Connect the MXI-Express x8 cables to both MXI-Express Gen-3 x16 modules. The cables
have no polarity, so either end may be connected to either card.
Note
Two x8 cables plugged into the MXI-Express Gen-3 x16 modules make the
x16 link.
Caution
Do not remove the cable after the system is powered on. Doing so can
hang or cause errors in applications communicating with devices behind MXI-
Express Gen-3 x16. If a cable becomes unplugged, plug it back into the system. You
will need to restart your computer.
Powering On the MXI-Express Gen-3 x16 System
1.
Power on all the expansion chassis in any order you choose.
The PXIe-8398 has a built-in feature that powers on/off the chassis it is controlling when
the host system is powered on/off. You can override this feature by manually powering on
the downstream chassis through chassis-specific means.
2.
Power on the host.
Note
There are no requirements for how expansion chassis are powered up relative
to each other, as long as they are all on before the computer is powered on.
Observe the LED status on the PCIe-8398, PXIe-8399, PXIe-8398, and PXIe-8394 where
applicable. A properly connected and powered up system should report a valid link and power
status on all of these boards once the host PC is powered on. Refer to the
LED Indicators
section for more information.
Typical PCI Express switches are used to add PCI devices to a PCI hierarchy in which all the
bridges and devices are contained within a single chassis. Because of this, BIOSes and
operating systems make the assumption that all PCI devices in the entire hierarchy will be
available as soon as code execution begins at power-up time. This assumption means that all
of the expansion chassis must be powered on before the host PC for the BIOS and OS to
correctly configure a MXI-Express Gen-3 x16 system.
Powering Off the MXI-Express Gen-3 x16 System
Once the host PC is powered off, the expansion chassis will power down automatically.
Because operating systems and drivers commonly make the assumption that PCI devices will
be present in the system from power-up to power-down, it is important to not power off the
expansion chassis until after the host PC is powered off. Powering off the expansion chassis
while the host is still on can cause crashes or hangs.
Note
To power off the chassis while the host computer or host chassis is on, you
may need to hold the power button for at least four seconds.
MXI-Express Gen-3 x16 User Manual
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© National Instruments
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