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Hi, me again . I am currently in big confusion about the way LV stores the FPGA configuration bitstream for a RIO device. As mentioned in other posts I have a setup where my project is transfered to a PXI controller where some SW framework loads it in a plugin approach. My project employs a R series FPGA board. I had some confusing experiences with this where the oscilloscope showed clearly different behavior than what the implementation should do. After some time I noticed it was seemingly and old bitstream used. I then introduced a revision number for my FPGA design that is set to a constant in the FPGA top-level VI and actually I saw that there was the wrong bitstream being loaded. The way I do it is with the "Open FPGA VI Reference" VI that is configured to use a bitstream. The bitstream is actually copied to the build destination directory and is the latest according to the timestamp. But I doubt that really this bitstream is used because a) I once deleted it on the target system and my design would still boot happily boot without throwing an error when calling the Open FPGA VI Reference VI and b) my VI that calls the Open FPGA VI Reference VI is about 1 MByte big. Somehow I have the feeling that the FPGA VI is compiled into this VI although this is not stated anywhere. So the question is what might I be doing wrong here or whether this is the way it is supposed to work. At the moment every time I did a new synthesis of the FPGA is explicitly open the "Open FPGA VI Reference" VI configuration dialog and point it to exactly the same bitfile and with this I have not seen a "wrong bitstream" problem but it is not nice to do so. Best regards flintstone