Change from Fieldpoint to CompactDAQ AI gives strange values

[Anders Björk]

Dear all

We got a strange problem when moving from a Fieldpoint with a FP-AI-110 to CompactDaq rack with a 9203 (and also a AO, DO, DI module to in additon to the 9203, we used a 6009 before), there is one pressure sensor 4-20mA and one temperature sensor 4-20mA.

Before the change the readings were normal now they have very high noise overlaid, resulting in a pressure from -2 to 3 bar when unpressurized.

We have tried about 10 different ideas to eliminate the problem but with no success yet.

Any ideasor suggestions are highly appreciated !

Best regards

Anders

[Neville D]

Never used those modules before, but have you tried grounding any unused channels?

Also, are you getting 4ma when the pressure is 0? I've never had a pressure sensor give exactly 0 output when the input is 0 pressure. You might want to scale the values before presenting the output.

Neville.