Hi, George.
I'd combine the two VIs when you want the tasks synchronized and use the VIs separately when you want them to operate independently. (So ultimately you'd have three VI's: the combined one and the two singles.) If you were using a LabVIEW Real-Time system, it would be possible to communicate between the two with buffers and/or shared variable events, but that's a little like shooting a mosquito with a cannonball. Since your application sounds relatively simple, I'd just use regular DAQ triggering with the combined VI. Hope this answers your question!
Sarah K.
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