DMA capability of nidaq

[eugenia]

Hi,

I have a NiDaq PCI-6115 card and I want to know which is the transfer rate of
the card.

(i.e what is the Mbytes/sec rate which the card can transfer data to the
host PC)

We have an application that acquire 500000 number of points, forms an image
and we want to display them with a rate of 5 frames per second
(500000points=1 frame). This is a real time application. How can we set up this card in order to enable the highest transfer rate?

How we can enable the DMA capability for this card?

How can we check the transfer rate of this card?

Our transfer rate needs are negligible compared to the transfer rates of the
PCI bus.

This card is installed on a Pentium 4, 2.4GHz, PC running windows XP.

Thank you in advance
 

[PBear]

Hi eugenia,

You should be completely fine running at that sampling rate. I assume that since you want 500kS five times per second, you will be sampling at 2.5MS/s. The card has 3 DMA channels and are automatically set for operation. You can, using property nodes, set the board to use IRQ but this is not recommended. The DMA transfers are handled on the driver level and sent to your ADE memory (LabVIEW) which in turn you read from with DAQmxRead calls. The DMA transfers will be fast enough but you need to ensure that you are reading from your PC buffer fast enough to avoid buffer overflow. This is more of an aspect of your program than the DAQ device.