I need to export a waveform to a speadsheet file. Ok, it's simple when all is ok, but in my case, the vi "export to file" is executed BEFORE the vi "create a waveform". So my file has no data, and labview returns no errors. How doing ??
It sounds like you have a dataflow problem but I'm not sure how you did that without seeing your code. If the data from create a waveform is wired directly to the export function, there's no way for export to execute first. If you're using local variables, then yes this can happen and the solution is to get rid of them or use somethng else like error in/out connections to enforce proper dataflow.
I solved the issue like this: i split the waveform to extract dt and Y then i export that using the classical "write to file" vi. I never succeeded with the direct waveform export function ?!?!?