| This package contains a
program that can be used to test DMA transfer rates and errors for the
PXR800 frame grabber on any supported Win32 system. The PXR800 transfers
images directly to PC memory by DMA (Direct Memory Access). If the PCI
bus on your computer is overloaded, you will generate DMA errors when
transferring frames. The DMA errors will cause a loss of video data.
This program will help you find the threshold where your PCI bus begins
to be overloaded. That will give you a good idea of how many frame
grabbers you can safely use on your system.
PXR_DMA provides input
displays at the top of the screen and output displays at the bottom of
the screen.
The program will list
as many frame grabbers as it finds, up to 4 in the input boxes at the
top of the screen. You can set the test parameters for each frame grabber
by changing the width and height. You can also enable or disable a
frame grabber if you would like to test fewer than the total found
in your machine. You will notice that the program has a provision for
6 frame grabbers. Currently the DLL for the PXR800 will only
recognize 4 frame grabbers. We built the program to use up to 6
because we may modify the DLL in the future depending on need.
The test results are
displayed in the output boxes at the bottom of the screen. The main
field to watch in the boxes at the bottom is the DMA ERRORS. Our boards
always transfer at real time, but not always without errors. The errors
depend on the conflicts on the PCI bus. For successful transfers you
should get ZERO errors.
This package includes
complete source code. Please feel free to modify this program and
make it your own. The project files are for Microsoft Visual C/C++ 6.0.
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