It sounds like you are using DAQmx to automate logging to the TDMS file. Is that correct? If so, you will need to stop acquisition before opening the file in any way, including changing its position on disc (such as moving it to your flash drive).
There is no way to access or transfer any kind of file while LabVIEW (or any other application for that matter) has is open. This is the same issue as trying to open or move an Excel spreadsheet while it is already open in Excel, which would also cause an error. Since LabVIEW is writing to the TDMS file, another application, or even another instance of LabVIEW code cannot access the file.
You have a couple of options:
1) You could view the TDMS data in LabVIEW while the acquisition is occurring using a front panel control.
2) You could perform the TDMS datalogging separately from the data acquisition. Perhaps in a producer consumer design pattern (http://www.ni.com/white-paper/3023/en/). This would allow you to continue acquisition but pause logging while you view the file. While the file is open, you could continue logging to a temporary file. When you are done viewing the file, you would then append the contents of the temporary file to the end of the original TDMS file.
Cody A.
