4-20 mA current source not reading properly on AI-110

[FMW]

Thanks for your help. I will get a loop isolator and give it a try. It will probably take a week or more to get it but I'll try to remember to post the outcome.

Thanks again.

[Wayne.C]

It would be worth a quick check with a meter to verify my theory on the chassis of the instrument being tied to the common of the FP is correct.

[FMW]

With the controller and FP AC cords unplugged, I got 54 ohms resistance between the controller chasis and the com terminal of the FP.

[Eric A.]

Hi,
Can you try to measure a known voltage source with your AI-110 to ensure it is not damaged?  It also would be a good idea to compare measurements in MAX to those in a VI.  Try measuring a battery or something to see if that works properly.  If it does then connections are most likely to blame.  Can you provide a schematic of your tachometer and FieldPoint connector block?