- From: Ian A Smith <ias_at_roe.ac.uk>
- Date: Tue, 02 Sep 2003 15:18:35 +0100
Hi, thanks for the reply. I've copied into array's in the past, so I know how to do that. My application is running at around 1 mbyte/sec, so the system may cope at that rate (I haven't tried it yet) but, the application will scale up to to many channels/pci board and multiple boards. So I may need to look into changing the driver to move the target memory around... Thanks tim.ousley_at_ni.com wrote: > 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 > > > > -- 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
Received on 2003-09-02Z13:18:35