cFP-AI-111 and Burkert Flowmeter : Problem

[KevMartel]

Hello,

I have a Burkert flowmeter (Model No 8012) which have a 4/20 mA output and I want to  use a cFP-AI-111 module to read the signal.  My wiring schematics is in attached piece.

When the flowmeter is connected alone in the CfP, there is not problem, it  works well. However, when I use the burkert along with another instrument, I can see the current read on the flowmeter input increase to 21 mA.

By analysing the interaction between both circuits, I realized that the problem is caused by the fact that there is a common connection between all the inputs on the FieldPoint AI-111.  (COM terminal). Explanation -> The RTD wiring connects -24 V and COM together so the -24 V is now linked to pin 4 on my burkert applying directly 24 V to the 100 ohms resistor inside the AI-111.

Is there a solution to my problem ??

Thank you very much

[Zachmx]

You may want to check the manual to make sure you have everything connected according to the specs.

If you still have issues, we will need more info about how everything is wired. See the diagram below for connections of a three wire powered current transducer (which I think you are describing).

[KevMartel]

Hi,

I have displaced my topic in the right section.  (Field point family)

Please see http://forums.ni.com/t5/FieldPoint-Family/cFP-AI-111-and-Burkert-Flowmeter-Problem/td-p/2205312

In one of my answers, I have put a more detailed schematics. You will be able to understand exactly what is my issue. 

Thank you