12-11-2007 12:54 PM
12-12-2007 01:49 PM
Hello NF1,
From your problem description, two possibilities come to mind. The first
is that this problem is caused by something with your upgrade. This is
because it appears the behavior did not start until you upgraded, and the same
code works on other computers. The driver you are using is relatively
old, and upgrading could cause issues. For example, NI DSA is not
supported on the Windows Vista operating system, so if you upgraded to Vista,
odd behaviors like these could arise.
The other option that comes to mind is a hardware issue. If you hardware
is not working correctly for some reason, then that could cause they types of behavior
you are seeing. I would suggest swapping out your PCI-4551 with a
different one to see if you still see the behavior.
Since the buffer on the card is a FIFO, the way to clear it would be just to
read all available samples out of the buffer. It appears that you are
already doing this, so no additional programming should be necessary.
I hope this gives you a starting point for your troubleshooting. If you still
cannot figure out what is happening, please post back with more information
such as how/what you upgraded or what troubleshooting steps you have tried.