© National Instruments
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MXI-Express x1 Series User Manual
3.
Observe the LED status on the NI PCI-8361, NI PCIe-8361/8362, NI PXI-8360/8364/
8367/8368, and NI PXIe-8360/8364/8367/8368 where applicable. A properly connected
and powered up system should display a valid link and power status on
all
of these boards
once the host PC is powered on. Refer to the
section for more information.
Typical PCI-PCI bridges 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 turned on before the host PC for the BIOS and OS to correctly configure a MXI-Express
system.
Note
In some cases where there is an invalid MXI-Express x1 connection, some
boards may report a valid link while others do not. It is important to observe a valid
link status across
all
connected MXI-Express x1 boards when the host is powered on
to ensure a valid configuration.
Powering Off the MXI-Express x1 System
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 not to 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. However, once the host PC is powered off,
the order that the expansion chassis are powered off is not important.
LED Indicators
The LEDs on MXI-Express x1 cards provide status information about power supplies and link
state. The NI PCI-8361, NI PXI-8364/8367, and NI PXIe-8364 all have one tri-color LED on the
panel, indicating power and link status. The NI PCIe-8362 has two tri-color LEDs on the panel,
indicating power and link status for each port. The NI PXI-8360/8368 and NI PXIe-8360 have
two LEDs, one for power supply status and one for link state.
Note
In some cases where there is an invalid MXI-Express x1 connection, some
boards may report a valid link while others do not. It is important to observe a valid
link status across
all
connected MXI-Express x1 boards when the host is powered on
to ensure a valid configuration.