Computers you want to manage can also be entered by manually. You can select

Computer > Add computer

from the menu, click the Add computer toolbar button, or right-click on the SignPlus object on top of the tree and select Add computer from the popup menu. A dialog will appear where you can specify the IP name or address of the computer you want to manage. That computer will be added to the managed objects tree.

See Specifying the computer to monitor.