problems with advantage pci1711

  	

Hi all,

Is it possible to access the counter on the Advantec board pci_1711?
Thanks to Ian Abbott I now can reach the counter on pci_1710.
When using the 1711 I have a strange problem. I try to read from two channels like the following lines.
First I read a sample from one channel and load it inta a pointer and the next sample is from the other channel:

        begin {varv}
         for varv := 1 to rounds do
          begin
            channel:=0;
ret:=comedi_data_read(dev,subdevice,channel,range,aref,vm^[varv]);
            channel:=1;
ret:=comedi_data_read(dev,subdevice,channel,range,aref,im^[varv]);
            end;
           end;{varv?}

When trying to execute this data_read I get some "bleeding" over from one channel to the other. In addition, when the signal is just a few volts neg or positive in relation to aref (which is 0 volts) the signal gets noisy, more the more apart from zero the signal is.
On the other hand, when just reading from one channel, no noise exists when the signal is zeri or not.
I would like to use just comedi_data_read because using the buffer is so cumbersome and involves delays which are difficult to handle when measuring data during experiments.

I would be very grateful for some information on this.
Regards!
Per Arlock

Received on 2005-12-01Z19:56:46