Re: Scanning different channels in continuous mode

On Wed, Feb 05, 2003 at 02:19:53PM +0100, Wim Meeussen wrote:
> Hallo,
> 
> I am trying to read 6 channels in continuous scan mode, with the 
> ni_mio_common dirver. I'm using the CVS version of comedi form one week 
> ago. My test program runs in kernel space on a x86 machine, 2.4.18 kernel.
> 
> First I initialise a continuous scan (0.5 Hz). I registered a callback 
> function (CB_EOF) so an interrupt occures after each scan. In the 
> callback function I read the comedi buffer using the 
> cfc_read_array_from_buffer(..) function.
> 
> I am having the following problems:
> 1) The first scan only contains 5 samples instead of 6. All the next 
> scans contain 6 samples
> 2) All the 6 samples I get are samples from channel 0, and none from the
> 5 other channels.

You didn't say which board you are using, which might make a
difference.

Assuming that you are using a PCI-MIO board, you should try
disabling DMA by commenting out '#define PCIDMA' around line
105 in ni_pcimio.c.



dave...

Received on 2003-02-05Z18:54:34