Chapter 2
Installation and Configuration
©
National Instruments
2-9
MXI-Express Gen II x8 Series User Manual
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 turned on before the host PC for
the BIOS and OS to correctly configure a MXI-Express Gen II x8 system.
Powering Off the MXI-Express Gen II x8 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 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. However, once the host PC
is powered off, the order that the expansion chassis are powered off is not
important.
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. However, this behavior cannot be
guaranteed.
LED Indicators
The LEDs on MXI-Express Gen II x8 cards give status information about
power supplies and link state. The NI PCIe-8381, NI PXIe-8381 and
NI PXIe-8384 have one tri-color LED on the panel, indicating power and
link status.
Table 2-3.
LED Status Descriptions of MXI-Express Gen II x8 Products
Board
LED
Color
Meaning
PWR/LINK
Off
Power is off
Blinking Red
Power is out of spec
Solid Amber
Power is within spec;
no link to chassis
Solid Green
Power is within spec;
link established
