dma channel problems

[NJin]

Hello,

I really need help on this one. Using PCI-6035E I am trying to output an analog signal (actually 2 waverforms interleaved together) on 2 channels while simultaneously using the two GPCTRs to measure two separate signals' pulse widths. The VI runs perfectly on some occasions, while on others I get "no DMA channel available for use". Whenever this message appears and I try to exit labview, the nipalk.sys driver messes up and I get a blue screen crash that says "process_has_locked_pages" (I traced the locked pages to this driver). I've tested this many times and it appears to me to be totally random. I've used the Set DAQ device information VI to set the two counters to use interrupts, but I need to use the one DMA channel for
the analog output. My best guess is that there is some kind of resource conflict with something else in the PC, but I can't figure out how to change DMA assignments(I'm using Windows XP). The NI-DAQ Measurement and Automation Explorer tells me that the card is using DMA 0, IRQ 17. I've tried uninstalling all the NI-DAQ drivers, reinstalling and updating. Any help anybody could give me would be greatly appreciated.

Thanks,
Nick

[Filipe A.]

Hello;

The PCI bus has 3 DMA channels that are share in between all devices that do DMA data transfers.There is nothing you can do to change that, since that is a PCI bus feature.
The best way to go about that is to remove other devices that use DMA, such as network cards, for instance. That might free up more DMA access time for your DAQ device to execute its data trasnfers.

Hope this helps.
Filipe A.
Applications Engineer
National Instruments