CPU usage rises in LabVIEW executable

[transfererror]

I probably solved the problem here as well.

After copying the block diagram into a blank vi (Labview 2012) now everything works fine for the last 24h (new record).

Best regards

transfererror

[transfererror]

Nope, no solution, here.

After 36 h cpu load rose again in the moment of connecting remotely (with resolution change).

Mass compiling didn't help either.

[transfererror]

Update of status quo:

I'm running three monitoring vi's, originally written in Labview 7.1 an 8.2.1, on a Windows 8.1 PC in Labview 2012. I have access to this computer only via remote software (remote desktop or teamviewer).

I found out that each program causes the CPU load problem when switching the desktop resolution.

I no longer think, that it has something to do with remote access software. With teamviewer one can easily change the resolution and this change definitely triggers the error.

The main problem is, that I can't find any reproducible circumstances.

This is, what happend today:

- connected remotely to monitoring PC (in this moment the desktop resolution is set)

- CPU high

- I was able to stop all running vis (this is not always possible)

- CPU high

- closed all vis (this is not always possible) but didn't close Labview

- CPU low

- started "CPU Usage LV821.vi" (see attachment)

- CPU low

- changed teamviewer resolution

- CPU high

- stopped "CPU Usage LV821.vi"

- CPU high

- closed "CPU Usage LV821.vi"

- CPU low

- started "CPU Usage LV821.vi" and changed resolution several times.

- sometime CPU high, sometimes CPU low

I could not get "CPU high" with deactivated waveform chart!

But I was watching the CPU load of the labview thread (with task manager) while switching the resolution. Everytime I do so, CPU load rises a little bit for a short moment. Whatever is running in this moment, I think that this module causes the error (graphic memory overflow?)

Any ideas

transfererror

[transfererror]

Hello,

I figured out something new:

I'm connecting to my remote (measuring) PC via another desktop PC or laptop. When I do so, I normally use the the full resolution of the client computer (1280*1024 or 1376*768, respectively).

Now I can see (with the help of a vi, running on the measuring PC, which I can see via the labview web server), that after logging off of the measuring PC, that the resolution switches back to 1024*768. This seems to be some kind of a default resolution as long as nobody's watching.

This means: everytime I connect or disconnect to or from the measuring PC I cause a change of resolution as long as I do not use the poor resolution of 1024*768.

And as I meantioned above: the changes of resolution are causing my high CPU load problem.

transfererror

[xavvvv]

Hi transfererror,

It is normal that you experience a CPU spike when changing the screen resolution if you are remoting in. I just tested your VI and am seeing small spikes. However, I could not keep the CPU stay high for more than a second or so (which is expected):

At this point, could you send a screenshot of your front panel, just to see how long it stays high?

[mberetta]

I'm able to replicate the failure even running labview code (not just exe) after resizing the VM Fusion 6.0.2 window (which act like screen resize).

Please note cpu stuck to max usage till any "menu" droplist is display. As soon as close the "menu" droplist, application request again max cpu usage:

I could share full labview code to NI dev team if needed. Please contact me via private email for detail.

Thanks and Best Regards,

Marco.

[mberetta]

Please also note once the issue is detected, the cpu stuck at max even with NO vi open/running (with same exception related to "menu" droplist showed or not):

[transfererror]

@mberetta: thanks for confirming the error.

@xaww: in the last 36 h the error didn't occur. But as mberetta said: the high cpu load doesn't dissappear until the user closes all VIs (the thing with menu droplist is new for me. And I haven't tested it yet.). In rare cases I have to kill Labview via the task manager.

transfererror

[transfererror]

Now CPU high load error occured again, and I was able to confirm mberetta's observation:

The high CPU load drops down for the time the droplist of the menu bar is visible. Strange.

[transfererror]

Finally I'm happy: with Labview 2013 I don't have this problem anymore 🙂