Advanced waveform graph suggestions

[OneOfTheDans]

I'm working on a project where I need historical charting of 100-200 signals displayed on 4-5 stacked plots. I've tried all the LabVIEW tricks I know, but haven't found a good solution yet.

(1) The history depth needs to be adjustable, so I cannot use a Waveform Chart in Stacked mode.

(2) It is important for the X-axes to align, so I cannot use 4-5 separate Waveform Graphs. Even if I manually align them before execution, the plot area will change when the Y-scale values' width changes. There may be a workaround to sync the plot areas? But I've never had good luck trying to pixel-compensate between front panel items. There's always some wacky behavior, especially if resizing the panel (which I need to support).

(3) The Mixed Signal Graph simply isn't production worthy, unfortunately. It's pretty close to what I'm looking for, but it's buggy, finicky to end-users, lacks the events needed to expand it, and only comes in Modern and Silver themes, which clash with the rest of the program (NXG/System).

Does anyone have a better/easier solution? Or some tricks to workaround any of these existing limitations? Thanks!

[mcduff]

You could look into the Advanced Plotting Toolkit.

It makes nice "pictures" of plots, but you will lose some functionality. In addition, the execution speed may be slower than you need.

[santo_13]

Why would you need to display 100-200 signals? even if you display them, only a superhuman can observe everything at the same time and not to mention if there are only subtle differences between each plot and good luck with finding so many unique, easily distinguishable colours.

IMHO, Anything more than 4-5 plots on a graph cannot be distinguished by a typical human or make any sense out of them.

[OneOfTheDans]

@mcduff

thanks, I'd forgotten that was an option. Have you used the plotting framework before? Do you think it can handle realtime updates, or it's more like a MATLAB post-processing graph?

@santo_13

Yes, I thought the same when I started this project. But now I've realized there are genuine cases to view so many signals. The 100-200 signals are distributed between the plots, by the way, so it's only like 30/graph, not 200 each 🙂. One genuine case is when you expect all 30 signals to trend together and are looking for any signal that doesn't track that trend. It will stick out sorely when they're plotted together. Another is sending 30 channels to a graph and allowing users to toggle visibility to watch individual subsets of signals to their needs.

Anyway, saying 100-200 signals probably got the conversation off on the wrong foot. Even charting merely 1 signal per graph has the same limitations I posted originally. No adjustable depth on charts, cannot align x-axes of multiple graphs because the y-scale changes the plot area, and mixed-signal graphs are not production ready.

Do you know any clever way to plot stacked charts/graphs like I described? Or clever workarounds?

[mcduff]

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@OneOfTheDans wrote:

@mcduff

thanks, I'd forgotten that was an option. Have you used the plotting framework before? Do you think it can handle realtime updates, or it's more like a MATLAB post-processing graph?

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It was too slow for my needs. Really depends on the update frequency.

[MIG · Accepted solution]

To solve the X-axis alignment problem for waveform graphs, right-click on the graph, select "Advanced" and turn off "Auto Adjust Scales".

This will prevent the plot area changing size when the Y-axis values change.

[OneOfTheDans]

Perfect, I just tested and it works well with resizing scales & windows. This is enough for me to build a custom Mixed Signal Chart that meets my needs, thank you!

If I've seen that setting before, I (wrongly) assumed it was related to the AutoScale X and AutoScale Y settings.