There is very little difference between using Alert! to diagnose the machine it is running on and using it to diagnose some other machine on the network. This assumes, of course, that the necessary installation (as covered in “Installation”) has been completed.
To diagnose a networked machine, use the Network button in the Alert! window or the Via Network item in the Diagnose menu. This will give you a dialog that allows you to select the Alert! Responder on the machine to be diagnosed.