Connexium switch applies default port / operation settings based on Dip Switch positions set and it over rides any custom configuration done during next power cycle. So to free up port for use assigned to coupling and to turn OFF operation of Ring/Coupling Network , a custom configuration has to be applied to switch.Makes sure to put dip switch both RM & Standby in ON position and do settings for Hiper Ring redundancy etc and Operation to OFF for ring networking coupling and coupling port can be left at default. Doing this will free up coupling port to connect any devices.