Waveform Chart Multiple Plots Problem

[JordanLam]

Hi, I'm new to LabView and am trying to mimic the visual side of drive cycle testing using a waveform chart. This involves having one predefined plot and a second plot that is drawn up in real time by the user twisting a knob. The aim is for the user to follow the predefined plot as closely as possible by twsting the knob. However, I'm not sure how you would go about plotting a live line without overwriting that predefined line, or even how to link up two sources of input to the waveform chart (it only accepts one input).

The image attached below shows my current logic. So far, you can load different types predefined plots (using the "Cycle Type" combo box and pressing a "load" button). The issue here is not knowing how to plot a live line using a knob starting from 0 seconds and not knowing if the predefined line will be overwritten. The second image just shows what one of the predefined plots look like. I have also attached the project and one of the predefined plots. Thanks in advance!

[GerdW]

Hi Jordan,

I'm new to LabView

You surely noticed that "Training" section in the header of this LabVIEW board, did you?

am trying to mimic the visual side of drive cycle testing using a waveform chart.

I recommend to use a graph instead of a chart when you want to combine a static plot (preset data) with a dynamically generated one (measurement signal)!

[ikaiser]

Adding to GerdW's good suggestions:

• What is the Difference Between Waveform Graphs and Waveform Charts in LabVIEW?
• Depending on how you implement you code, you might want to look up arrays and loop's shift registers.

[JordanLam]

I think a waveform chart is what I need, already read up on the difference between a chart and graph. So I'm now able to both plot the predetermined line and draw a plot using the knob live as long as the while loop runs. Now the problem is that I'd like to draw a second line using that knob (and not to continue drawing the same line) starting from 0 seconds whilst maintaining that predetermined plot. I've attached the updated project in this comment. I've also attached a rough sketch using ms paint to visualize what I'd like if that helps. The idea is that the user must follow that blue line by twisting a knob. The user's plot is drawn as time goes on while the blue line is plotted before hand. Much appreciated for the answers though!

[aeastet]

This is a really easy concept. Here is a sample of how to do what you are looking to do.

[aeastet]

I did not see the file I tried to attach

[JordanLam]

That is very close to what I want to do, but referring back to that ms paint drawing I made, that blue line must be completely plotted before hand by the data in Class1.txt. And then the user's knob input must be drawn live starting from 0. From there, the user simply follows that blue line by adjusting the knob

[aeastet · Accepted solution]

Then something like this