I misread the list of compatable models for the serial connection (stupidly read Pro as Plus - senior moment!) and bought 2 serial cables. One for the 5 Plus and one for the PrintMill. After getting it all installed in the Plus, having cut down the supplied cable, changed the end to a USB printer style socket and fitted it all inside the box I went to change it over from USB to serial… no option!
Ah well, lesson learned. @Collin @CREALITYSTORE is there any plan in the future to add the Ender-5 Plus to the models that can be serially connected?
Cheers
Poida