Bitwig's Alexander Ewald walks through how Bitwig Studio connects with modular and semi-modular synthesizers via a CV or DC-coupled audio interface. The HW CV Instrument device lets you play and control Eurorack modules directly from the DAW, and Bitwig can auto-tune Eurorack oscillators in one click.
The connection also runs in the other direction. The CV In modulator lets your modules send control voltage into Bitwig to modulate instrument devices and plugins, effectively turning your hardware into a modulation source inside the DAW.