MXId changes on a few OAK-D cameras

KevinGeorge

Hello, we're finding for some of the Luxonis OAK-D cameras, that the output of depthai.getMxId() is changing over time. We thought this would be a unique ID and never change for the same camera. Anyone experienced this or have suggestions on how we could troubleshoot this further?

jakaskerl

HI KevinGeorge
MXID should not change.. Can you give some more info (which devices, which depthai versions,..)

Thanks,
Jaka

KevinGeorge

Device: Luxonis OAK-D Pro PoE

Depthai version: 2.24.0.0 over python

A particular example: The output of getMxId was initially 18443010712F8E0E00 and changed to 1844301021775C0F00 when I restarted the software talking to it

Please let me know if there's any more info I can collect 🙂

jakaskerl

KevinGeorge
Doesn't change for me.. Tried printing device.getMxID() on multiple runs with OAK-D S2 PRO POE. MXID stays the same. Ver. 2.24

Thanks,
Jaka

KevinGeorge

Is it possible that it only changes over time? We're seeing this on multiple cameras.

If there's no obvious answers, do you have any suggestions on other ways to uniquely identify a camera?

jakaskerl

KevinGeorge
MXID should be constant. Will check tomorrow what can be done. AFAIK it should not change under any circumstances.

Thanks,
Jaka

Luxonis-Alex

Hi @KevinGeorge , I can confirm that the MXID is really not expected to change.
I also looked for bit errors between the 2 numbers (hex), but there are many differences:
18443010712F8E0E00
1844301021775C0F00
so I think the software started talking to a different OAK device on the same network, after it was ran again.
I can also find both these MXIDs in our factory calibration logs.

How is the application connecting to the device (DeviceInfo), is it based on the IP address? If this is the case and a DHCP server is present on the network, it could happen it may assign a previous IP address to a different device.

KevinGeorge

Thanks for confirming that the the cameras are different from your factory calibration, this give me much more confidence that the camera is indeed different. I checked the other camera on the network(we use the IP address) and it never changed it's serial 18443010E1E6960F00

The only logical explanation that remains is that our software doesn't shut down on a hardware disconnect sometimes and holds on to a stale MXId. I'll go verify this theory. Thank you for the assistance 🙂