PIN is a security token. In order for the rig to reach the server, the PIN in the configuration file must match the PIN in the user profile in your account. By default, the PIN in both places is set to "12345".
How to connect rig with admin panel?
As you know, in order to associate mining rigs with the MinerOS control panel, an e-mail address in the configuration file is enough. It is very comfortable. You can download a personalized image from your personal account (which already contains your authorization e-mail) and burn it immediately to all rigs without changing anything in the settings. The name of the rig and other fields can be changed later from the control panel.
So why do you need a PIN?
If an attacker recognizes your authorization e-mail, he can add his rigs to your control panel by entering an e-mail in the config. The problem is not dangerous, and extremely rare, but we decided to protect ourselves from this situation by adding a PIN check. An attacker must also additionally know your PIN in order to do his dirty business.
How to change PIN?