In all synchronization situations, regardless of the simplicity or complexity of your studio configuration, the following rules apply:
There can only be one synchronization master.
The synchronization master sends time code information (synchronization signals) to one or more synchronization slaves.
Logic Pro is capable of acting as master or slave, as are many devices.
Important: In many (if not most) cases, you will need to manually set each synchronization-capable device—including Logic Pro itself—to act as master or slave. If you don’t do this, there will be multiple master devices in your system, which will result in synchronization errors.