It all depends on what you want the signal to look like. LabVIEW 7.x has an Express VI called Simulate Signal for sine, square, triangle waves. On the Analyze>Waveform Generation palette, there are lot of possiblities including one that will generate a waveform from a formula. None of these functions are available in the base version of LabVIEW but you could alwasy use the numeric functions or formula node to create an array. If you can define the signal mathematically, LabVIEW can create it.
