Loop that reads voltage input changes

[tjhanks]

Hello, 

I am using ULx LabVIEW and a USB-231 to read and convert voltages from a high voltage power supply (I posted about it a little before but it's not too pertinent to this). 

I have part of the LabVIEW code that reads the input voltages and coverts them into the "real voltage" provided by the power supply, but I also want a continuous loop that can read when the input has changed and provide the correct value to the user. 

Anything helps, thank you! 

[Bob_Schor]

To help us to help you, attach your VI.  (My goal is to teach you how to do your work for yourself).

Is "ULx LabVIEW" a different Product from "NI LabVIEW"?  Can you tell us anything about this Software?  Does it have a "Version number"?

Bob Schor

[tjhanks]

ULx LabVIEW is a driver used for MCC DAQ products like the USB-231 I am using. Here's the link: https://www.mccdaq.com/daq-software/universal-library-extensions-lv.aspx

This is my VI so far. Takes an analog voltage signal and in the loop it scales it 25e3 (0-250kV) and has a numeric indicator. As far as reading when the analog voltage signal has changed, I'm a bit lost. 

[Bob_Schor]

Sorry, I don't look at JPEG images of LabVIEW code.  [Would you be happy if I sent you a picture of my moderate-sized Matlab, Python, or C++ routine, rather than the native text-format file?].  Please attach your work in the form of a .VI file.

Bob Schor

[tjhanks]

Apologies, here.

[santo_13]

To just read samples continuously, your implementation seems to do that alright (not the best but gets job done).

In addition, just be sure to wire a stop button to the stop terminal of the while loop and then you should be good to go.

[tjhanks]

Forgot to add the stop button before sending, thanks for the reminder. Any advice to make it better? I'm sure I can settle for this but I'm curious what could improve it. 

[GerdW]

Hi tjhanks,

---

@tjhanks wrote:

As far as reading when the analog voltage signal has changed, I'm a bit lost.

---

You should do it the other way around: read the signal continuously to detect when the signal has changed...

To detect changes you should use a shift register: it helps to compare current with previous values!