NI 9234 Input configuration - AC coupling vs. DC coupling vs. IEPE AC coupling

[abvenk]

Hi all,

I'm using the NI 9234 module with a cRIO-9068. I have an accelerometer (IMI Sensors 602D01) connected to the NI 9234. What are the guidelines for using AC coupling vs. DC coupling vs. IEPE AC coupling in the Input Configuration property node)?

Thanks!

[Larry_Morgan]

abvenk,

You should have the 9234 set to AC coupling, with IEPE current set to 2mA. In any IEPE type measurement, enabling the IEPE excitation source should also by default also select AC coupling. If you try to use DC coupling, you should get an error. 

[abvenk]

Hi Larry,

Thanks for your reply. The sensor is of "ICP" i.e. IEPE type already. Does this mean the sensor electronics will provide the excitation current, or does it still mean that I should select IEPE AC coupling? Or should I select AC coupling?

I do get different signals when I select "IEPE AC coupling" vs just plain "AC coupling".

Thanks!

[Larry_Morgan · Accepted solution]

For IEPE type sensors, they require constant current excitation that the 9234 will provide by enabling the IEPE source on the module. 

[abvenk]

Thank you for the clarification.