Very few of us are Mind Readers. If you don't tell us, we cannot accurately "guess" the type of Motor you are using, what DC voltage it wants, and how it "reports" its speed.
Your question seems to be along the lines of "My LabVIEW Program doesn't work." What LabVIEW Program? I can "guess" that it has a Control (of some sort) for Motor Speed, perhaps an Indicator for "Actual Motor Speed", and something called "Voltage" (unclear whether this is an Input, something you set, or an Output, something you measure (looking at it from the Motor's Point of View).
Provide us with more information. We don't usually do your homework for you, so be sure to attach all of the relevant LabVIEW code you have written (or are trying to use). Be sure to attach complete VIs, as LabVIEW .vi files, though you can also attach a picture of part of a Block Diagram (although those are rarely as helpful for us).
You should also tell us a little bit about your LabVIEW installation -- what Version (LabVIEW 2020? LabVIEW 2017?), is it 32-bit or 64-bit, and what Hardware are you using to drive and measure your Motor.
