Try page 90 of the MPC manual:
https://cdn.inmusicbrands.com/akai/M22D ... 2.11.7.pdfSpecifically:
The settings on this screen determine how your MPC hardware uses and synchronizes with connected USB and MIDI devices.
Input Ports: This displays all available MIDI input ports in a list. Double-tap the keyboard icon to rename a port
to a custom name.
When Global is enabled, MIDI data from this port will always go to the current track.
When Control is enabled, MIDI data from this port will be sent to MIDI Learn.
When Track is enabled, this MIDI port will appear in the list of available MIDI Inputs. Click the reset arrow to reset the MDI Port settings.
Output Ports: This displays all available MIDI output ports in a list. Double-tap the keyboard icon to rename a port
to a custom name.
When Sync is enabled, the MIDI output port will send MIDI sync messages according to the
type set under Sync Send, below.
When Track is enabled, this MIDI port will appear in the list of available track
MIDI outputs. Click the reset arrow to reset the MDI Port settings