9203 connections and DAQmx

[Greg_Reynolds]

I always get 0mA with the following: I'm using a 9203 to measure pressure from an Omaga PX-309.  The transducer has two wires, red and black.  Per Figure 3 in the NI 9203, I've connected the red lead to an AI channel on the 9203.  The black lead is connected to a power supply (+) side at 30VDC.  The negative side of the power supply is connected to the COM terminal on the 9203.

Two other channels work fine. They come directly from a 9265 analog out. 

In DAQmx the two channels (from 9265) are opened with a Create Channel, and the single channel (from PX-309) is opened with its own Create Channel.

Any ideas about my problem here??

[AnalogKid2DigitalMan]

Greg:

According to the Omega literature:

http://www.omega.com/Pressure/pdf/PX309.pdf

The red lead is (+), the black lead is (-). Good thing the unit has reverse polarity protection. Swap the red and black lead connections and give it a try.

-AK2DM

[Greg_Reynolds · Accepted solution]

That worked! Thanks much for your response.

[AnalogKid2DigitalMan]

Greg:

Glad to hear that. When I read that black was connected to (+), that was a 'red' flag 🙂 that warranted further information.

-AK2DM

[Greg_Reynolds]

Yes, connecting the black lead of the transducer to V+ seemed wrong... but it also seems unnatural to connect the black lead of the transducer to AI.  I picked the wronger way!

Thanks again