AISENSE and multiple sensors

[Miles Young]

I have to connect a NI 9205 analog input module in a CompactRIO 9074 chassis to a range of pressure transducers and I have some concerns with regards to single-ended connections and the AISENSE reference.

The 9074 and all the transducers are powered from the same 24V supply. The pressure transducers are ground referenced.

My question is, should I route AISENSE out to each transducer along with the signal wire? Will the AISENSE wire act as return for signal current or will it primarily go through ground?

[A.Rohde]

Hi Miles

Thank you for the post.

The following KnowledgeBase contains a lot of detailed information about how to proper wiring an analog connection.

Field Wiring and Noise Considerations for Analog Signals

https://www.ni.com/en/shop/data-acquisition/measurement-fundamentals/field-wiring-and-noise-consider...

To sum up the content there are two possible setups for single-ended measurements: RSE (Single-Ended-Ground Referenced) and NRSE (Single-Ended-Nonreferenced). The important thing to note is that if you have grounded Signal Sources like you do it is not recommended to use the RSE configurations due to the risk of ground-loops. So in your case you should be just fine with the NRSE configuration from the article.

Best Regards

Anders Rohde

Applications Engineer

National Instruments Denmark