nidaqmx analog input polarity

[JGS]

I know that I get a signal from 0 to 1 Volts.

So I want to set the polarity for the analog input to unipolar.

I tried setting 0 and 1V while creating the task with DAQmxCreateAIVoltageChan

I also have searched (all) options in DAQmxSetChanAttribute, but did not find this attribute.

With creating the task and with setting channel attributes, I tried to set the low value to 0, and to set the high value to 1V. Subsequently retrieving the minimum and maximum value always did return the same negative/positive values i.e. bipolar.

Where to look for polarity setting ?

Jos

[BasvanDijke]

Hi Jos,

The polarity will automatically be set by DAQmx when you choose the right configuration of the inputrange (min: 0 and max:1).

Could you please try to run a standard DAQmx example from the example finder?

What DAQboard do you have and what version of DAQmx?

Could you try to do this in MAX?

Regards,

Bas van Dijke

AE, Netherlands

[JGS]

Hello Bas,

Your assumptions that is should work are right. I was too fast with my question.

As I - start to - develop acquisition applications at my desk, I often have to write from interface board manual and (now with NI-DAQmax) virtual devices. I have been using the wrong vritual device that indeed cannot switch between unipolar and bipolar. The control NewPhysChanAICtrl in Labwindows/CVI makes it almost too easy. I think I am going to look for routines that also show the physical board description.

Thanks, Jos