font size shinks after days of running application

[bgauth]

Hi All

I have an issue with controls/ indicators in my built application changing to a smaller font size after a non specific time (days/weeks) of running. The application is a control and monitoring interface so it runs for weeks and months without being shut down or restarted. The solution has been to simply restart the application and run until it happens again. This works fine but its time to see if there is a real solution to this. I have attached an example of what I am seeing below.

I have seen this behavior on multiple labview runtime versions, v8.6 - 2010sp1 and on multiple computers running windows XPSp2-3. I have never run the Vi in the development enviroment long enough to see the issue, so I am not sure if this is a problem there. 

Any Ideas are appreciated. Thanks

Brian Gauthier

[mikeporter]

You might modify the code to check once a day to see what the control thinks its font and font size are. If this doesn't change there is something going on with the display itself. If it does change then LV is doing something strange.

Mike...

[bgauth]

Good Idea, I will do that and update. Thanks

[bgauth]

So I finially got around to implementing somthing that looks at the font size and this is what I found. The original font size is 36 pt in the cluster of 7 indicators and after about two and a half weeks of running labview reports that it is changed to this:

Indicator1: From 36pt to 14867pt

Indicator2: From 36pt to 4294941827pt

Indicator3: From 36pt to 119592pt

Indicator4: From 36pt to 27561pt

Indicator5: From 36pt to 23289pt

Indicator6: From 35pt to 35pt (No Change)

Indicator7: From 36pt to 4294944416pt

Seemingly Random numbers but all seem to display as about 12pt. Really Weird! I should mention that this is not isolated to this cluster as several indicators in the VI are making this change I am just logging this one cluster. The original font is defined as Application font (default) at 36pt except the one indicator that is defined as 35pt for some reason.

I just realized as I am writing this that it seems only indicators/controls in the Vi defined as 36pt are being affected by this. I am not sure if this is always true but I think I will let it run for a while longer to see if it propagates to any other controls.

Any Ideas?

Thanks

[JaredRo]

bgauth,

Is it possible for you add a property node to your code that periodically sets the font size to 36?  This may allow you to override whatever is causing the fonts to change.

The KnowledgeBase article below addresses font issues within executables.  It doesn't mention anything about font size inexplicably changing over time, but it still may provide some insight on the issue.

Why Does the Font Size Change When Running a LabVIEW Executable in Windows?
http://digital.ni.com/public.nsf/allkb/2F11E12E565D2DD5862579490062827D?OpenDocument

This is indeed a strange issue you're having.  I'd be interested in hearing anything new you discover about your application.

[bgauth]

Hi Jared,

It is probably possible, I am thinking not pracitical in lite of the fact that this seemes not only to be afftecting the main Vi but Sub Vi's as well and it also seems to be affecting anything/everything that has its font size set to 36pt. (Controls, Labels, Button Text  etc.). I am not certin if this is isolated to 36pt. application font yet since this latest instance is the first time I noticed it might be. I will try changing all 36pt font to 35pt and see if that has any effect, since this is relativily easy.

Your suggestion would answer an important question though, Can the font change be reversed?  I will try it in parallel on a couple controls.

Thanks

Brian

[RobCole]

Rest assured that you are not the only person who has seen this. The company I used to work for deployed systems that are designed to run continuously and they, too, see fonts change to much smaller than the original. It's not been quantified since it takes a couple of months to happen and the customer does not have time for extended down time. No experimenting allowed.

It seemed to be happening only on Windows XP machines. What operating system are you using?

Rob

[bgauth]

Rob, Thanks Its nice to know this might have been seen before. We are running all XP Machines.

Brian