What is the Acquisition Rate for the PXI-407x DMMs?

Updated Nov 12, 2019

Reported In

Hardware

  • PXI-407X

Driver

  • NI-DMM

Issue Details

When I look at the PXI-407x DMM specifications, I see two numbers that seem to indicate acquisition rate. One is the 1.8 MS/s that is stated at the top of the product page and the other is the reading rate, which changes based on the number of digits of accuracy and the measurement type. 
What do these numbers mean and which one is the actual acquisition rate?

Solution

The NI PXI-407x DMMs acquire at 1.8 MS/s. However, in DMM mode you will not have access to all of this data. Each PXI-407x DMM can operate in one of two modes, DMM and digitizer. DMM mode is used by a PXI-407x DMM to perform measurements equivalent to a bench top DMM. In DMM mode, multiple samples are averaged, filtered, and weighted and then returned as one reading. This functionality makes the DMM mode comparable to bench top instruments by allowing for high accuracy, low noise measurements. The reading rate given in the specifications represents the time needed for the onboard processing.

NI PXI-407x DMMs have the additional ability to acquire waveforms by using them in digitizer mode. In this mode, you will actually be able to achieve the 1.8 MS/s acquisition rate because the averaging, filtering, and weighting functionality is removed.  Please see the tutorial in the Related Links section for more information on how a PXI-407x DMM can be used for both traditional bench top measurements and acquiring waveforms. 

WAS THIS ARTICLE HELPFUL?

Not Helpful