Bug: Windows 7 DLL call to turn off monitor message crashes LabVIEW 10.0f2

[DavidJCrawford]

Hi,

I wanted to log this bug on the forum. I have already logged this with NI UK Support: CAR# 286873

I was trying to find a way to turn off a laptop lcd monitor during measurements. I was trying to replicate this

http://codereflect.com/2009/04/03/how-to-programmatically-turn-onoff-your-monitor/

which uses windows messaging.

I found the attached Monitor-1.vi somewhere on the forum that seems to do the above. However when I run the VI it crashes LabVIEW 10.f2 on Windows 7 32-bit.

cheers

David

[cosmin]

If you delete la last frame, and replace "1" with "2" (the last input of DLL) it's working (i'm also in win7, labview 2010)

[DavidJCrawford]

Hi cosmin,

Thats strange I just tried what you suggested but it still kills my LabVIEW. I admit the monitor did switch off however when it came back my LabVIEW was gone.

Have you installed LabVIEW 2010 SP1 or still running the original install of LabVIEW without any patches?

Many thanks for pitching in.

David

[cosmin]

Hi David,

I have 2010f4

[cosmin · Accepted solution]

change calling convention to stdcall

[DavidJCrawford]

Hi Cosmin,

That was it! Thank you so much!

I will let NI UK support that you identified the issue and get them to close the CAR.

cheers

David