Voltage Reads Zero on NI-9234

Updated Jan 18, 2019

Reported In


  • NI-9234
  • USB-9234

Issue Details

I am reading a signal on my 9234, but I just see a flat line on the test panel in NI MAX. Do I need to be doing something different?


This is most likely caused by one of two issues: either the plot is not set to auto-scale, or the task is configured improperly.

Be sure that the "Auto-scale plot" checkbox is checked on your Test Panel.

If you are using an IEPE sensor, be sure that theĀ "IEPE Excitation" checkbox is checked and coupling is set to "AC."

Additional Information

Sound and Vibration inputs are typically in the mV range. This means that, if the "Auto-scale plot" checkbox is not checked, it will default to the full range of your device, and the signal will not be visible.

IEPE devices, such as microphone, require excitation, which is specified by the "IEPE Excitation" checkbox. IEPE sensors also typically require AC coupling, which removed the DC component of the signal.


Not Helpful