Variation in data when using 9237 with different chassis.

[Badger12]

I am trying to gather strain data and am using a NI 9944 connected to a NI 9237. During my initial setup to gather data I was using a NI 9171 to connect to my computer. With this setup I was able to gather strain data that was on the same order of magnitude and was somewhat close to what SolidWorks was telling me the strain should be. The issue is that I need to gather more data points at the same time, which requires the use of additional NI 9237, I was able to obtain a NI 9174 to house all of these DAQs, my issue is that when I take the 9237 and put it into the new chassis, with the same experimental setup and code I am off by a a factor of 10. I did go back into my LabView code and ensure that the DAQ assistant is taking data from the correct channel. 

I am wondering, what am I missing? Any and all suggestions/help is greatly appreciated!

Sidebar: Re-posting as my previous post got merged with an older post I made. I never got a response to that old question and ended up solving my problem and posted my solution to close that old post. I'm a little unfamiliar with how this forum works exactly so if this needs to be deleted and people can still see my new question as unanswered independently then awesome! 

[Kyle97330]

Are you using any "Scales" from NI-MAX?  Might be you need to apply one to the device in the new chassis.

Also just in general we strongly recommend against using the DAQ assistant for any serious projects.  It hides all of the setup data in a dialog so it's really hard to debug any issues, and the dynamic data wire it outputs is also a Bad Thing.  The sooner you learn and switch to DAQmx calls, the better.

[Badger12]

Hi Kyle97330,

Thank you for the reply! I am not using any scales that I am aware off, I only saw LabView for the first time 4-5 weeks ago. I will google and see if I can learn more about this scaling as I only have used NI-Max to check that I am getting a signal, and if I could set an offset that sounds like it would hopefully solve the problem! With respect to DAQ assistant, I was unaware of potential issues using it. I'll take a look at this DAQmx process when I have time! I assume I'd be subbing a block of code for the single DAQ assistant, so I can still take a time zero measurements and subtract from subsequent readings so I can have reasonable data?

[GerdW]

Hi Badger,

look for "DAQmx 10 functions"…

[Badger12]

Hi GerdW,

Thanks for the link!