comedi_config with 6704

Hi,

I have a PXI 6704 from NI and it works fine with comedi. But there is 
one strange thing when using comedi_config to asign my card to a device 
file:
When I use comedi_config, the first analog output channel changes its 
state from 0 to 10V. All other channels stay at 0V. Afterwards I can set 
output voltages without problems.
When I do a comedi_config -r and asign the device again with 
comedi_config, this behaviour does not occur again.

It's important for me to control the startup behaviour, because we want 
to attach hardware to the 6704 that is designed for -5V to +5V and could 
be damaged if connected to 10V.

I tried another 6704 card, but this one also changed its state from 0 to 
10V with the first comedi_config call. So it doesn't seem to be a 
hardware problem. I'm using an old version of comedi (comedi 0.7.67 and 
comedilib 0.7.21), but the relevant files (comedi_config.c and 
ni_670x.c) haven't changed. I had a look at the source code and couldn't 
find anything that would explain a write to to the first analog output 
channel.

Has anyone exerienced similar problems? (Couldn't find anything on the 
mailing list.)

Thanks,
Harald

Received on 2004-06-03Z15:20:08