The I/O window allows you to map which inputs and outputs in Pro Tools correlate to the hardwire inputs and outputs, allowing you to get sound in and out of Pro Tools.
1. The I/O window is accessed by going Setup → I/O.
The I/O window contains all the input and output routing as well as the bus routing. It’s displayed as a grid with the available inputs or outputs across the top and the path, which go to the channels along the side.
Clicking the down arrow on a path will reveal its subpath.
You can change a paths name here by double clicking the name.
Note — Output paths may not overlap, however several buses can be mapped to the same output.
E.g. Stereo and 5.1 Bus mapped to the same 5.1 Output.