How to solve an incorrect or changed identification when connecting 3D printers
When you face a situation when multiple 3D printers are connected to one Raspberry Pi, a single-board computer, or a PC, and after the computer restarts, it unexpectedly changes its identification, it means that your printers are reporting identical serial numbers to the computer, or even don't report them at all.
Don't worry - we have the solution for you.
Connect to the 3DPrinterOS Client situated on the computer in question. Type the computer's IP address together with a port in your browser.
If your 3DPrinterOS Client is installed on a Raspberry Pi, you can find the RPI's IP address here. For example, "https://10.0.1.10" or "http://10.0.1.10" or just "10.0.1.10"
If your 3DPrinterOS Client is installed on a local computer - type "http://127.0.0.1:8008/"
Select "Settings" in the upper left corner of the browser window.
Select "Edit settings file" in the upper left corner of the dialog box
Find the key "backward_compatible_serials" and change the value to false. The resulting string should be "backward_compatible_serials": false,
Find the key "no_empty_serials" and change the value to true. The resulting string should be "no_empty_serials": true,
Click the "Save" button
Restart your 3DPrinterOS Client (make sure that you have nothing printing with this 3DPrinterOS Client - a printing job will be failed in the case of restart)
If you have Raspberry Pi or a single-board computer - Quit the Client (it will be autostarted). Or you could just reboot the RPI.
If you have Windows, Ubuntu, or macOS computer - Quit the Client and start it again.