I'm a little confused by your question. The RC210 is the controller, so I don't know how you are unplugging the RC210 from the controller. Maybe you are talking about the cable from the connector on the back of the controller's enclosure to the RC210 circuit board.
Physical security is kinda up to you. Install all of the screws in the cover of the controller's enclosure. Install the controller in a locked cabinet. Install the cabinet in a locked room. That's how it's typically done.