Abnormal Readings Using the PXIe-4339 in NI MAX

Updated Nov 6, 2019

Reported In

Hardware

  • PXIe-4339

Software

  • Measurement & Automation Explorer (MAX)

Issue Details

I am using the PXIe-4339 and am getting abnormal readings in my NI Measurement and Automation Explorer (NI MAX) strain task. When I scope the strain gage, the differential/ratiometric (mV/V) value is very different from the value output in NI MAX, but it matches the value output when I use a Test Panel. What do I need to change in my task to output the right value?

Solution

This is typically an issue that occurs when using the wrong task type. The Strain task will output values with the units of strain. If you are looking for the differential output of the input and the excitation voltage, you instead want to use the Bridge type task. This task type is meant for use with bridge based sensors, like a strain gage, to calculate the differential output.