Chapter 3
Hardware Overview
©
National Instruments Corporation
3-3
MXI-Express x16 for PXI Express Series User Manual
Cabled MXI-Express x16 Connector
The cabled MXI-Express x16 connector provides the transmit and receive
signals to connect an NI PCIe-8388 and an NI PXIe-8388/9, plus some
miscellaneous signals such as a clock and reset.
PCI Express-to-PCI Bridge
The
PCI Express Base Specification
defines a PCI Express-to-PCI bridge
as a device that connects a PCI Express fabric and a PCI hierarchy. On the
NI PXIe-8388/9, the PCI Express-to-PCI bridge connects the PCI Express
switch and an SMBus Master on the board.
SMBus Master
The SMBus is a low-speed bus for reading and configuring devices outside
the normal PCI Express mechanism. The PXI Express specification
requires controllers to supply an SMBus for reading chassis configuration
information from an EPROM. You also can use it for fan control, power
monitors, or other system devices. In addition, devices on plug-in boards
may connect to the SMBus for purposes specific to those devices.
LED Indicators
The LEDs on MXI-Express x16 cards give status information about power
supplies and link state. The NI PXIe-8388 has one tri-color LED for the
port on the panel. The NI PXIe-8389 has two tri-color LEDs, one for each
port.
Table 3-1 describes the NI PXIe-8388/9 front-panel LEDs.
The NI PXIe-8388/9 has additional LEDs on the back of the board near the
front panel connector. These LEDs give additional information about the
link status of the PCI Express lanes on the module to the backplane.
Table 3-1.
NI PXIe-8388/9 Status LED Messages
LED
Meaning
Off
Power is off
Red, blinking
Power is out of spec
Amber
Power is within spec; link not established
Green
Power is within spec; link established
