MATLAB: Frame/sample rate matching in Simulink

Question

My Simulink model has a Matlab function that outputs one 1×13 vector and another 1×1300 vector. I want to interpolate the 1×13 vector by a factor of 100, and then add the two vectors together. The interpolation filters (I'm using the "Fir Interpolation" block from the DSP toolbox) don't change the size, though. I assume that they change the sample rate instead.

So I tried to serialize the data with an "Unbuffer" block. The Unbuffer block did not change the signal dimensions. I thought that maybe the vector needed to be 13×1 instead for the Unbuffer block to work, so I put in a Transpose block before it. That caused the following error:

    Error in 'GenNbfm_Sim/Unbuffer': All sample times must be discrete. No continuous or constant sample times are allowed.

I tried double-clicking on the Transpose block to inspect/modify its sample rate, but as far as I can tell it doesn't allow you to do anything with its sample rate.

Thanks for taking the time to read this, and I appreciate any help that you can offer.

Answer 1

It looks like your input to the Unbuffer block has either constant or continuous sample time. You need to force it to be discrete. Turn on Sample Time Colors to see what sample time each of your blocks/signals has.