Top 8 channels on NI-DAQCard-AI-16XE-50

Hi, I'm pretty new to Comedi but I'm picking it up fairly quickly, however
one problem has me a bit stumped...

I have made a few simple modifications to the cmd.c example provided with
comedilib-0.7.19. Originally it reads data from 4 channels, and I modified
it to read data from the 16 channels (subdevice 0). The first 8 channels
(0 to 7) work perfectly, however the last 8 (8 to 15) decend rapidly to
zero ('0') and remain there for the duration of the acquisition. The
channels have ac signals applied, or are grounded, so I would have
expected to see them oscillate or remain constant somewhere around
32768...

What am I missing here? Is there anything special about the top 8 channels
within Comedi or on the board itself that I need to consider? I'm using
AREF_GROUND also if that's relevant.

Thanks in advance, appreciate your time,

David

David Antliff                       dave_at_med-dev.co.nz
Design Engineer
Med-Dev Ltd.                        tel. +64-4-972-7661
Wellington, New Zealand             www.med-dev.co.nz

Received on 2002-08-27Z01:48:12