[Daniel_H]

Thank you very much, you've been very helpful.

Yes, I used the express timing block because it was the only one that (apparently) would deliver a timer with less than 1ms, since the input is not an integer number, now I see it doesn't.
I guess there's no way around it.. I didn't use the timed loop structure because it's limited to 1kHz, what I didn't know is that I am also limited by 1kHz either way.

About the last paragraph, thanks for the tips, I'm going to make it more efficient. Is there a way to limit the size of an array from the start? let's say, 1000 positions. I guess if I use "Delete from array" block, the samples are still going to be there, but not being used, so there's going to be memory allocation anyway.