FlexRIO FIFO DMA not fast enough

[yuval_yohai]

Hello,

I have to make an application capable of reading and writing (nor at the same time) data at a rate of 5MHz of 2 analog channels and 3 digital lines.

I have made an application that can read using U64 DMA FIFO and then unpack the data to the above channels - this is working fine and fast enough, yet it does not the opposite way. I have tried splitting the data using two DMA channels (U32 and U8) still with no luck.

I have made the FIFO's to never arbitrate and put it all in a very small vi that only read DMA yet no luck.

I have to know if the hardware can support such speed and why does it work to one direction and doesn't on the other.

Attached are two VI's - FPGA FIFO read and  RT FIFO write.

My setup:

PXIe 1071 chassis

PXIe-8100 controller

FlexRIO 7952R

RFtranciever module NI5781R

Labview 2011

Thanks,

Yuval Yohai,

CTO & Test System Integrator

TestVIEW Ltd.

[Josh_B1]

Hi Yuval,

What specific hardware are you using? Is this on a PXI system or a desktop computer? What operating system are you using? Can you clarify what behavior you are seeing when your FIFOs are not working.

Regards,

Josh B