
MIDI Inputs settings in Logic Pro for Mac
When Enable Complete Features is selected in Advanced settings, MIDI Inputs settings are available.

Each row in the list represents a connected MIDI device on your computer (wired or wireless) recognized by Core MIDI. Logic Pro can receive MIDI signals from any of those MIDI devices, referred to as MIDI In ports. If a MIDI device has multiple MIDI ports, all ports are listed separately. Only the ports with a selected checkbox in that list are available in the MIDI In Port pop-up menu of the Track inspector in instrument tracks and external MIDI tracks. MIDI signals from only those ports can be recorded. See Edit track parameters.
Wired or wireless devices: Receive MIDI from any hardware MIDI controller that is connected to your computer via USB or Bluetooth.
Logic Pro Virtual In: Receive MIDI via this internal bus from any app on your computer with Logic Pro Virtual In selected as its MIDI output.
IAC Driver Bus 1: Receive MIDI via this internal bus from any app on your computer with this device selected as its MIDI output (requires configuration in the Audio MIDI Setup app).
Network Session 1: Receive MIDI from any app on your network with this device selected as its MIDI output (requires configuration in the Audio MIDI Setup app).
Auto Sampler: This option is visible if an audio track in your project has the Auto Sampler plug-in inserted in an Audio Effect slot.
Tip: Only select the MIDI In ports representing the MIDI controllers you use for recording. Deselect any other MIDI In ports to avoid receiving and recording unwanted MIDI events.
On checkbox: Use these checkboxes to deactivate (or reactivate) a MIDI In port. When a port is deactivated, you can’t record from that MIDI source anymore.
Device or Port field: Lists the name of each available MIDI device or port. If a MIDI device has been removed or is inactive (grayed out), you can delete it by selecting that field and pressing the Delete key.
Unselected devices and ports are not displayed in the MIDI Input pop-up menu of a software instrument track’s Track inspector. See Edit track parameters.
Note: The MIDI Activity display in the LCD shows incoming MIDI messages of all MIDI In ports regardless of whether they are selected in this window. See Monitor and reset MIDI events.
Sometimes a hardware device using the same MIDI In port to communicate with both Logic Pro and other software applications may send large streams of MIDI data, causing playback artifacts or corrupted projects. For example, an audio interface may use a virtual USB MIDI port to send a continuous stream of MIDI sysex data to both its mixer software and Logic Pro. If you are experiencing these issues when using Logic Pro with hardware devices or other applications, MIDI Inputs settings can be used to deactivate specific MIDI In ports in use by other software applications.
To determine whether these issues are due to large MIDI data streams, and to determine which MIDI In port the data is being transmitted on, you can use a MIDI monitoring application (free MIDI monitoring applications are available on the Internet). You can also refer to the documentation for your MIDI hardware device to see on which ports it sends sysex data.