MXI-Express x4 is based on PCI Express technology. A MXI-Express x4 kit uses PCI Express switches to enable control of a PXI Express or CompactPCI Express chassis from a PC with an available PCI Express slot, or from a PXI Express chassis with an available PXI Express slot. The switch architecture is transparent to device drivers, so no additional software is needed for CompactPCI Express level support for PXI Express devices in connected chassis.
The link between the PC and the chassis is a x4 cabled PCI Express link. This link is a dual-simplex communication channel comprised of four low-voltage, differentially driven signal pairs. The link can transmit at a rate of 10 Gbps in each direction simultaneously.
The BIOS of some host machines may not support the extension of the PCI Express fabric or PCI bus. Because this is the primary function of MXI-Express x4 products, those systems may not boot or function correctly. To address this issue, certain MXI-Express x4 products have additional functionality intended to hide all PCI or PCI Express resources connected to the host machine, and allow NI MXI-Express BIOS Compatibility Software to handle the enumeration process of these resources instead of the BIOS.
In the cases where this software is required, you may need to toggle a dip switch on the board as described in the software documentation. Only the first dip switch is for this purpose. The other switches serve no function; leave them in their default position.
Unless NI MXI-Express BIOS Compatibility Software is installed on the host machine for use, the BIOS Compat Mode dip switch (switch 1) should remain in the off position. If this mode is enabled on a MXI-Express x4 product in a host machine that does not have the software installed, the operating system does not detect the connected devices.
For more information about host system compatibility with MXI-Express x4 products, refer to the Tips to Help You Successfully Use MXI-Express Controllers document at ni.com.