Motorola MG7540 User Manual page 33

You can enable one or more Guest Networks to let friends use your Internet
connection without giving them access to other devices on your network.
To set up a Guest Network, first log into the Configuration Manager as described
in chapter 4. In summary, you type 192.168.0.1 in the address bar of your
browser, go to that address, enter the Username admin and Password motorola,
then click the Login button.
This will bring you to the Basic Status and Settings page. Click the Advanced
button in the upper right. This will bring you to the Status  Software page.
Hover over the Wireless menu item, and select the Guest submenu: