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DMA Transfers between PCI cards

I want to take data from a PCI-based NI DAQ board and retrieve it with my own PCI board for a specific application. Can an NI DAQ board write to another PCI device, or does the data transfer have to go through system memory via DMA?

Thanks

John
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Hi John,

It is possible for an NI PCI DAQ card to transfer data to another PCI card without using DMA. I have two NI PCI cards in my computer and I can directly write data from one card to the other. So, it is possible to do this but it depends on your PCI card and whether it is capable of reading data (which I assume it is). Hope this helps.

Have a great day!

Jennifer
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Jen,

Are you cards transferring data through the PCI bus, or are they using the DIO? NI came back with something different, saying basically I need to go thru host memory, and instructing my card to fetch it from memory. Maybe I misunderstood their response or I didn't ask the right question. If you would, please clarify how you are accomplishing the data transfer.

Thank


John
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Hi John,

I think I might have misunderstood your first question. My cards are communicating to each other through the PCI bus. You do need to go through the host memory in order for your NI PCI card to communicate to your second PCI card. Sorry for the misunderstanding.

Jennifer
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Hello Jennifer,

Thanks for following up, it was truly helpful.

John
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