Keysight M9021A, Installation Manual

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28 Keysight PXIe System and Cable Interface Installation Guide
M9022A, M9023A, M9024A System Module Installation
Transfer Rate Settings
Link settings determine the fastest transfer rate at which the module will support
PCIe. The default switch setting allows the PCIe links to train to a maximum of
Gen3. The module will train its link to a slower speed if the other end of the link
cannot support Gen3.
Some devices are old or low performance and can not support Gen3 speeds.
Sometimes a device also cannot correctly follow the PCIe training protocol and
the link fails to connect reliably. As a workaround or diagnostics debug step, you
can throw the switches on the M9022A, M9023A, and M9024A modules to lower
the maximum speed to Gen 1. This lower speed may allow the device to function
reliably. For these devices, the Gen1 speed is usually not a throughput
performance bottleneck.
Using the M9024A on an M9018 with 4x4 PCIe Switch Fabric
M9024A can be used in an M9018 or M9019A PXIe Chassis. The M9018 can be
configured using the PCIe Switch Fabric Configurator to set the PXIe Chassis
switch fabric to one of 1x8, 2x8, or 4x4. The 2x8 configuration is the default
configuration for the M9022A, M9023A, and M9024A modules. However, if you
set the M9018 to a switch fabric of 4x4, and you are using the M9024A, you will
need to make a switch setting change on the M9024A so that the IO ports will
operate properly.