Sampling Rate and Acquisition Modes of the PXIe-4480/4481

Updated Nov 18, 2019

Reported In

Hardware

  • PXIe-4480
  • PXIe-4481

Issue Details

  • At what rate can I sample with the PXIe-4480/4481?
  • When can the PXIe-4480/4481 run at 1.25 MS/s/ch and when can it run at 20MS/s/ch?
  • What is the difference between Frequency Domain Mode acquisition and Time Domain Mode acquisition?

Solution

The PXIe-4480 and PXIe-4481 have two acquisition modes that can be used, each with a different maximum sample rate per channel.
  • When using the device at 1.25 MS/s/ch or below the device will automatically be running in the Frequency Domain Mode.
  • When the device is running above 1.25 MS/s/ch to a maximum of 20 MS/s/ch the device will automatically switch to Time Domain Mode.

Frequency Domain Mode Acquisition
The PXIe-4480/4481 uses analog and digital filters to condition the signal for more accurate representation of the signals within the desired band of analysis. The three important bands to consider are the passband, the stopband, and the
alias-free bandwidth.

Time Domain Mode Acquisition
The PXIe-4480/4481 which extends the sample rate and bandwidth beyond that of traditional DSA devices by using this mode for rates above 1.25 MS/s/ch. This mode is useful to measure signals which have a rapid changes that need to be analyzed. To allow for higher bandwidth measurements, the Time Domain Mode significantly alters the signal processing done in the Frequency Domain Mode.