How to use set_param(BlockX, 'SampleTime') during runtime of Simulink?

Dear Community,

i know the topic of how to use set_param() to change params of chosen Simulink Blocks is well discussed, but I couldn't get an answer to this:

As the pictures show, I got a sin(x) signal, doing 3 periods wth a certain frequency before i got another iteration with higher frequency and so on. This goes from 0.1mHz to 1kHz and I want to have 600 samples per period. Meaning that I want to change the sample time of the "Signal Editor" Block everytime I go to a higher frequency. Therefore I want the sample time to be 1/(SamplesPerPeriod*CurrentFrequency).

The counter and the matlab-fcn only get relevant when the frequency jumps to the higher value and tries to update the sample time by:

set_param('SineTest/Signal Editor','SampleTime',SampleTime_new); 

But it says that it 'cannot change parameter 'Sample Time' of Signal Editor while simulation is running' How do i solve this? Is there a way that i can change it during runtime or tell Simulink to pause, change it and resume?

Thanks for your help in advance :)

Best wishes

Answer 1

[Harald]

Hi FJ,

as the error message indicates, I don't think this can be done directly.

My recommendation would be to choose the sample time in a way that all the desired sample times are multiples of that sample time.

An alternative might be a for-loop with sim commands, capturing the final state of the model and using that as initial state (e.g., for integrators or unit delays) for the next run.

Best wishes,

Harald