The system controller slot is slot 1 of the chassis and is a 2-Link configuration system slot as defined by the CompactPCI Express and PXI Express specifications. The chassis includes three system controller expansion slots for system controller modules that are wider than one slot. These slots allow the system controller to expand to the left to prevent the system controller from using peripheral slots.

The backplane connects the system slot to two PCI Express switches using a Gen-3 x8 link and a Gen-3 x16 link. The two PCIe switches distribute PCIe links to the peripheral slots and to a PCIe-to-PCI bridge to provide a PCI bus to the hybrid peripheral slots.

System slot link 1 is a Gen-3 x8 PCI Express link to the first PCI Express switch, providing a nominal bandwidth of 8 GB/s (single direction) between the system controller and PCI Express switch 1. PXI Express peripheral slots 2-10 are connected to PCI Express switch 1 with Gen-3 x8 PCI Express links and are downstream of system slot link 1.

System slot link 2 is a Gen-3 x16 PCI Express link to the second PCI Express switch, providing a nominal bandwidth of 16 GB/s (single direction) between the system controller slot and PCI Express switch 2. PXI Express peripheral slots 11-18 are connected to PCI Express switch 2 with Gen-3 x8 PCI Express links and are downstream of system slot link 2.

The PCI Express-to-PCI bridge is connected to PCI Express switch 1 and provides a 32-bit, 33 MHz PCI bus for hybrid peripheral slots 7, 8, 9, 11, and 12.

The system controller slot also has connectivity to some PXI features such as: PXI_CLK10, PXI Star, PXI Trigger Bus, and PXI Local Bus 6. By default, the system controller controls the power supply with the PS_ON# signals. A logic low on this line powers on the power supply.

Note The chassis Inhibit Mode must be set to Default mode for the system controller to control the power supply. Refer to the Inhibit Mode section for details about configuring Inhibit Mode.