NI DAQ USB 6009 Bipolar waveform acquisition

[Tupaj]

Hi,

Is the NI DAQ USB 6009 capable of biploar waveform acquisition?  I have a waveform generator that is delivering a 0.5V amplitude triangle wave into the NI DAQ USB 6009.  The NI DAQ is connected to LABView and acquiring signals using the LabVIEW express vi. The waveform that appears is unipolar.  Terminal configuration is set to differential. Waveform that is seen is attached. Thanks. Marie 

[Dennis_Knutson]

Of course it is. You should know that just by looking at the specs.

We have no idea what you have set the acquisition for range and we have no idea what connections you have made. The waveform shown has a 1 V amplitude and perhaps your setting of the waveform generator is incorrect or you have that wired incorrectly. Look at the output with a scope and provide some details - like your program.

[Chris-NI · Accepted solution]

Hi Tupaj,

Seeing a floating voltage like this can sometimes be the result of an improperly grounded measurement.  It would be helpful, as Dennis said, to know how you have this wired up.  Please take a look at this guide to make sure the device is properly grounded:

    Field Wiring and Noise Considerations for Analog Signals - https://www.ni.com/en/shop/data-acquisition/measurement-fundamentals/field-wiring-and-noise-consider...

Furthermore, information on your software setup is important, too. 

The Example Finder also has several VIs that already do this for you.  If you are working in pre- LabVIEW 2012, look for Cont Acq&Graph Voltage-Int Clk.vi in the Example Finder.  LabVIEW 2012 will have a similar VI named Voltage - Software-Timed Input.vi.

Regards,