Understanding the Synchronization Protocols

Logic Pro supports the following synchronization protocols:

• MIDI Time Code (MTC): Translation of a SMPTE time code signal into a MIDI standard time code signal.
• MIDI Clock: Short MIDI message for clock signals. It is used to provide a timing pulse between MIDI devices. Logic Pro can send MIDI Clock signals to synchronize external devices. It cannot receive MIDI Clock synchronization signals.
• SMPTE time code: An audio signal that is translated into MTC by some MIDI interfaces, such as the Unitor8.
• Word Clock: This is a signal that is carried by all digital audio interface formats (ADAT, FireWire Audio, S/P-DIF, AES-EBU, T-DIF). It is used to maintain the timing integrity of sample words in audio signals that are transmitted digitally between Logic Pro and external hardware or software.
• ReWire: Logic Pro can act as a ReWire host. It acts as the master synchronization source for ReWire-enabled applications such as Reason and Ableton Live. This chapter does not cover the use of Logic Pro as a ReWire host (see Working with ReWire Applications).

  Tip: Logic Pro also supports manual or “human” sync, when slaved. This is not a synchronization protocol per se, but enables Logic Pro to follow tempo changes in real time. As an example, it could chase a live drummer. See Using the Tempo Interpreter Window.