- a summary, overview or tutorial about PXI Express, the instrumentation
derivative of the PCI Express standard. PXI Express is used in a wide
variety of applications including test instrumentation, data acquisition and
many other areas where test data needs to be captured.
The PXI standard has become widely used in the years
since 1998 when it was launched. It has found many applications in fields
varying from automatic test to data acquisition. In these fields it has
become a very cost efficient and technically effective solution. One of the
key elements in this widespread level of acceptance has been the fact that
PXI uses the PCI standard in the communication backplane.
With computers as well as the data acquisition and test
automatic applications requiring greater levels of data transfer, higher
speeds and additional facilities, PXI has evolved to PXI Express, mirroring
the change from PCI to PCI Express.
Using PXI Express, users benefit from significantly
increased bandwidth, backward compatibility with existing PXI systems, and
additional timing and synchronization features. In this way additional speed
and flexibility were added, ensuring the PXI was able to meet the growing
needs of the data acquisition and test automation industries.
The signalling performance of PXI Express sees an
increase in the backplane capability raising the data transfer speed from
132 Mbps right up to 6 Gbps. By using this significant increase in
performance, PXI Express opens up many new applications for high performance
instrumentation and data acquisition applications. At the same time the new
specification retains backwards compatibility with the older PXI system
allowing systems to progressively migrate from one standard to the next.
PXI Express development
The development of PXI Express was fuelled by the
development of the PCI Express specification. This was first released in
2002 and it took until 2004 until PCI Express slots started to appear in
mainstream PCs. Many companies including Intel, Dell, Microsoft and HP
started to drive the technology.
PXI had established itself well in the industry for
applications including from test, control and data acquisition. PXI
technology had established itself to the extent that even during downturns
in the industry as a whole, the PXI adoption continued to gain momentum
against the industry trend. In 2004 PXI achieved a growth of over 40%.
Work started on PXI Express in may 2005 when the PXI
Systems Alliance (PXISA) began work on the PXI Express specification. They
worked with the PCI Industrial Manufacturers Group (PICMG) to ensure the PCI
Express technology was correctly integrated into the PXI Express backplane
while still preserving compatibility with the large installed base of PXI
existing systems. They had a deadline for completion of late 2005 for the
completion of the first release of the document.
