This content is not available in your preferred language.

The content is shown in another available language. Your browser may include features that can help translate the text.

Taking Differential Measurements with the BNC-2090A

Updated Apr 24, 2023

Reported In

Hardware

  • BNC-2090A

Issue Details

I am using a BNC-2090A to route signals to a DAQ device that only has differential input channels. How do I set up the BNC-2090A to ensure that my signals are properly read on the DAQ device?

I am measuring signals using a differential probe that terminates in a BNC cable. As far as I know this probe is measuring a signal voltage value, not a pair of values. Do I need to configure the BNC-2090A to be in 'SE' (single ended) mode in this case or in 'DIFF' (differential) mode?

Solution

In order to properly measure your signal set your BNC-2090A to be in the 'DIFF' configuration. BNC cables inherently transmit a differential pair of signals, so even though your probe terminates in a single BNC cable, that cable is transmitting two differential signals.

As shown in Figure 2-2 below, taken from the BNC-2090A's User Manual, by connecting a single BNC cable to AI 0 in the 'DIFF' configuration, the BNC-2090A will break out that BNC cable's differential pair into 2 signals and send one signal to AI 0 on the DAQ device and the other to AI 8 of the DAQ device. You are only connecting 1 BNC cable to the BNC-2090A but it will send 2 distinct signals to the DAQ device, complying with the differential input requirement.
 

Related Links

Other Support Options

Ask the NI Community

Collaborate with other users in our discussion forums



Request Support from an Engineer

A valid service agreement or active software subscription may be required, and support options vary by country.