Card version. The Novastar Multifunction Card MFN300 is a multifunction card which combines a variety of functions into one card. It can be easily added to the screen setup at any desired position within the ethernet screen connection. The MFN300 Multifunction card allows you to add a variety of functions such as: sensor inputs to connect light or temperature sensors to the screen setup but it also has eight on-board relay contacts, RS 232 connection and audio output.