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LabView Program acting erratically

Hi everyone,

 

We have a LabView application that we use here to test turbo blower motors. This application takes various temperature and pressure measurements, as well as vibration. All of this information is transmitted to LabView via thermocouple transmitters and pressure transducers that are connected at various parts of the piping and on the blower motor itself. All of these measurements are calculated to give us the SCFM flow and PSI pressure coming out of the discharge of the turbo blower motor.

 

Typically these measurements read steady with minimal fluctuations. Lately, however, it seems like these numbers are now acting extremely erratically, fluctuating very fast and providing a sometimes inaccurate reading, and sometimes all the fields would produce an "NaN" result. However, it doesn't do it all the time on LabView 2017 like it did with older versions. Most of the time everything is reading properly, but when it does act up, sometimes it takes a full computer reboot to clear up the issue.

 

I have tried to use an older version of our application (one that we know works), but it is still doing the same fluctuations. We also purchased new hardware and loaded LabView onto that, but still get the same results. We've checked all of our hardware connections and haven't found anything out of the ordinary.

 

Unfortunately, this LabView application was provided to us from our sister company in Korea, and their help with the issue is non-existent. Does anyone have any idea what could be happening?

 

Thank you!

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Sorry, but there's too little information to give you an answer.

 

It can be anything, from measuring your values (BTW: how do you measure these values, which sensors, which DAQ-system), from reading in these values to your LabVIEW application (again: what's the DAQ system(s)), there could be a flaw in your software architecture up to a LabVIEW error.

And of course, many other reasons are possible.

 

Regards, Jens

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I would be suspicious of two things:

  1. the DAQ device, since you said it goes away after a reboot. 
  2. a noisy environment.  Do you have any A/C lines running nearby?  Loose connections?  An unconnected cable shield can act as an antenna, introducing noise into your signal. 
aputman
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Heads up! NI has moved LabVIEW to a mandatory SaaS subscription policy, along with a big price increase. Make your voice heard.
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Just a guess but I'd lay my money on "The Software is acting exactly the way it was designed to act."

 

That does not rule out "The software delivered does not meet the design intent."  Look for race conditions and improper control loops


"Should be" isn't "Is" -Jay
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If you say "LabVIEW application", does that mean you just have a standalone executable or do you have access to the LabVIEW source code (VIs with diagrams, project, etc.).

 

If you have the source code, is there anyone at your location familiar with LabVIEW?

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