National Instruments MXI-Express Gen-3 x16 User manual

USER MANUAL
MXI-Express Gen-3 x16
MXI-Express Gen-3 x16 Multisystem eXtension Interface for PCI
Express, CompactPCI Express, and PXI Express Bus Systems
This document provides installation, configuration, and reference information for MXI-
Express Gen-3 x16 controllers.
Caution This icon denotes a caution, which advises you of precautions to take to
avoid injury, loss of data, or a system crash.
Caution Using the MXI-Express Gen-3 x16 controllers in a manner not described
in this document may impair the protection the controllers provide.
Contents
Overview...................................................................................................................................2
Description and Features...........................................................................................................3
Functional Block Diagram........................................................................................................ 4
Basic MXI-Express Gen-3 x16 Systems...................................................................................6
Larger MXI-Express Gen-3 x16 Systems.................................................................................7
Connection Options...................................................................................................................8
Compatibility with Host PCs.................................................................................................. 10
Installation and Configuration.................................................................................................11
Equipment Needed.......................................................................................................... 11
Unpacking............................................................................................................................... 11
Hardware Installation..............................................................................................................12
Installing a PCIe-8398.................................................................................................... 12
Installing the Low-Profile Bracket on the PCIe-8398 (Optional)...................................13
Installing a PXIe-8398, PXIe-8399, or PXIe-8394.........................................................14
Cabling............................................................................................................................ 16
Powering On the MXI-Express Gen-3 x16 System........................................................ 17
Powering Off the MXI-Express Gen-3 x16 System....................................................... 17
LED Indicators........................................................................................................................18
PXI Express Onboard LEDs........................................................................................... 19
PCIe-8398 Onboard LEDs.............................................................................................. 21
Software Installation and Configuration................................................................................. 22

Specifications.......................................................................................................................... 23
PCIe-8398 (156877x-01L) Specifications...................................................................... 23
PXIe-8398 (156874x-01L) Specifications...................................................................... 26
PXIe-8399 (156874x-02L) Specifications...................................................................... 29
PXIe-8394 (156874x-04L) Specifications...................................................................... 32
Common Questions.................................................................................................................35
General Hardware........................................................................................................... 35
MXI-Express Gen-3 x16 Upgrade Questions................................................................. 36
General Software.............................................................................................................36
Documentation Notice for Third Party Software....................................................................37
Overview
Gen-3 MXI-Express is based on off-the-shelf PCI Express technologies. A Gen-3 MXI-
Express module can control PXI Express or CompactPCI Express chassis from a PC or a PXI
Express or CompactPCI Express chassis. The architecture is transparent to device drivers, so
no additional software is needed for PXI Express devices installed in connected chassis.
Note For full PXI/PXI Express functionality such as chassis and controller
identification, trigger routing, and slot detection, install the PXI Platform Services
software included with your kit. You also can find this software at ni.com/
updates by searching for PXI Platform Services.
The basic PCI Express lane consists of dual unidirectional differential links implemented as
one transmit pair and one receive pair. The link between the PC and chassis can be up to 16
lanes wide and supports speeds up to PCI Express Gen-3.
The following table lists the signaling rate of each PCI Express generation.
Table 1. PXI Express Generation Signaling Rates
PCI Express Generation Signaling Rate
First 2.5 Gb/s/lane/direction of raw bandwidth
Second 5.0 Gb/s/lane/direction of raw bandwidth
Third 8.0 Gb/s/lane/direction of raw bandwidth
Note This link is compatible with the cabled PCI Express specification developed
by the PCI-SIG.
2| ni.com | MXI-Express Gen-3 x16 User Manual

