for that - but how would I send data from my GUI into that block, or query GUI variables from inside the EML block?

[Kaustubha Govind]

You can create parameters on the EML block, and set those parameters from the GUI.

[Roman]

Thank you Kaustubha, I will try that.