- From: <tim.ousley_at_ni.com>
- Date: Tue, 2 Sep 2003 08:54:28 -0500
LabVIEW tracks its own memory usage, so changing the handle to point to a
non-LabVIEW memory area will probably cause LabVIEW to crash the next time
that array is internally copied, freed, or resized.
Another way to do this is to pass a LV array to the driver, lock the memory
pages, and DMA directly into that.
Copying data is usually pretty fast compared to the speed of MIO boards, so
you will probably be able to keep up with your DAQ board even without a
zero-copy design.
Tim Ousley
Multifunction DAQ Software
National Instruments
Have you seen the Measurement Hardware DDK for LabVIEW?
http://sine.ni.com/apps/we/nioc.vp?cid=11737&lang=US
Ian A Smith
<ias_at_roe.ac.uk> To: comedi_at_comedi.org
Sent by: cc:
comedi-admin_at_come Subject: mapping memory to labview arrays
di.org
09/02/2003 08:12
AM
I have a pci dma input card which writes data to memory. I'd like that
data to end up in a labview array without copying it there. I can't
change the area of memory the i/o card uses.
Can I change the handle of a labview array to point to the memory area
used by the i/o card?
TIA
--
Ian A Smith Telephone: +44 (0) 131 668 8255
Royal Observatory Fax: +44 (0) 131 668 1130
Blackford Hill Web: http://www.roe.ac.uk/
Edinburgh
EH9 3HJ
UK
_______________________________________________
comedi mailing list
comedi_at_comedi.org
https://cvs.comedi.org/cgi-bin/mailman/listinfo/comedi
Received on 2003-09-02Z12:54:28