Description and Features
MXI-Express Gen-3 x16 extends PCI Express communication over a cable up to 3 m. With
MXI-Express Gen-3 x16, you can do the following:
• Control a PXI Express or CompactPCI Express backplane with a PCI Express-based PC.
• Physically separate the measurement or automation system from a host PC.
• Control multiple PXI Express or CompactPCI Express chassis with a single PCI Express-
based PC or PXI Express embedded controller. (The PXIe-8398 and PXIe-8399
controllers also can control multiple chassis in a daisy-chain configuration.)
The following table lists the models and their features for comparison.
Table 2. Feature Comparison of Available MXI-Express Gen-3 x16 Interfaces
Model Slot Type Number of Lanes Cable Support
PCIe-8398 PCI Express Gen-3 x16 16 MXI-Express x8
PXIe-8394 PXI Express Peripheral
Expansion Module
16 MXI-Express x8,
MXI-Express x4
PXIe-8398 PXI Express Controller 16 MXI-Express x8,
MXI-Express x4
PXIe-8399 PXI Express Controller
With One Expansion Slot
32 MXI-Express x8,
MXI-Express x4
Tip For optimum link widths and performance, use the PXIe-8394, PXIe-8398, and
PXIe-8399 in chassis that support Gen 3 links.
MXI-Express Gen-3 x16 User Manual | © National Instruments | 3

Functional Block Diagram
Figure 1. PCIe-8398 (156877x-01L) Block Diagram
MXI-Express
Gen-3 x16
PWR/LNK
Status LED
PCI Express Gen-3 x16
PCI Express Gen-3 x16
PCI Express
Switch
4| ni.com | MXI-Express Gen-3 x16 User Manual

Figure 2. PXIe-8398 (156874x-01L) and PXIe-8399 (156874x-02L) Block Diagram
MXI-Express
Gen-3 x16
PCI Express Gen-3 x16
PCI Express Gen-3 x4
PCI Express Gen-3 x4
PCI Express Gen-3 x4
PCI Express Gen-3 x4
PCI Express
to
PCI Bridge
SMBus
Master
PCI Express
Switch
Note The width and speed of the PXI Express backplane links are chassis
dependent.
The PXIe-8398 and PXIe-8399 work in both two and four-link chassis. A four-link chassis
supports four links up to x4 width each, for a maximum of 16 PCI Express lanes. A two-link
chassis supports one link up to x8 and a second link up to x16, for a maximum of 24 PCI
Express lanes. The PXIe-8398 and PXIe-8399 maximize the use of all available backplane
lanes for either configuration.
Note National Instruments offers Gen 3 PXI Express chassis that allow the
PXIe-8398 and PXIe-8399 to establish Gen 3 backplane links.
MXI-Express Gen-3 x16 User Manual | © National Instruments | 5

Figure 3. PXIe-8394 (156874x-04L) Block Diagram
PCI Express
Switch
PCI Express Gen-3 x16
PCI Express Gen-3 x8
MXI-Express
Gen-3 x16
Note The width and speed of the PXIe-8394 backplane links are chassis
dependent.
Note National Instruments offers Gen 3 PXI Express chassis that allow the
PXIe-8394 to establish Gen 3 backplane links. A chassis can support up to a x8 link.
Basic MXI-Express Gen-3 x16 Systems
The simplest MXI-Express Gen-3 x16 system consists of a PCIe-8398 in a PC connected to a
PXIe-8398 in the controller slot of a PXI Express chassis, as shown in the following figure.
Figure 4. Example of a Basic MXI-Express Gen-3 x16 Link Topology
Note In this manual, whenever a PXI Express chassis is referenced, you could use
a CompactPCI Express chassis instead.
6| ni.com | MXI-Express Gen-3 x16 User Manual

Larger MXI-Express Gen-3 x16 Systems
There are several ways to connect multiple chassis to a host system. Which you choose
depends on your design goals and requirements.
If you are using a PC to control the chassis, and if multiple x16 PCI Express slots are available
in the host PC, you can use multiple PCIe-8398 modules to connect to the PXIe-8398 in each
chassis ("star" topology). This method offers the most bandwidth and lowest latency to the
host for all the chassis.
Figure 5. Example of a Star MXI-Express Gen-3 x16 System Expansion Topology
If you are using a PC to control multiple chassis but do not have additional PCI Express slots
in the PC, you can use a PXIe-8399 to daisy-chain to an additional chassis ("daisy-chain"
topology). The PXIe-8399 supports two x16 links on its front panel, and you can connect the
second link to an additional chassis. For example, you could set up two chassis using a
PCIe-8398 in the host PC cabled to a PXIe-8399 in the first chassis. The PXIe-8399 in the first
chassis would also be cabled to a PXIe-8398 in the second chassis. If a third chassis is desired,
the second chassis could use another PXIe-8399.
MXI-Express Gen-3 x16 User Manual | © National Instruments | 7

