I haven't used that feature, so I'm not completely certain of this, but from looking at the documentation it appears that if you use the Download Bitfile function, you cannot then communicate with the FPGA - there is no way to establish a connection to it. There are times when this might be useful, if the FPGA operates independently from the other software. The documentation for Open FPGA VI Reference says "The Open FPGA VI Reference function extracts the bitstream associated with the compiled FPGA VI or bitfile and stores the bitstream when you save the host VI. The bitstream contains the programming instructions LabVIEW downloads to the FPGA target." I don't see any way to establish a connection to a bitfile that is already downloaded (and possibly running). I do hope someone from NI will clarify if this is not the case.
