Write to text file while scrolling table issue

[Martin.D]

Hi all,

I have a LabVIEW application that logs data using 'write to text file' every second. This is a bckground task in a sub-VI. On the main screen I have several tables that have scrollbars. Every time the file is written the scrolling of a table is effectivley canceled. It is then necessary to click on the scrollbar again to re-start scrolling the table. I guess this is an issue with the OS but not sure yet. I have not tested other operating systems yet. I thought I would try the forum first. Has anyone else experienced this issue? Any ideas on how to fix this?

I have tried using list boxes instead of tables but the same issue exists.

I'm using windows 7 and LabVIEW 2011.

Thank you.

[ErnieH]

It sounds like you are try to  scroll to the last entry. If this is the case, get the size of the rows and use the property node IndexVals for the table. Update this after every data change and it will scroll it down to the end of the table.

[Martin.D]

Hi ErnieH - Thank you, but I'm just trying to perform a standard scroll of the table so that I can see data that is out of view. If I click the arrows at the end of the scrollbar it works fine (or at least the issue is not noticed), but when using the sliding part of the scrollbar (located between the arrows) the issue exists. I tried it on XP with LabVIEW 2009 and the issue does not exist. The issue only exists with LabVIEW 2011 and windows 7 as far as I'm aware.

[SteveChandler]

Can you post an example that demonstrates this? I will see if I can duplicate it. I am using 32 bit LabVIEW 2011 on Windows 7.

[Martin.D]

Hi Steve, thanks for offering to help. Right now I'm on a machine with LabVIEW 2010 and XP and the issue does not exist. But I have created a little test VI that should demonstrate the issue once running on LabVIEW 2011 SP1 and Windows 7. I can't confirm this VI will demonstrate the issue until later today when I can test it on the problem system myself. Feel free to give it a go and let us know what you find, or wait until I confirm the attached VI will demonsrate the issue (10 to 12 hrs time).

Thank again.

[SteveChandler]

The scrollbar works fine for me. LabVIEW 2011 32 bit on Windows 7 Home Premium 64 bit. I do not have SP1 on this machine.

[Martin.D]

OK - Thanks for trying it. I will try the same bit of code on the appropriate target system later and see what happens.

[Martin.D]

Hi Steve, I solved the issue. Much to my surprise the VI I posted previously worked without issue on my windows 7 PC. Finally I tracked the problem down to the loctaion of the text file being written to. It was located in a directory that was under LabVIEW project control and the directory was 'Auto-populating'. Oops!

Anyway I hope this post may help someone else someday.

Thank you.

[SteveChandler]

Hah, that is hillarious! I think it is a bug. You might want to post a summary in the June 2012 Bugs Thread on  Breakpoint with a link to this thread.

[Martin.D]

Not sure its a bug myself. Posted on the bug thread anyway. Certainly worth knowing about though.