what are the buffer or the DMA, when I want to acquire an image; what is the whole process?

[beocien]

Hi,

I'd like to use LabView to save images with my frame grabber. I have an IMAQ.

I looked at some examples and they always use the imaq init.vi, the imaq configure trigger2.vi, the imaq configure list.vi, the imaq configure buffer.vi, and imaq create.

I looked at the help for each of them but I was wondering what is a DMA, or a buffer.
and what happen when I want to use 5 buffers instead of one?

It looks like the images is transfered to a ram before being acquire or something like that.

Can someone tell me what the process is when an image is being acquired?
That may help me to understand what DMA, buffer mean.

thank you

[ThSa]

Hi,
here is one KB for the configure list buffer and configure buffer functions of the IMAQ driver:
http://zone.ni.com/devzone%5Cconceptd.nsf/webmain/487D3523EAA8255686256BB90076BF70?opendocument

The hard limit of the buffer number has been removed since the IMAQ 3.0, but the "old" board 1408 uses the old driver achitecture. To increase the buffer number for this, open MAX, go to Tools - IMAQ - 1408 Support -> Max Number of Buffers (you need administrator rights to change the value).
The new value take effect after a restart of the system.

To get more information about DMA, read the following KB:
http://zone.ni.com/devzone/nidzgloss.nsf/10ce50b61f969f5a86256879000d3a01/b6b8ccde8f0a626b8625686a00793f38?OpenDocument

regards,
ThSa