I don't know abour STDF format, according to wikipedia it is some sort of binary file holding test data, and in this respect you could use standard read/write function for binary files to interact with this format. However this does not seem to be so simple as the specifications cover several data types and
Googling a bit I have found a free C library under development, but in this forum thread a user has failed to use it in CVI (don't know which release it was testing in 2012, though). You may want to take a look at the LabVIEW library for STDF and see if you can manage in packing it into a DLL to call in CVI.
