PDA Graph cursors problem

[andrej]

Hi,
I have LV PDA Module 8.5 and Windows Mobile 5 OS on PDA.
When using Zoom Graph or Chart.vi on XY Graph cursor position are changed?!?

Best regards,
andrej

[NoahR]

Hi andrej,

Thanks for contacting National Instruments.  I was wondering if I could get a little more clarification from you about your question.  When you are creating your PDA VI, what actual functions or controls are you using that you have questions about?  When you say "Zoom Graph" and "Chart.vi" what exactly are you referring to? The Waveform Chart? Or other functions?  Also, I was wondering what exactly you mean by the cursor position changing.  What are you seeing on your graph? Would it be possible for you to walk me through some of the steps that you are taking in order to reproduce your issue? Please let me know some of this information and I will be able to work on it a little more efficiently on my own time.  Thanks a lot and I hope to hear from you soon!

Noah R.

[andrej]

Hi!
I will describe it in details.
"Zoom Graph or Chart.vi" is on Application Control panel.
I have XY Graph and two vertical cursors. I set cursor0 X position to 100 and cursor1 X position to 150. Then select X-zoom option in ZoomStyle control, press zoom button and select region on graph. When done cursor0 X position is 120 and cursor1 X position is 140. X positions vary according to region you select. If you are attentive you will notice that after zoom cursors stay on the same position on screen and not move with X scale as they should.
This is huge problem for application I make and I didn't find workaround yet.

VI and exe are attached in cursor.zip.
It's made in LV PDA Module 8.5 and build for Windows Mobile 5.

Thanks for your help Noah!

andrej

[NoahR]

Hi andrej,

I am having a little trouble reproducing your question using your sample VI.  When I select the zoom type and press zoom, I am not able to zoom in on anything at all.  What steps are you taking in order to actually zoom in on the graph? Also, when you say you select a region on the graph, how exactly are you doing that? A little more information might help out with getting an answer for you and I will continue to see what I can come up with to see if this is actually expected behavior or not. Thanks and I hope to hear from you soon!

Noah R.

[andrej]

Hi Noah!
First you select zoom type, press zoom button and then you select region on graph (drag cursor on graph to select region). If your select zoom type rectangle you will see rectangle on graph while dragging.
I hope this helps.
Have a nice day!

andrej

[NoahR]

Hi andrej,

Thanks for the information.  I think I may have a suggestion for you that will help you out.  When you have your XY graph and you zoom in on a particular area, you may want to programmatically change the X position of the cursor on your graph.  You can do this by right-clicking on your XY Graph from your block diagram and selecting Create>>Property Node>>Cursor>>Cursor Position>>Cursor X.  From the LabVIEW Help about this particular property, it states that the X Position for this property is the coordinate that corresponds to the plot itself.  I hope this helps and good luck with using it in the future. Thanks!

Noah R.

[andrej]

Hi Noah,

I think that problem is in "Zoom Graph or Chart.vi". I have demonstrated this in attached archive.
If you look in a code you will see that I take your advice and use property nodes. I also added Dialog that should pop up after zooming is done because it is in sequence structure.
But if you run program you will see that dialog pop up before zooming is done. So, I assume that  "Zoom Graph or Chart.vi" cause problems.
Thanks!

andrej

[NoahR]

Hi andrej,

I have been looking at your code and what I see after running the code in Highlight Execution is that you basically have a race condition in the last sequence of your sequence structure with your dialog box and the cursor position properties.  If you could create some sort of data flow condition here in order to ensure that the cursor positions are moved BEFORE the dialog box appears that would help.  You might try to add another sequence after this sequence structure that takes care of this dialog box.  I hope this helps you out some. Thanks!

Noah R.