Help Needed: Video Loss during Multiple USB3 Camera Simultaneous Acquisition

[tcadas]

I am using three Basler Ace industrial USB3 cameras to simultaneously capture images at 1280x960 resolution. When the vi is started all three cameras capture streaming images. However, after sometime, one of the camera stops showing streaming images and starts to show an image with diagonal gradient gray bars (see attached). If left running, after sometime, a second camera does the same. If the vi is stopped and restarted after a few minutes, all three cameras function normally but then the above problem occurs again after a while. What is the cause of this video loss? What could be a resolution of this issue? I have attached a snapshot of the video loss image and the relevant section of the code for parallel image acquisition. I have tried two different version of the code, both giving same problem.

Thank you.

[elcalverado]

Hi tcadas,

That image with the diagonal gray bars is one of the test images on the Basler camera. I've used Basler Ace camera for a long time and I've never seen one switch to the test image automatically. Is there anywhere in your code that you are changing camera attributes? 

What happens if you grab from one camera in NI MAX? If you leave it long enough, does it also switch to the test image?

Lastly, can you post your actual VI?

-Jordan

[tcadas]

Hi Jordan,

Thanks for responding. 

I am not switching any camera configuration in runtime. Only changes that have been made to the camera settings are the shutter speed (exposure time) and the resolution. I did that in MAX and saved the settings before running the VI.

 The three cameras are as follows:

·      One basler ace aca2000-165uc

·      Two basler ace acA1920-150uc

I have set the resolution to 1280 by 960, and the exposure time 1000 for all three cameras in Max. No changes to the camera settings is done in runtime. Attached is the vi. 

[Bob_Schor]

Several (six?) years ago, we had a Project that used 24 Axis cameras capturing 5-10 second videos (at 10 fps) of behavioral events signalled by channel-specific signals.  The cameras used TCP/IP, and we were able to record from all 24 cameras and capture videos from them (each station produced 10-30 videos in a 2 hour recording session).

We attempted to "migrate" this system for a colleague who had 6 Axis cameras running over USB, and expected it would be "no big deal".  As I recall, we discovered there was something funny about cameras on a USB channel compared to TCP/IP -- as I recall, we couldn't do more than 2-3 cameras (this was the finding of a one-day "field-trip" to a site several hour's drive away -- I don't know if this got resolved, but certainly when we plugged in the Cameras, we didn't get the speed we were expecting based on our experience with the Ethernet-interface cameras.

Bob Schor