- From: Fredrik Lingvall <fl_at_signal.uu.se>
- Date: Wed, 27 Nov 2002 13:49:48 +0100
Fredrik Lingvall wrote:
> Hi all!
>
> This is how I initialize the channel list for scanning
> using comedi_command:
>
> // Setup a channel list.
> for(n=0; n<n_chans; n++) {
> if (scan_down) // Reverse order (scan from high-to-low channel).
> chanlist[n] = CR_PACK( (int) chan_vec[n_chans-n-1],range[n],aref);
> else // Normal order (low-to-high).
> chanlist[n] = CR_PACK( (int) chan_vec[n],range[n],aref);
> }
>
> where 'chan_vec' is a vector of the channels I want to scan and 'range'
> is a vector of the corresponding ranges. I use a DAQCard-1200, and
> and the scanning only works when I use channel 0 to N where N
> ranges from 1 to 7. The channels must be consecutive, that is,
> it don't work if I only use channel 1 and 4, for example. If
> I only use channel 0 the code hangs at the read instruction:
>
> ret = read(comedi_fileno(it),buf,BUFSZ);
>
> Is this due to limitations in the DAQCard-1200 or is
> it comedi related?
>
> Fredrik
>
>
I installed the same softare as above (comedi-0.7.66 and
comedilib-0.7.19) on a machine
with a NI PCI-6023E DAQ card. There were no problems on that setup. Hence,
the problem must be with the ni_labpc driver or the DAQCard-1200. Has anyone
tried waveform aquisition (using comedi command) on some other cards that
the ni_labpc driver supports? In particular, what happends if only one
channel
is used?
Fredrik
Received on 2002-11-27Z12:49:48