PXI Express Tutorial

- 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.