What is Wi-Fi password for the embedded controller Wi-Fi AP?

All controllers from the factory come with no default passwords for Wi-Fi AP, though there is a password for the web management interface. You can change password in the web interface of your controller and set up password for Wi-Fi AP. All communication is secured and encrypted. You can always perform a hardware reset and set the controller to factory default settings if you have physical's access tot he controller, but you have lost the password.