VXS stands for VMEbus Switched Serial Standard. The standard is VITA 41. VXS has the same form factor as standard VME boards, but uses a different type of P0 connector and a different electrical interface. The VXS specification defines 2 types of boards: Payload cards and Switch cards. Payload cards are standard VME64x boards with a new PO connector for serial links. Switch cards are not backward compatible with the legacy VMEbus standard via P1 and P2 connectors. VXS Backplanes may operate in a number of configurations; Star, Dual-Star, Mesh, or Daisy-Chain. VXS supports InfiniBand bus, Serial RapidIO, Gigabit Ethernet, and PCI Express Bus.