Splitting DAQ Assistant channels

[NaCl_phantom]

Im using an NI USB 6212 DAQ board to take the input from two strain indicators. I have previously done this with only one and worked perfectly, however, now that I have 2 I run into a problem where when splitting the data from the DAQ assistant it does not work. By does not work I mean that the data being read is plainly wrong. When both strain indicators show a micro strain of 0 the values being displayed on the indicators are not the same when they should be. 

[GerdW]

Hi salt phantom,

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@NaCl_phantom wrote:

By does not work I mean that the data being read is plainly wrong. When both strain indicators show a micro strain of 0 the values being displayed on the indicators are not the same when they should be.

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Because most of your code is plain wrong…

• Learn to THINK DATAFLOW! Then you will place the loop around the correct portion of the code…
• Learn about NOT using DDT wires, they hide the data from you!
• Learn about the meaning of coercion dots!
• Learn about array handling in LabVIEW…
• Learn about applying scales to DAQmx channels…
• Learn about the difference of a photograph of your computer screen and a screenshot…
• Learn about the difference of "providing an image of code" and "providing code"…

[dsb@NI · Accepted solution]

To get you unstuck: 
Whenever you don't get expected results, use the debugging features in LabVIEW (such as probes) to find the first place (subVI/primitive/wire) where you have expected inputs but not expected outputs.

In the screenshot you posted, you will find that you do not get expected results when converting the blue wire (dynamic data type = DDT) into the array. Instead, try converting the DDT (blue wire) into an array of waveforms. You can double click the conversion node to configure the type of the output.

You definitely don't get the results you expect from the Index Array primitive. You should not wire the blue wire into the index inputs - in fact, just leave them unwired to get channels from your array of waveforms.   -- Good luck!

 

[NaCl_phantom]

Thank you Doug I'll try it tomorrow. For context this is for a class where our professor never taught us how to use LabVIEW so im just trying things out from what we have done before so if im honest I have no idea what im doing.

[dsb@NI]

We were all new to LabVIEW once. If you are going to use LabVIEW more in school or in industry, I recommend instructor-taught courses. After taking LabVIEW Core 1, Core2, and DAQ courses, I was more effective in LabVIEW than in any other language. There are also free, self-paced learning opportunities. If nothing else, find an example to start from and add on to it rather than feeling like you have to start every assignment/project from a blank block diagram.