From the Tools tab of the Product Explorer, the I/Os button will open the I/O Studio. You can select multiple Products in the grid of the Product Explorer or within the Project Editor.
I/Os are used to populate the Inputs and Outputs on Visio and AutoCAD Schematic shapes/blocks. You can also add I/Os to a single Product when opened for edit.
I/Os consist of three parts:Terminal, Signal, and Label. You can manage your list of these via the I/Os settings in the Control Panel.
I/Os populate the SI Visio and AutoCAD Schematic shapes and blocks:
Within the Project Editor the feature is under Update->More->I/Os:
I/Os are also used to make Power over Ethernet (PoE) associations within a Project.