This Diagram also called the is used to manage all the NSTX-U interfaces. It includes all the subsystems extracted from the WBS starting with PFCs in the top left corner working through the Test Cell in the bottom right. The two letter represent the interface types: Mechanical (Me), Thermal (Th), Plasma/Eddy/Halo Current (Pe), Vacuum (Va), Gas/Fluid (Gf), Signal (Si), Software (Sw), Electrical Power (Ep).