Hello,
I'm a little new of a poster, but a long time lurker. I'd like to thank everyone that answers here for all of the questions that I have previously read and from which I have learned so much.
I am creating an Labview FPGA based solution in Labview 12.0 32bit on Windows 7. I have a target FPGA module which captures data from an external apparatus, does some processing locally, and then uses a DMA FIFO to send this data to the host, one sample/pixel at a time.
The host takes this pixel data, does a little bit more processing to it and adds each row to a queue. This queue is then looked at, some more processing is done to the rows and they are combined together, finally resulting in a 2D array that is displayed using the 'intensity chart' indicator.
I have managed to get this running at around 10 fps, creating essentially a movie. The synchronization is done via a trigger signal sent from my external apparatus to the FPGA to keep both each row and each frame displaying correctly.
The problem has been that as I try to add a little bit more functionality to the host (specifically - I'm trying to send across 2 channels simultaneously from the FPGA by combining them into a U32, and so I need to pull that combination apart and translate it back into fixed point in an automatically indexed for loop, at which point I pass one of the channels through same processing as before before displaying just that one channel), I have seemed to hit some sort of wall of functionality in that my synchronization no longer works. That is, my image, instead of being properly centered, it is skewed so I see only half of each frame each time I display the image. Finally, when I move my mouse around, or scroll my front panel, or even hover over the start bar (and have the Windows 7 window previews pop up) or do pretty much anything else with the Windows UI, my frames start 'skipping' and they change where they overall in the horizontal and vertical direction.
This leads me to conclude that there is some resource that I am unaware of that is limited and that overflows whenever I do anything with the UI. This resource then overflows and drops some lines of pixels. When the program recovers, it goes back to displaying full frames, but by this point things are out of synch already, so I never return to a 'correct' image, although this is just a hypothesis.
Question:
Does anyone know if there is a hidden resource that Labview is using that would cause degradation of performance tied to UI changes in Windows or in Labview proper? If so, is there anything that I can do to increase this resource? If not, then is there another approach that I should be using for these type of high throughput requirements?
Thanks everyone!
Adrian