Waveform Chart and acquisition.

[Loris!!]

Ciao,

sto effettuando un'acquisizione dati analogica continua da due canali. Ottengo un' array di waveform con le due forme d'onda. Ora vorrei sfruttare per la visualizzazione un waveform chart in modo che l'utente possa vedere apparire  i dati mano a mano che vengono acquisti ( questa esigenza nasce dal fatto che le acquisizioni sono molto lunghe). Vorrei che alla fine dell'acquisizione sul chart rimanesse tutta la forma d'onda acquisita . Quest'ultima operazione mi sta creando dei seri problemi, per il settaggio delle X.

Grazie

Hello,

I'm doing continuous analogue data acquisition from two channels. I get an array of waveforms with the two waveforms. Now I would like to use a waveform chart for visualization so that the user can see the data appearing as they are purchased (this requirement stems from the fact that the acquisitions are very long). I would like the whole waveform to remain on the chart at the end of the acquisition. This last operation is creating serious problems for me, for the X setting.

Thanks

[RavensFan]

You're a new member, so you should read the announcements at the left hand side of the Discussion Forums board, particularly Posting Basics.

Note that if you want to post in Italian, there is a forum for foreign languages under Regional Communities.

The LabVIEW board is the English board, so I'm glad you translated your message.

The main problem with your message is that you posted a short description of your problem.  But you failed to include the VI that is giving you the trouble.

The hardest VI's to debug are the ones we can't see!

[Loris!!]

Thanks for your reply. I have the following  hardware for the acquisition: NI USB-6259. My question is: in the case of a continuos acquisition can i show on the waveform chart all the history of data acquired ? I tried to set the property node X range maximun  and minimum but the display is not too beautiful because with the passage of time the data are "compressed" and become of not immediate identification. You need to zoom in through the chart's palette to see the waveforms. Is it possible to maintain all the data history by displaying it on several "screens" of the plot that the user can move with the scroll bar of the plot ?I hope I was clearer.

I am attaching a sample code of the acquisition I am using.

[RavensFan]

Right click on the chart, Visible Items.  X Scrollbar

Of course you need to make sure your chart history is larger enough to hang onto the data for as long as you plan to run this.  But not too large that you run out of memory.

[Loris!!]

I tried setting x range minimun equal to zero and x range maximum to the maximum  of the acquired samples and I added the scroolbar. But I don't get the desired effect, let me explain better: the data does not flow, it enters from the right side and accumulates on the left side. In the long run it becomes impossible to see the data unless the user magnifies the graph manually. Is there any way to avoid this?

[RavensFan]

I don't think you actually read my message.  I never said to mess with minimum or maximum.  I said turn on the X scrollbar.  That will give you the ability to scroll through data that is wider than the range of your X axis.