B&R X20PS9400 PLC Module X20 PS 9400Supply for the bus controller, X2X Link and internal I O supply Feed and bus controller X2X Link supply electrically isolated Redundancy of bus controller X2X Link supply possible by operating multiple supply modules simultaneously Service interface (RS232) The supply module is used together with an X20 bus controller. It is equipped with a feed for the bus controller, the X2X Link and the internal I O supply.