Referencing Front panel thermistor reading to the block diagram

[ttandon]

I have inherited an already made VI that I am using in my lab. The front panel displays 11 thermistor readings. The 11 thermistors are physically connected to two different USB Temp and TC series box with 8 channels. The link to to hardware I have is as follows:

http://www.mccdaq.com/usb-data-acquisition/USB-TEMP-Series.aspx

One of the channels on the physical hardware (Dev1/Ti4) isn't working properly so I connected the wires to a spare diferent channel(Dev0/Ti0). I configured the Instacal and modified the Ulx in the block diagram to read that channel on the hardware as well. But I am still not able to read the thermistor reading on the front panel. I believe that the front panel pane reading the T3 thermistor isn't getting referred to the right place in the Block diagram. How do I reference the front panel to the block diagram to get it working?

This might be an easy question for a labview user but I am not really familiar with the software and I was wondering if somebody could point me in the right direction. I have attached two pictures as well for reference.

Thanks

[Dennis_Knutson]

Not only did you post a picture, you posted one taken by your phone! That's just silly. The picture doesn't even show how the reading is taken and displayed. Take a proper snippet or attach your VI.

There are numerous free tutorials that you can take advantage of.

[RavensFan]

Instead of an actual screenshot, you took actual pictures of your screen?

Instead of attaching the VI, the picture shows a tiny portion of your block diagram?

What kind of help do you expect us to be able to give?

"I believe that the front panel pane reading the T3 thermistor isn't getting referred to the right place in the Block diagram. How do I reference the front panel to the block diagram to get it working?"

I don't know what you are trying to ask with these questions.  Have you taken any LabVIEW tutorials?

[ttandon]

I wasn't sure how trivial this question might be. I have managed to acquire some more snippets. I don't know if that will help.

Thanks

[Dennis_Knutson]

No, you have attached any snippets. A snippet is a special type of image that an actually be copied into a block diagram and executed. Read the help on them.

A snippet might not be enough. The image shows some bad code design such as the stacked sequence structure and local variables. The entire VI should be rewritten. For now, use the test panel to verify that you are acquiring a signal. Prove the output of the read to see if the signal is there.

[WNM]

You can right-click front-panel indicators (or controls) and in the context window that appears, look for the "FIND" option and from there locate the terminal, local variables, references or property nodes on the block diagram associated with the indicator. any or all of those four block-diagram objects can be used to update the value of an indicator and in some cases they can even be located in a subVI if a reference to the indicator is passed to the subVI.

BTW, the "snippet" that the others are railing about is a special LabVIEW-specific screen/code capture found under the EDIT menu. Look for "Create Snippet from VI selection". It allows you to post a picture and functional code together.

[RavensFan]

Actually, they are snippets.  They are screenshots.  Snippets are a special term in LabVIEW where you get a picture of your code, but also get the actual code with it.  When you drop the picture in a block diagram, it becomes real code.  Highlight code, go to the Edit menu, and pick Create VI Snippet from Selection.  (Though the of the Snippet creator built-in to LabVIEW is no where near as good as the Code Capture Tool addon.)

The problem with screenshots is we can't see all the code, and we can't try to run it ourselves.  For example, you used the Stacked Sequence Structure and it has 7 frames.  (Stacked Sequence Structures are frowned up, and are usually the sign of a program with architecture problems.)  We can't see what is happening in any of those other frames.

I see a few other code problems in your screenshot.  Why do you send a false value to the local variable of a boolean control?  If you used a Latch action Boolean button, it would reset automatically when it is read.

You have For Loops where you read the size of the array.  You also use Index Array with the i value of the loop to index out a value.  No need.  Just make the tunnels for your array going into that loop auto-indexing.  It will operate on each one in turn.  (Below is a snippet created by the Code Capture Tool.  It consists of a picture of your code, and actual code on a block diagram that I created.)

Back to your original question, it is impossible for us to be able to figure out what kind of problem you are having.  I see that your "T3" value is outputting an NaN.  From your code, that means it must be reading a value that is less than zero.  Right now you don't have a LabVIEW problem, you have a hardware problem.  Try creating a simple VI that just reads the analog inputs and troubleshoot what is happening with the hardware.