on board memory question pci 6259

[Naser1363]

Hello

I have a question about FIFO memory
I have PCI 6259 and it has 4095 samples FIFO memory.
I dont understand what is fifo memory because
I use matlab to aquire signals from AI.
I set sample time 0.001 and I run matlab function then I aquire for 90 second It can save 90/0.001=90000 sample.
But it has only 4095 samples .
How i can save 90k sample when it has only 4095 samples ?

Best regards

[Jeff.St]

Hi Naser1363,

There is no need to worry.  The FIFO is for data that is actually stored on the card.  While you are acquiring samples, the card is constantly transferring those samples to your computer, which has a lot more memory.  If you acquire samples too fast, it is possible to overflow this memory.  But this shouldn't happen since you are acquiring at 1000 Hz's.

[Naser1363]

Dear Jeff.St

Thank you so much for your good help.

For a selected PCI with Maxmum sample rate NS/s and on board memory M what is maximum saplming that I can appy to this board to it cannot overflow?

assume that

1- I use 1 channel for aquire of my signal.

2- I use multi channel for aquire of my signals.

(for example for PCI 6259 N=1MS/s and M=4000 sample).

Could you please help me?

Regards

[Jeff.St]

Hey,

The PCI card can transfer samples from the card to your computer very fast.  I wouldn't worry about the transfer rate until it becomes an issue, at which point you can probably slow your sample rate down a little bit.  

The maximum transfer rate also depends a lot on your computer, so I just can't give you an answer.  You could try using a benchmarking program if you absolutely have to have an answer.  Here is a link that may help you do your own benchmarking.

http://zone.ni.com/devzone/cda/epd/p/id/38

Here is a link discussing the benchmarking of another card.

http://digital.ni.com/public.nsf/allkb/624CD9E32E2C4076862570C10000B9DE

Good luck!