When you open Logic Pro, it automatically detects any powered Mackie Control unit that is connected to your system. You can use the Mackie Control immediately—with the default settings—or you can customize its settings, as described in Basic Control Surface Setup, and Customizing Controller Assignments.
Once set up, you can use the Mackie Control to control Logic Pro in the following ways, or perhaps take an alternate approach that best meets your working preferences.
With your project open in the Arrange window, select the channel strips you want to control by pressing the Fader Bank buttons on the Mackie Control.
See Mackie Control: Fader Bank Zone for more information.
Select the parameters you want to edit, and whether you want to edit multiple channels (Mixer view) or a single channel (Channel view), using the Assignment buttons.
See Mackie Control: Assignment Zone for more information.
Start playback, and move the playhead to the position where you want to work, using the Mackie Control transport buttons and Jog Wheel.
See Mackie Control: Transport Zone and Mackie Control: Jog/Scrub Wheel Zone for more information.
Edit the project with the channel strip controls.
See Mackie Control: Channel Strip Controls for more information.