1-5z The S5820X-28C provides two interface module expansion slots on its front panel, and filler panelsare installed on the slots when the switch is shipped. The above figure illustrates a switch with twoLSW1SP4P0 interface cards.z You can select one or two Interface Cards for your switch as needed. See Interface Cards on page1-17 for the Interface Cards supported by the S5820X-28C, and see Installing an Interface ModuleExpansion Card on page 3-15 for the installation of interface cards. See H3C S5820X & S5800Series Ethernet Switches Interface Cards User Manual for the detailed description of the interfacemodules.Rear PanelFigure 1-4 S5820X-28C rear panel(1) OAP card filler panel (2) Panel (do not remove it)(3) Grounding screw (4) Filler module (do not remove it)(5) Hot swappable power module 2 (6) Hot swappable power module 1(7) Hot swappable fan trayz The S5820X-28C provides two power module slots on its rear panel. Hot swappable power moduleslot 1 is empty when the switch is shipped, and hot swappable power module 2 is installed with afiller panel. The above figure illustrates a switch with two PSR300-12A AC power modules.z You can select one or two power modules for your switch as needed. See Hot Swappable PowerModules on page 1-13 for the power module models supported by the S5820X-28C, and seeInstalling a Power Module on page 3-12 for the installation of power modules. See H3CPSR300-12A & PSR300-12D1 Power Modules User Manual for the detailed description of thepower modules.z The S5820X-28C provides one OAP card slot on its rear panel, and a filler panel is installed on theslot when the switch is shipped. You can install an OAP card (firewall card, IPS card or accesscontroller module) on your switch as needed. For supported OAP card models, refer to OAP Cardon page 1-18; for how to install an OAP card, refer to Installing an OAP Card on page 3-18.