©
National Instruments Corporation
3-1
MXI-Express x16 for PXI Express Series User Manual
3
Hardware Overview
This chapter presents an overview of MXI-Express x16 hardware
functionality and explains the operation of each functional unit.
Functional Overview
MXI-Express x16 is based on PCI Express technology.
A MXI-Express x16 kit uses PCI Express switches to enable control of a
PXI Express or CompactPCI Express chassis from a PC with an available
PCI Express slot. The PCI Express switch architecture is transparent to
device drivers, so no additional software is needed to support using
PXI Express and CompactPCI Express devices in a chassis connected
using MXI-Express x16.
Note
The PXI Platform Services software on the
PXI Platform Services
CD or driver CD
included with your PXI Express MXI-Express x16 hardware is required to provide chassis
and controller identification for PXI features such as trigger routing and slot detection. The
PXI Platform Services software also is included with the NI-DAQmx and NI-VISA drivers.
For more information, refer to KnowledgeBase 3TJDOND8 at
ni.com
.
The link between the PC and the chassis is a x16 PCI Express link. This link
is a dual-simplex communication channel comprised of low-voltage,
differentially driven signal pairs. The link can transmit at a rate of
8 Gbytes/s in each direction simultaneously, though protocol overhead and
other inefficiencies reduce the achievable throughput.
Figure 3-1 shows the basic architecture of MXI-Express x16. The
NI PCIe-8388 consists of a PCI Express x16 board edge connector,
PCI Express repeaters, and one cabled MXI-Express x16 connector. The
NI PXIe-8388/9 consists of one or two cabled MXI-Express x16
connectors, a PCI Express switch, and PXI Express connectors.
