avi Write2 function "freezes" computer

[rohrs2]

I am trying to run four cameras through the PCIe-8244 USB3.0 frame grabber and collect videos from all of them independently. This is proving to be an extremely difficult task. (LabVIEW 2013)

So far I have IMAQdx working fine for two cameras to display to the front panel. However as soon as I try to record, I cannot press any other controls on the front panel, which makes starting the recording of other cameras impossible, below is a pic of what is running. I have tried putting the avi Write2 function in timed loops or just with timers and in either case I can only gather one video at a time. However the cameras are still running in their independent loops without an issue. The timed loops shown are initiated through an event structure by a record button in the camera's independent capture loop.

Attached is the code in question, please ignore my attempts at debugging indicators.

I do plan on expanding this to the full four cameras that PCIe-8244 supports.

[BlueCheese · Accepted solution]

I might guess that running the AVI code within the event loop causes the code to run withing the UI thread, preventing access to the controls while the code executes.

[rohrs2]

It seems you were right! I removed the event structure and replaced it with a while loop that waits for record control to be TRUE before moving on to the avi Write2 timed loop.

Thanks for your help!