Status Bar
There is a bar at the bottom of the main window that has three text boxes.

Status Message
The left text box is a status area that has warnings, errors, and informative messages. It is cleared by clicking it, by clicking an entry in the navigation pane, or by clicking File > New.

Connection Status
The middle text box indicates whether the GUI is connected to a device or not. This box has the two values 'Connected' or 'Not Connected'.

Connection Port Identifier
The right text box shows the serial port used to connect to the device.
If there is no connection then this text box is empty.