The Morningstar units can do a lot of things, which can make configuring them through the Morningstar Editor a bit overwhelming.
If you want to achieve something you might think would be simple, like displaying the name of the Rackspaces or Variations or Songs or Songparts on the screens, that can actually get very complex.
What pianopaul wrote above is one way to approach it. That’s how the Morningstar units are designed to work.
I wrote a GP extension some time back with the intention of making it work more easily and flexibly with GP. My suggestion would be to look at this thread: Morningstar MC8 / MC6 / MC6 Pro Extension
It requires a little bit of setup, but if you want to give it a try and have any questions just ask.