Nerian Support Forum

Hello,
I'm working with libvisiontransfer in c++ for a vision project and have suddenly encountered an issue with my SceneScan Pro (monochrome). It has begun repeatedly disconnecting and then immediately attempting to reconnect, which has dropped the framerate to below 1fps. As a note, I am not using jumbo frames, but I am using a 5Gb/s ethernet to handle the increased volume.

I have attempted the following quick fixes:
Reboot the device, via unplugging and maintenance view of the web interface.
Connecting different ethernet cables (all tested to work at 5Gb/s) from the box to the switch I was using.
Connecting the device directly to my PC.
Visual check to ensure camera settings are identical between left and right cameras.

I would appreciate any assistance that can be provided on this issue. I'm completely stumped by this.

Update to the issue:
After leaving the system off for a few hours and returning to it later, the device is now unable to connect to NVCOM or my c++ program. However, in the device's web interface, the preview framerate for the individual cameras and the disparity map have both returned to their normal 30fps.

This seems to be a problem with the network connectivity. Very likely there is a high amount of packet loss on the network. This can be caused by the following:

• * A network interface with very little buffer memory (often found in laptops)
  * A switch on the network that can't handle the high throughput and drops packets (we recommend the Netgear ProSafe line)
  * Other high-bandwidth communication happening on the same 1-Gigabit link (e.g. 2 SceneScans)
  * Low-quality Ethernet cables

As a work-around you can switch from using the UDP protocol to TCP in the network settings. TCP is better able to cope with packet loss. However, this will likely have an effect on the achievable frame rate due to the required re-transmissions and the the possible throttling of the sending rate by TCP.

Thank you for your quick response to my issue.

As of now, I've managed to fix the issue just by doing a factory reset of the SceneScan and re-uploading it's original settings. I am beginning to suspect that the issue was related to overheating from running the system continuously for too long a time during development and testing, as the issues have stopped entirely.

We are currently not aware of any network issues in relation to thermal causes. Please let me know when you are experiencing similar problems again.