Christine -
In the past I have used the C/C++ Adapter to call directly into the CVI RTE functions. The CVI functions I have used are OpenFile, WriteFile and CloseFile. The functions are exported from the DLL as CVI_OpenFile, CVI_WriteFile, and CVI_CloseFile. I just had to make sure that on termination of the sequence, that the integer handle was properly released by calling the close function.
If you are using LabVIEW, you could call directly into the low level VIs to do a similar set of operations.
Scott Richardson (NI)
Scott Richardson
https://testeract.com