Recording Strain data in LabView

[ake0012]

I have an NI-9237 with a 9945 and am trying to record data from a 120 Ohm strain gage in LabView. I have the strain gage mounted on an aluminum beam and soldered to wires to connect it to channels 0 1 and 2 on the 9945. The 9945 is connected by RJ-50 to the 9237 which is plugged into a chassis and connected to the computer by USB (and is plugged into the wall outlet, of course). 

I think my issue is in LabView trying to set up the DAQ assistant. In the block diagram I have the DAQ assistant wired to a waveform plot, but when I run the program it just displays a constant value no matter any strain I put on the beam.

When I try to calibrate the DAQ assistant I get error message -201398 saying that my AI.Max value is 1.0e-3 when it needs to be less than 37.49e-6. I'm not sure what any of that means

[santo_13]

If all your goal is to log data from DAQ, I recommend using FlexLogger

[Bob_Schor]

In my opinion, one of the worst thing NI introduced more than a decade ago was what I call the "Dreaded DAQ Assistant" (abbreviated "DDA") and its Evil Twin, the Dynamic Data Wire.

Go to the Web and download "Learn 10 Functions in NI-DAQmx and Handle 80 Percent of your Data Acquisition Applications" (or something fairly close to that name).  Don't read the first section (which talks about the DDA).  Using DAQmx functions directly is almost always simpler.

Another excellent source for ideas are the Examples that ship with LabVIEW.

Bob Schor

[Bob_Schor]

Hello again, @ake0012.

I see that you joined the LabVIEW Forums two days ago, and I'm guessing you haven't look at a lot of posts to get some idea of how to help us to help you.

I'm going to guess that you are fairly new to LabVIEW.  If you think of LabVIEW as a "programming language", your post is equivalent to "My program doesn't work, why not?".  The (obvious) response, which we didn't make, is show me your program.  Another thing that is helpful to us is "Tell us something about your LabVIEW environment and experience".

• What version of LabVIEW (Base, Full, Professional, Year, and 32-or-64 bits) are you using?
• You've told us about the hardware, thank you.
• How much LabVIEW experience (days? weeks? months? years?) do you have?  Is this your first program?

The most "complete" way for us to see your program is for you to close the LabVIEW Project (I do hope you are developing your code within a LabVIEW Project!), right-click the Project folder, and choose "Send To:" a Compressed (zipped) folder.  We'll need a compatible version of LabVIEW to open it, and many of the "experts" on this Forum are not using the most recent release of LabVIEW and won't be able to open your code.  An alternative method (which has drawbacks especially if your code is "messy", with long non-straight wires going everywhere) is to take a Snip of (all of) your Block Diagram and attach it as a .png file.  This has the advantage that even if we don't have a hardware driver for, say, a 9945 (I have no idea what that is, but I can "look it up"), we should at least be able to "guess" the function from the Icon that LabVIEW assigns to it.  But the bottom line is if you are having problems with your code, we need to see the code.

Bob Schor