There are two ways to do this:
1.Pass the data value or pointer of the data that generated by LabVIEW vi to your c code using "call library function"
2. Have your C code to call LabVIEW using LabVIEW activeX server and get the data from the vi.
You can find examples in NI website, search for key words like "call external routine in LabViEW" or "call LabVIEW in C"
Irene
irene_he@hytekautomation.com
www.hytekautomation.com