How do you update two waveform graphs at different rates?

[Fungineer]

Hi there!

This is my first post after lurking and reading for a couple of weeks.  I am relatively new to Labview so this website has been a tremendous resource.  Here's to hoping that you guys can help me out.

My problem has to do with graphing two sets of waveform data.  I have a USB-6218 DAQ device and I am acquiring a voltage reading for a thermometer and a voltage reading from a power supply.  Essentially what I want to do is update the thermometer voltage graph about once a second while leaving the power supply voltage graph updating continuously.

I know that my device can only capture data at a constant rate so I customized the DAQ capture parameters strictly for the power supply voltage.  I also know that to display the temperature data I would have to throw away some of that data so I can get just the one temperature a second.

This is where I am stuck though.  Can someone please offer some advice as to how I can go about doing something like this?  Would I have to convert the waveform data into arrays and manipulate the values?  If so, do you lose the time information in the waveform when converting to arrays?

Thanks a lot in advance!

[altenbach]

Are you talking about graphs or chars? (it seem your question applies more to charts)

All you probably need is a case statement containing your slow terminal. Then make sure it turns true occasionally (e.g. based on [i] or elapsed time).

[Fungineer]

I meant charts sorry.

I knew it must have been something simple like that.  I'm going to give it a go and see if I can achieve this.

Thanks!

[Fungineer]

So I made a case structure where if the elapsed time is 1 second then initiate the waveform.  It's a start but all it does is have a 1 second gap in the data.  I'd like for it to be continuous.  Maybe I'm not setting up the case structure correctly.  Can you please advise further?

Thank you!

PS Attached is my VI.

[Fungineer]

I apologize.  I didn't save the file before I attached it.

Attached is the correct version.

[Fungineer]

Wow sorry.  Technical difficulties.  Attached is the real correct one.

[altenbach]

Wire the "time has elapsed" boolean to the case structure.