Hi, I am working with OAK-D-PoE for quite sometime now. My setup include two cameras connected with 50m cables with a PoE switch. At random I encounter three "RuntimeError" which are following: * RuntimeError: Failed to connect to device, error message: X_LINK_DEVICE_NOT_FOUND * RuntimeError: Cannot find any device with given deviceInfo * RuntimeError: Communication exception - possible device error/misconfiguration. Original message 'Couldn't read data from stream: 'detection' (X_LINK_ERROR)' I am continuously encountering these errors. For now I have added exception handling and re-connection with some time delay. I followed the troubleshoot guide, but unfortunately the errors are still there. Can anyone help me in troubleshooting this problem?

@"InzamamAnwar"#p7608 does it happen with shorter cables as well? You might want to [increase delays](https://docs.luxonis.com/projects/hardware/en/latest/pages/guides/getting-started-with-poe.html#special-network-equipment).

@"InzamamAnwar"#p7647 Please do try it as well, as it might help.

OAK-D-PoE Connection Errors, RuntimeError, X_LINK_ERROR, X_LINK_DEVICE_NOT_FOUND

InzamamAnwar

Hi,

I am working with OAK-D-PoE for quite sometime now. My setup include two cameras connected with 50m cables with a PoE switch. At random I encounter three "RuntimeError" which are following:

RuntimeError: Failed to connect to device, error message: X_LINK_DEVICE_NOT_FOUND
RuntimeError: Cannot find any device with given deviceInfo
RuntimeError: Communication exception - possible device error/misconfiguration. Original message 'Couldn't read data from stream: 'detection' (X_LINK_ERROR)'

I am continuously encountering these errors. For now I have added exception handling and re-connection with some time delay. I followed the troubleshoot guide, but unfortunately the errors are still there.

Can anyone help me in troubleshooting this problem?

domgs

I had the same issues with my camera, because my dhcp setting were wrong.

Does your router have dhcp? Can you ping your cameras and are they in the right network?

If this is all correctly set up, keep in mind, that the OAK-D does need some time to restart (my OAK does sometimes need up to 30 seconds and then it also takes some time to get the dynamic ip).

InzamamAnwar

I have assigned static IPs to camera to overcome this. The camera works perfect for hours but suddenly they stop working. When I restart the code immediately, It gives me one of LINK errors. And after waiting for sometime they start working again. Now in exception handling I wait for cool off period and try to reconnect the cameras.

domgs

Okay now I understood your Problem correctly.

So did you already try recording the temperature data from the camera?

InzamamAnwar

No I don't have any idea about temperature data. Is there any correlation ?

erik

InzamamAnwar does it happen with shorter cables as well? You might want to increase delays.

domgs

I'm also not sure, but maybe it's getting too hot.

I would try recording the temperature data as a first attempt.

For recording the data have a look at: https://docs.luxonis.com/projects/api/en/latest/samples/SystemLogger/system_information/

InzamamAnwar

I haven't tested with shorter cables for longer times. I will increase delay as you suggested

erik

InzamamAnwar Please do try it as well, as it might help.

InzamamAnwar

erik What are the maximum lengths of cables have you tested internally?

InzamamAnwar

erik After increasing the delay as you suggested, I am not encountering the LINK errors. Rather, the stream is stopped randomly

erik

Hi InzamamAnwar ,
Have you tried the shorter cables as well? We did try with 15m (longest in our office) and it worked as expected. Also, are you using cat6 cable?
Thanks, Erik

InzamamAnwar

Following are the steps I took to make cameras work with ~30m cables:

Update the depthai: This was rather a simple step but I was hesitant to upgrade. Though I have regularly updated the firmware. Up-gradation from 2.19 to 2.21.
I was getting raw frames from the color camera which may trigger CPU to 100% usage over time. This may result in halting of camera. Changed this pipeline to use encoded frame and it worked like a charm.

@erik, Though, I don't know whether my deductions are correct or not, However, I would like to know what do you think?

Thanks!