How can I determine the gain setting of an analog input channel on a USB-6009?

[pnsaeta]

I am using a USB-6009 from Mac OS X 10.4.2 and the DAQmx Base software. In setting up a channel I pass a voltage range, but I would like a way to query the driver software about the actual resolution achieved. Is there a straightforward way to manage this?

[Sean_C.]

Hello,

No, unfortunately there is no way to query the DAQmx Base driver for the resolution of a channel.  You will have to calculate that value based on the known resolution of your ADC and the range and gain of your configured AI Channel.  The formula for determining code width (the smallest detectable change in voltage) is Range/(Gain * 2^resolution of ADC).

Please see the following tutorial for more information:  http://zone.ni.com/devzone/conceptd.nsf/webmain/139DFA3645B29BE586256865004E742A .

I hope this helps.  Let me know if you have any further questions.

Regards,
Sean C.