Difference in Excitation Voltage for the Different Modes of the PXIe-4339

Updated Oct 21, 2019

Reported In

Hardware

  • PXIe-4339

Issue Details

I have a PXIe-4339 module and we use both the ratiometric mode and the voltage mode. For the ratiometric mode, I know the excitation voltage gets corrected for the difference between expected and actual voltage. Is the buffered voltage output also corrected?

Solution

The PXIe-4339 has 2 modes: ratiometric and voltage. The ratiometric mode is used to provide excitation and measure from bridge-based sensors whereas the voltage mode is used to measure regular voltages. In ratiometric mode, the programmable excitation is able to be corrected through the use of remote sense lines. In voltage mode, instead of using the programmable excitation, a steady 2.5V signal is sent into the reference of the ADC to calculate the output. This is further exemplified in the following image.