NI9219

[swiftmoun]

Hey there,

I have been using a NI9219 for some high resolution voltage measurements in labview.

I happen to need to look at data sensor from a sensor with 4-20 mA output. Since the 9219 is current input capabilities I was hoping to use it, however for some reason when the sensor is wired up to the 9219, the differential voltages I am reading on the other 2 channels are reading absurd values.

I am following the wiring instructions provided here:

https://www.ni.com/docs/en-US/bundle/ni-9219-getting-started/page/overview.html

in labview I have a task reading the first 3 inputs (first one is the current input and the second and third are voltage input)

am I missing something? do I need to run different tasks? or is the unit not able to combine current and voltage inputs?

thank you

[santo_13]

You can mix voltage and current channels in the same DAQmx task.

Here is the article - https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z000000PAmzSAG&l=en-US

[swiftmoun]

thank you - so 2 tasks are needed.

But the fact I am using just one, does that explain why, the values reported by the read function are wrong?

[swiftmoun]

same issue with the layout proposed by the link you sent:

the voltages readings out of range as soon the current input is connected.

same behavior as I had with the project level task setup, in which I had the internal resistor selected.

I realized that I don't have the internal resistor set up right now, so I will try that next.

[swiftmoun]

same result with the internal resistor selected. I will try external resistor next I suppose. It does feel like a hardware problem to me.