multiple signals in one chart

[KJos]

Hello all,

I've got a problem with a vi I created, in this vi I need to plot two signals in one chart.

These signals will eventually come from external inputs.

The chart only displays one signal and this signal isn't even displayed properly.

I can display each of the signals in a separate chart, but I want them together in one chart.

I really can't figure out what I'm doing wrong and I would really appreciate some help.

Kind regards,

Jos

[NIquist]

I'm not sure exactly what you're trying to do but see my changes for how to show two plots.

[KJos]

Sorry, I'm currently using Labview 7.1 and can't open your file.

Can you post it again so I  can open it or is there a way around this?

Btw I'm trying to compare a calculated stress (by entering the dimensions and force exerted on a part) with a measured stress (by meausuring the strain with strain gauges).

You have to enter the force exerted on a part, the dimension and youngs modulus of a part, after which the vi calulates the stress.

The incoming signals will be the strain from the strain gauges and the force from a load cell.

Ps The text is all dutch

[NIquist · Accepted solution]

It's very simple.  Just use bundle to combine the points and wire to your chart (see pic).

[KJos]

Thank you very much for your help, my problem is solved.

But could you tell me what I did wrong.

Were the signals going in to the chart the wrong type? Or was it the merge feature?

Because I used merge another time, at which time the chart displayed both signals (I think)

Message Edited by KJos on 02-26-2010 09:38 AM

[NIquist]

To be honest, I've never used an "Express" function so I'm not familiar with them.  I've been using LabVIEW since version 4 and I'd rather use the low-level functions because they tend to have much less overhead than the wizard-like Express VIs.  It IS a good way to learn though.  Right-click on an Express VI after you have configured it and select 'open front panel'.  It will then become a VI that you can look into and see how the low-level functions are wired together.

In your VI I only used the bundle function to send both point to your chart.  I think I also set the Y axis to autoscale (VERY important!).  And changed the plot1 color to white.

Check out the examples for more info:  Help > Find Examples...  then look in 'Building User Interfaces' > 'Displaying Data' > 'Graphs and Charts'.  The 'Charts.vi' is a good place to start.