graph freeze

[setirli]

Hello everybody,

First I use LabWindows CVI 5.5 on Windows XP. 

I have a program wit a bar-graph. Every half minute gets my program netto weigts from a plant and show them on a XY-Graph.

My graph should show the last 96 data (see the attachment). These are 8 cycles and each time 12 datas.

I am storing these datas in an array "_dataArrayYValues[112]", (112 because of gaps between cycles).

In order to show the plots in different colours (green: OK, magenta: warning limit and red: security limit) I have a for-Loop and copy

each data into another array "_dataArrayVirtYValues[112]" (full with Zeros except one) and let them show one by one. After plotting is this array to be initialized.

If the graph is full, then the first cycle is removed (both from graph and array _dataArrayYValues[]) and the other seven cycles are moved to left.

So, the graph actually works perfect, but 1,5 months later after launching the program we sometimes have graph-freezing. The weight-datas are still showed correctly on the screen but you can see no changes on the graph. After a while (a few minutes) the graph works again and

shows even the old datas during freezing. We have also have a program crash once.

I suspect something is wrong with memory, maybe a memory overloading for a short period of time.

Has anyone of you similar experiences like that?

Any help would be appreciated..

Sait Etirli

[PeterAdelhardt]

Hi Sait,

it does indeed sound like it could be a memory-related issue. Have you ever monitored the amount of memory your program uses? Does it increase over the course of the 1.5 months? Could you possibly provide snippets of your code so that I could reproduce the problem here?

Thanks and best regards,

Peter

[setirli]

Hello Mr. Adelhard,

The problem is I can not reproduce the problem. The plant where the software is used to control, is very sensitive.

The machine is clock-controlled, that means every 70 mili-second comes a new clock. And there are two scales measuring and sending vial-weights to the programm. The scales are in a special protected place, where there is electro-static, pressure, humidity and so on... These are all factors which affect the system.

The machine works three shift.

In our simulation-enviroment I tested the program four days non-stop (24h) but didn't noticed any problem.

What I want to know is what could be the reason that a graph suddenly stops working and continious again after a while(it even shows data came during freezing)?

Regards

Sait Etirli, Switzerland

[PeterAdelhardt]

Hello Mr. Etirli,

I am not aware of any reason that might cause this behavior. Do you have other processes running on the target machine that might influence the program?

What kind of time lag do you observe, i.e. how long does the program run without updating the graph? Is the computer responsive during that time?

Could you provide me with some code so I could check for potential issues?

Thanks and best regards,

Peter

[setirli]

Hallo Mr.  Adelhardt,

About 10 minutes the program runs without updating the graph. But the rest of the program still works, for instance I can print the graph or the weight-values are displayed on the main screen. But anything blocks the graph somehow.

I can send you a part of coding, but the comments in the coding is in german. I assume it is no problem for you.

Thank you and best regards

Sait Etirli

[LuisG]

Hello Sait,

There was a bug in all versions of CVI up until CVI 8.1 whereby a user interface could become unresponsive after approximately 49 days. This was caused a by an internal timer rollover problem (49.7 days happens to be the amount of time necessary for the number of milliseconds to exceed a 32-bit integer).

Since your report mentions 1.5 months, in all likelihood this is the bug that you're running into.

This bug was fixed in CVI 8.1.1, so to fix this, you'll have to download a newer version of the CVI Run-Time Engine and install it in your customer's machine.

One note of caution: keep in mind that you'd be moving from version 5.5 to version 9.0, which is a very, very large jump. The run-time engine is supposed to be backward compatible, but skipping this many versions ahead can still be risky. Please make sure to test your application thoroughly before deploying this version.

Luis

[setirli]

Hello Luis,

Thank you for your answer. But I don't think we have the problem you've described. Because the program is still responsive but only the graph is not updated. And after a while say ca. 10 minutes it works properly again and shows even old datas came when it was not working.

I am sure the newest version of LabWindows is better but you know you cannot always change a software version of a customer. They have machines ald hardware which is not going to work under the newest version. So our attempts to change to Labwindows 8.1 in last summer failed on hardware. Well, we must keep the existing version.

Best regards

Sait Etirli

[PeterAdelhardt]

Hi Mr. Etirli,

since you do not want to try using a newer Runtime-Engine, would it be possible to provide us with your project's code? We might be able to reproduce the error (there must be some sort of timer rollover) internally.

Thanks and best regards,

Peter