Human User Interface Protocol
Human User Interface Protocol is a proprietary MIDI communications protocol for interfacing between a hardware audio control surface and digital audio workstation software. It was first created by Mackie and Digidesign in 1997 for use with Pro Tools, and is now part of the Mackie Control Universal protocol.
Functionality
HUI protocol allows a digital audio workstation and a connected hardware control surface to exchange MIDI signals that synchronize the states of their sliders, buttons, wheels, and displays. The user can write console automation which can then be seen in the DAW. It includes support for 10-bit/1,024 discrete values.History
The HUI protocol was created jointly by Mackie and Digidesign in 1997 for Mackie's Human User Interface, the first non-Digidesign hardware control surface for Digidesign’s Pro Tools. It was subsequently implemented by hardware controllers from manufacturers such as Solid State Logic, Yamaha, TASCAM, and Novation.By the time Mackie introduced the Baby HUI in August 2002, the protocol was also supported by DAWs including Digital Performer and Nuendo, making them cross-compatible with HUI-compatible hardware controllers. Other DAWs to support HUI protocol include Logic Pro, REAPER, and Cakewalk Sonar.