Powering Up The Mxi-Express System; Powering Down The Mxi-Express System; Checking Leds For Status - National Instruments PXI Express PXIe-1073 User Manual

Powering Up the MXI-Express System

1. Power on the chassis.
2. Power on the host.
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.
The PXIe-1073 chassis will assert a wake signal on power up. The host PC
Note
also will power on if it supports this functionality.

Powering Down the MXI-Express System

Because operating systems and drivers commonly make the assumption that PCI Express/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. As a result, the user must press and
hold the power button for 3 seconds in order to power down a linked-up PXIe-1073. The order
in which expansion chassis are powered off, relative to each other, is not important.
If the PXIe-1073 experiences a fan or power supply failure, the chassis will
Note
power down and remain in standby indefinitely until AC power has been cycled. This
failure could cause the upstream system to crash or hang.

Checking LEDs for Status

After powering on the PXIe-1073 chassis you should check the LEDs for status to ensure that
all connected systems have linked. The following table defines the LED states.
LED
PWR
LINK
Table 2-1. LED Status for the PXIe-1073 Chassis
Color
Off
Green
Red
Blinking Red
Off
Green
Meaning
No power
Power is within spec
Fan failure
Power is out of spec
Link not established
Link established
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PXIe-1073 User Manual