data transfer mechanism

[Iniesta7]

How can i illustrate spectaculary the difference between data transfer mechanism in Labview 2011 with Daqmx(NI PXI 6251)? 

[Brandyn]

What are you asking? Could you elaborate?

[Iniesta7]

Thanks for the re, of course i try describe the problem.

So we read samples from NI-PXI6251 card continuously. Pic about my simple code:

http://i48.tinypic.com/25h0ls2.png

We found "Data Transfer Mechanism" property node in labview of course but we should illustrate the difference. For example DMA transfer mechanism is faster than PIO we know that but we can't prove to my instructor.  So we need the proofs for example ellapsed time or something.

[Brandyn]

If I understand you correctly then you should take a time stamp before you enqueue the data and then take a timestamp when the data is received. 

[Zody]

Hi,

The easiest way to do it, just configure multiple Analog Input taks and the transfer mode to be interrupts and you will se how your CPU usage will go high.

Ion R.

[Iniesta7]

Thank you this is a good idea.We have two NI-PXI6251 cards and we would like to see CPU usage for each card in IRQ transfer mode. How can we do this?

[Zody]

Hi, you won't be able to see the difference between the two boards, however, if you configure first to run as DMA transfer and check the CPU usage, and than run as IRQ transfer and check the CPU, you will notice the difference.

[Iniesta7]

Unfortunately it's also part of my "project" to see when either board didn't get cpu in IRQ transfer mode for a while because other board have higher IRQ level.

[Zody]

I am afraid I don't follow you.

What is the goal of the project ??

Kind regards,

Ion R.