why GUI and Loop freeze ?

[dannyz]

Hi,

I'm using Labview 8.5, XP no supspendmode.

Goal: permanent measuerements like 1 week or more.

Problem: GUI freezes and loop too after undifined time ( 40 min, 3 hours). After moving the mouse over the labviewwindow, the GUI and the loop are continuing where they stopped.

There is no error messages and data gets lost.
Perfomance and RAM ist constant.

Questions:

1) What possible reasons are there?
2) could it be the waveform chart?
3) I'M using no global varibales , but some local varibales and some array caclulations, but the loop is fine, so why should it stop after a undefined time? Labview intern Memory problem, even if the tastmanager shows constant RAM?
4) Another thing. On different PCs the program runs perfect on others not. !?
5) Why the loop and the GUI continious after mouseover??


It would help me, because during the freezing, data gets lost :-(. I want to use ist for 1 month dataaquisition and i'm just taking samples over RS-232 each second with Windowstimestamps)

greetings

danny

[mfitzsimons]

Sounds like you are using (allocating) memory and running out.  The technical name for this is a memory leak.  Open Window's task manager, click on performance, and watch your memory.  If it keeps going up then you are constantly using memory like building an infinite array.

[dannyz]

Thank you for answering!

Yes the memory grows, but thats because of the waveform chart!
But again, why should freeze the GUI and the LOOP? Shouldnt there be a warning message of labview like " out of memory" ? 
maybe i should just limit the waveform chart for 1 hour, thats only 3600 points * 8 Channels.
I would like to Display at leaset 24 hours 😞 without freezing! The warning message sounds better!

greetings, and thank you for answering


danny

[arvin_labrat]

You can not really see all the points on a chart.  You can only see the number of pixles of the chart.  The best way to show more data without using more memory is to decimate the data you display on a chart.

good luck

[mfitzsimons]

Can you post your code?  3,600 points should NOT crash LabVIEW.

[Wiebe@CARYA]

"mfitzsimons" <x@no.email> wrote in message
news:1205345405804-670469@exchange.ni.com...
> Can you post your code?&nbsp; 3,600 points should NOT crash LabVIEW.

I agree. Also, a memory leak makes LV slow, but moving the mouse over a
window won't fix it! Seems to me you found a bug. Like mfitzsimons said,
post the code, or better post a stripped down version that shows the
problem.

Regards,

Wiebe.

[dannyz]

Hi,

thank you for your answers. I would like to post the code, but i have to ask first permission because parts of it is not my code.

I think i found the bug. Labview is communicating over dde.dll (FlowbusDDE) for flowmeasurements. On some operating systems , like not XP, there could happen a communication failure, so that windows could freeze the hole labview application until the mouse gets over the windows. sounds strange, but this could be the only raison, because there is no error seen by Labview.
I hope that my measurements are working finde for some weeks on windows xp pro.
dde techonology is real old, so it seems not to bee a real labview problem.

greetings daniel

i'll post the results!

[JTOM]

Hello All,

I have having the same problem for over 1 month where my application freezes after may be 1 hr or 2 hr and as soon as mouse is moved, it starts working from the point.  I am also using DDE to communicate with a VB appication.  Can this be a potential problem? 
Dannyz, is your application working fine now? Was DDE the problem?

Thanks.

[dannyz]

Hi Tom,

so I am not alone with that problem :-).  After 1 hour (50 min) i have the same problem!
The bug is the DDE communication, because i tested it without DDE. So the only way is to try on other PCs or operationsystems. I am not the expert in ddl communication but somebody told me that dde is an old communication tool wich has some bugs like that.

Are you using it also for flowcontrolling? (Bronkorst Flowdde-server?)
Is your problem only in VB or in Labview too?
Are you communicating over RS232 interface too??

What you could try is to open communication and to close it every time you want to communicate (read/write), and not to let it open all the time.
Turn of Screensaver and other Windowsstandby-options.

At the moment the dde communication is stable without freezing on one PC with windows XP pro. but other PCs hat the same problem, when I simulated the Flowdde-server.

Maybe we should try to find some information about DDE Technologie, at the moment it works fine, but I will post comments in future to solve it.
At the moment I'm busy with other things, but let's keep in touch.

greetings

danny

[JTOM]

Hello Danny,

Yes, as you mentioned DDE was the problem.  We are not using any mass flow controllers.  DDE is used only for data transfer between VB and labview applications. I found out that when mouse is moved all the threads get a boost.  This might be releasing the UI thread from hang condition.