Figure 6. Example of a Daisy-Chain MXI-Express Gen-3 x16 System Expansion
Topology
If you are using an embedded controller, you can use a PXIe-8394 to expand to additional
chassis. As with a PC host, you can use a PXIe-8394 card per additional chassis (preferred), or
you can daisy-chain additional chassis using the PXIe-8399. The PXIe-8394 backplane
connection is limited to Gen 3 x8.
Figure 7. Example of a MXI-Express Gen-3 x16 System Expansion Topology Using a
PXIe-8394 in Each Chassis
Systems need not be exclusively star or daisy-chain. It is generally preferable to use a star
topology, but you can daisy-chain or star additional chassis as needed. There are additional
choices, described in the next section, if the full x16 bandwidth is not required.
Connection Options
The MXI-Express Gen-3 x16 connectors are modular and can be cabled in several
configurations. The hardware makes the configurations without user intervention. The
8| ni.com | MXI-Express Gen-3 x16 User Manual

configuration mechanism requires PCI Express cables, not the connector-compatible cables
that other standards use. When multiple cables are used for a single link, the cables must be
the same length.
Note National Instruments offers x8 cables. x16 connections require two cables,
and the cables must connect the ports in ascending order. For example, ports 1-2 of a
PCIe-8398 will connect to ports 1-2 of a PXIe-8398, and ports 3-4 will connect to
3-4.
For the PXIe-8399, connect daisy-chain ports 5 and 6 to ports 1 and 2 on the PXIe-8398 or
PXIe-8399.
Figure 8. Connection Options
PXIe-8399 PXIe-8398 PXIe-8394
PCIe-8398
PXIe-8399 PXIe-8398 PXIe-8394
PWR/
LINK
PWR/
LINK
PWR/
LINK
PWR/
LINK
4
1
4
3
2
1
4
3
2
1
4
3
2
1
8
7
6
5
PWR/
LINK
MXI-Express MXI-Express MXI-Express
Port 1 of the PXIe-8398 and PXIe-8399 is upstream facing, meaning it is the link going toward
the host. This means it is connected to a PXIe-8394, PCIe-8398, or a downstream facing port
of a PXIe-8398 or PXIe-8399.
MXI-Express Gen-3 x16 User Manual | © National Instruments | 9

Ports 1-4 ordinarily are cabled to the host PC or the chassis containing the embedded
controller. In this configuration, ports 1-4 form a x16 link, offering the highest throughput.
Ports 5-8 of a PXIe-8399 and ports 1-4 of a PXIe-8394 and PCIe-8398 are always downstream
facing, meaning they may be connected only to additional chassis that are farther from the
host. They ordinarily are connected to a single PXIe-8398 or PXIe-8399.
Ports 2, 3, and 4 of the PXIe-8398 and PXIe-8399 are upstream facing by default, but they
change direction based on cabling. While they are normally used (along with port 1) to form a
x16 upstream link, they may alternatively be connected to additional chassis, and they become
downstream facing ports. There can be only one upstream facing link per chassis, but it may
comprise one, two, or four ports to form a x4, x8, or x16 link.
The following table lists possible configurations.
Module Configuration 1 Configuration 2 Configuration 3 Configuration 4
PCIe-8398 1-4: x16 1-2: x8
3-4: x8
— —
PXIe-8394,
PXIe-8398,
PXIe-8399
ports 1-4
1-4: x16 1-2: x8
3-4: x8
1-2: x8
3: x4
4: x4
1: x4
2: x4
3: x4
4: x4
PXIe-8399
ports 5-8
5-8: x16 5-6: x8
7-8: x8
5-6: x8
7: x4
8: x4
5: x4
6: x4
7: x4
8: x4
The flexible port configurations allow you to prioritize bandwidth (Configuration 1), high
fanout (Configuration 4), or a blend of the two.
Compatibility with Host PCs
The BIOS of some host computers may have limited support or no support for extending the
PCI Express fabric. These systems may fail to boot or fail to function correctly.
For more information about host system compatibility with MXI-Express Gen-3 x16 products,
refer to the NI Developer Zone document Tips to Help You Successfully Use NI MXI-Express
Controllers at ni.com.
10 | ni.com | MXI-Express Gen-3 x16 User Manual