Thanks, @kerel!
If you like to have a dedicated controller hardware (e.g. a separate RasPi where your rotator control box is connected to) you need to run a rotctld service on this device. You may want to start it something like this:
rotctld -m 602 -r /dev/LVBTracker -s 9600 0.0.0.0:4355
You can add -vvvvv to get full verbose debug output on a commandline. Once you‘re satisfied with your configuration add rotctld as a service started on system boot.