LabView crashes at parallel image acquisition and processing

[freaklamarsch]

Hi,
in my program I have two loops. One Loop is grabbing an image from a IEEE 1394 camera, analyzing it and putting the image with additional information into a cluster. This cluster is then published to the other loop using a notifier.

The other loop is running independend from the acquisition loop and just reading (at a predefined rate) the current status of the notifier and saving the information to the hard disk.

This program runs fine for a while (using 10% CPU and 5% RAM) and then crashes. (LabView stops responding, uses 100% CPU and I have to kill it via task manager)

I think this problem is caused by saving the image to disk while the acquisiion loop is overwriting the image in the cluster.
Could this be?
And how can I prevent this from happening? I want o have two independend tasks, so a semaphore is not a real option.

Thanks,
FReAK La Marsch

[freaklamarsch]

Ok, I solved it.
The problem was not the race condition between saving and grabbing the images, it was the Display Image Control (which is recommended by NI http://zone.ni.com/devzone/conceptd.nsf/webmain/0E9074660DFFA7A38625685E007F5771 ) I used for checking if the camera is working properly while saving.

If I update the image display with a frequency of 25 fps or higher, the Display Control starts to behave strange and is causing the crashes.
I rotate the images and give them an overlay before I display them, but on the display, there are sometimes images which are not rotated and don't have the overlay, so I wonder where these images come from. And sometimes the Display is showing no image at all.

Now I use the WindDraw VI for displaying the images and every thing runs fine. No flickering, no strange images, no crashes.
So I wonder why NI recommends this faulty VI.

I am using Labview 7.1, NI-IMAQ 3.0.3, NI-IMAQ for IEEE1394 2.0.1 and IMAQ Vision 7.0.0

Message Edited by freaklamarsch on 03-23-2006 11:24 AM