Mixed signal graph with buffer.

[rnishimura]

Hi I'm new to LabView and I have a really basic question.

Here's what I'm trying to do.

1. I'm using mixed signal graph to display some signals acquired from DAQmx.

2. I have 3 separate plot areas.

3. X-axises of these plot areas need to be completely sync'ed.

    which is the primary reason why I want to use mixed signal graph.

4. I want the signals to be displayed like Waveform Chart,

    that is the waveform data is not discarded upon refresh

    and I can scroll back to look at old stuff.

5. I also want to save the data as numbers to I can also

    do all kinds of calculations with them.

Right now with my vi, the graph gets refreshed and overwritten

every sampling period and only a small fraction of the data I want is

shown on screen. (I want these fractions to get appended in

chlonological order...)

I suppose this is a pretty common problem for a newbie.

I could do it easily in C or Java, but find it rather difficult to do on GUI.

Any help will be appriciated

thanks!

[T_Blaze · Accepted solution]

If you want to see time history of your graph, simply change the x-axis to not autoscale under chart properties. You can use align your waveform under programming >>  waveform >> align times. You can enable the scroll option by right clicking on graph >> visible items >> graph palette.

There are many options to save the data. The quick and dirty way is to enable indexing in your while loop and wire that to write to spreadsheet under programming >> file i/o >> write to spreadsheet file. Keep in mind the file will be a txt file.

Post your code for more help.

[rnishimura]

Hi thanks for the reply. Unfortunately, I am not allowed to post or share anything I do at work with anybody outside my organization so I will post a slightely simplified block diagram of what I have as of now. hope this is good enough. Thanks!

[rnishimura]

I have one easy question. I looked under programming >> waveform, but there seems to be no such item called "align times."

What is the exact name of the item you mentioned? (Is it "time stamp alignment?") Thanks!

[rnishimura]

I was actually sort of able to work this out on my own.

I used waveform chart instead.

I just set it to "stack plot" mode on the properties window

and was able to get the desired effect.

[abaker]

i am facing the same problem 

how did you solve it?

want to create a  mixed signal with buffered history that can be scrolled back

like a mixed signal chart

[jackwhelan]

Not sure if you found a solution but I found that the NXG version of the waveform chart supports mixed signals while preserving the chart history. Not sure it's what you were looking for but might help someone else our there who comes across this thread