Interface devices
An interface device is an externally-facing piece of hardware that interacts with an actor, another subsystem or a different system entirely. One interface device on a System Architecture Diagram can represent a group of interface devices in the real world. As an interface device is a black box, use a subsystem if you need to describe any internal structures.
Use the 
icon on the System Architecture Diagram tab to add an interface device to the diagram, or you can drag an interface device from the dictionary.
icon on the System Architecture Diagram tab to add an interface device to the diagram, or you can drag an interface device from the dictionary.When you have added an interface device, you can change it both via the diagram using the interface device Property pages and the context menu.
To detail the interface in which the device operates, attach an interface device type to the new interface device through the Options tab of its Property pages.
Actors link to the interface device through external connectors. Point-to-point connections link interface devices with subsystems and other components on the diagram.
Use the 
icon on the System Architecture Diagram tool bar to link items to an interface device.
icon on the System Architecture Diagram tool bar to link items to an interface device.