Measurement in VI shows wrong values

[AKlenk]

Hi,

I have a problem in my Labview RT application concerning measurements through a PCIe 6259. I want to measure the voltage from a INA shunt monitor. When I run the task I created in my project directly, the measurement works flawlessly, showing the correct values. The same happens when I access the AI channel through MAX. However, when I want to read the channel from my VI using  the DAQMx read function, the values i receive are way to high, it almost seems as if the measurement range is exceeded.

I had used a scaling to be able to read the voltage directly as a current value, but I have tried deactivating the scaling for debugging purposes so it should have no effect on the measurement right now.

I'm running Labview 8.6.1 on both dev and RT machine.

Any help would be appreciated.

[Christian Mergl]

This would fit better in the MultifunctionDAQ forum.

When you read a Channel/Task with a Task in MAX or the Testpanels, also the DAQmx Read will be called in the background, so I wouldn't say its a malfunction of this VI/FunctionCall. I would assume there is something different in the configuration settings, e.g. Minimum and Maximum Voltage Range,

Scaling, ...

Did you also try to run one of the AI Examples (could be found using the Example Finder under LV Help menu)?

Christian

[AKlenk]

I tried making a small test VI which created a new DAQmx channel and then read a single sample from this channel (exactly how I do it in my project).

The measurements seem fine that way, so the problem has to lie with the task I created. I attached a picture of the configuration.

[AKlenk]

So, after reinstalling my complete RT system, all measurement tasks work without any problems.

[Christian Mergl]

Hey,

Sorry for my late response, I had vacation.

Great to hear that it works now.

Christian