Drawing limits on my waveform

[lebogzy]

I've got two waveform graphs which display a live view from my oscilliscope.

What is the easiest way to draw two parallel Y axis amplitude limits? Can i do this somehow through the property nodes? or do i have to make these waveform graphs multiplots and add dimensions to my y-array?

Thanks...

[Cory_K]

Are you asking how to set a range for your y-axis on your graph?

You can double click the graph on the front panel, and type whatever value you would like for maximum and minimum.

You can also right click the y-axis and uncheck 'autoscale Y'.

You can also set the range programmatically using property nodes.

Or did you mean you wanted to set a threshhold so data was not displayed beyond certain limits?

[lebogzy]

Cory,

Thanks for the reply. Sorry for the poor explanation. I just took a screenshot of my program and edited it in mspaint to show exactly what i need.

If you look at the screenshot, you'll see a little table on the left with 3 "threshold" numbers. These numbers are automatically calculated based on a 1st time calibration that is run at the beginning of the program. The charts below highlight the values in red if they exceed these thresholds.

All i want to do is actually DRAW these thresholds onto my waveform chart (like i did in paint with a red dotted line). Because these numbers are pretty much always different (by a few mV), i need this to occur programatically.

Message Edited by lebogzy on 06-03-2009 01:53 PM

[Cory_K · Accepted solution]

You have 2 (or more) options.

The second is FAR easier than the first, but I'll show you both anyway

1)  Build an array of a constant value, which would be your threshholds, and plot them along with your data.
      This will draw out the limits above and below the data as it is being plotted.

2) Create cursors. Use property nodes to assign their y-values according to the thresholds.

See the attached VI.

All of the code in the While loop on top is for option 1.

The ridiculously simple property node is option 2.

[Cory_K]

You could put the property nodes in a loop too.

But if they are going to be set only once, in the beginning, there is no need.

[lebogzy]

boo and ya.

Cory is the man.

[lebogzy]

i love this forum.

you guys made this, not me

[Manoj.P]

Good work.How to fix the limit in array with out while loop.i.e for constant waveform graph how to set the limits.