Abstract: A communication controller for protecting data, stored in a printer or other printing device connectable to a first network, from unauthorized access including: an external communication device for communicating with an external station through a second network; an internal communication device for receiving operation related data relating to the operation of the printer; and a controller for allowing the external communication device to communicate the operation related data to the external station only when the printing apparatus is functionally disconnected from the first network. A sensor is also provided to sense whether the printer is off or otherwise functionally disconnected from the first network. A switch permits real-time testing of the printer while it is connected to the first network. This switch automatically resets when not pushed to prevent accidental external access to the printer while it is connected to the first network.