PCI eXtensions for Instrumentation

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PCI eXtensions for Instrumentation , PXI for short , is a bus system based on the PCI bus and a further development of the cPCI standard for measurement and automation technology. This means that no cables or signal conversions are required between the computer and the measuring device. Particularly fast processing can thus be carried out on the same card or on a neighboring card. PXI offers the highest bandwidth in the industry and the bus with the lowest latency .

Overview of the development from the PCI bus to the PXI Express bus

History and development

The PXI industry standard was developed by National Instruments in 1997 and has been on the market as an open industry standard since 1998 . This is managed by the PXI System Alliance. The PXI bus is based on the PCI bus, but has additional timing and trigger functions with a 10 MHz reference clock. This allows a very small difference in transit time of less than a nanosecond. There is also a connection to the backplane via seven-row, vibration-proof, moisture- and gas-tight and shielded plugs.

PXI backplane from ADLINK XBP-3006L

PXI is suitable as a platform for modular systems that require flexible software, low latency and high data throughput, as well as stand-alone systems. The PXI system can either be controlled with an embedded controller or with a separately connected computer.

advantages

  • Open, manufacturer-neutral standard
  • flexible software
  • modular
  • PCI bus with the following extras:
    • additional timing and trigger functions
    • 32 and 64 bit bus width at 33 MHz or 66 MHz
    • Clock 10 MHz
    • Trigger bus with 8 channels with a delay time difference of less than 1 nanosecond
    • durable & robust
    • well suited for industrial environment
  • Master-slave principle
  • compact
  • high data throughput and low latency

You only have to invest in components that are required for the respective application.

PXI chassis with embedded controller

PXI system

A PXI system essentially consists of three components.

PXI system with an embedded controller
  1. A stable, robust housing
    • PXI case
    • PXI Express chassis
    • Hybrid housing (PXI and PXI-Express compatible)
  2. A system controller
    • Embedded controller
    • Remote controller
  3. One / several peripheral module / s
    • Measuring device
    • Switch modules
    • PowerSupplys
    • ...

PXI System Alliance

The PXI System Alliance is an association of 69 members who manufacture or sell products based on PXI technology. Your goal is to maintain this bus standard, to develop it further and to increase the level of awareness so that as many as possible can benefit from the advantages. The open, manufacturer-neutral standard stipulates, for example, that the system card (controller interface to the PC) must, by definition, always be on the left edge, that a chassis must not have more than 31 slots, as well as other fixed framework conditions.

Members of the PXI Alliance include:

  • ADLINK
  • Applicos bv
  • CHROMA ATE
  • Digalog Systems Inc
  • Keysight Technologies
  • Marvin Test Solutions, Inc.
  • Pickering
  • StanTronic Instruments GmbH
  • Tabor Electronics Ltd.
  • ....

PXI Express

Schematic functionality of the PXI / PXI Express bus

PXI Express is the implementation of PCI Express technology in the existing PXI standard. The advantages of both systems are combined. Despite the very similar sounding names, the bus system is fundamentally different. Compared to the PXI bus, PXI Express does not have a split parallel bus system, but a separate serial point-to-point connection. This means that every PXI Express card has a dedicated bandwidth and a 45-fold increase in throughput compared to PXI. An additional clock of 100 MHz can also be used.

compatibility

The PXI standard is designed in such a way that cPCI cards can also be used in a PXI chassis and PXI cards also work in a cPCI chassis, albeit with limited functionality. Due to the development of the PCI Express standard, this compatibility is not always guaranteed because the two plug connections are not mechanically compatible. As a result, there are several connectors on the market. The original PXI-1 slot, PXI Express slot, PXI Express system slot and the PXI Express hybrid slot can now be found in housings. PXI Express peripheral modules, 32-bit CompactPCI modules and hybrid slot-compatible PXI modules can be used in a PXI Express hybrid slot. Only the original PXI-1 peripheral modules cannot be used. With some effort, however, these can be converted to hybrid slot-compatible PXI modules by removing the J2 connector and replacing it with an xJ4 connector, which is possible because not all pins are connected on the J2 connector.

market

In 2011, the market volume of PXI-based systems with over 1500 modules was almost 400 million US dollars and is currently the fastest growing market in the field of measurement and automation technology with a growth rate of 18.1%.

See also

Web links

Individual evidence

  1. ↑ a b Blank, H.-J. (1998). PCI in industry. 85540 Haar near Munich: MarktTechnik Buch- und Software-Verlag GmbH.
  2. ^ PXI System Alliance. (July 14, 2015). http://www.pxisa.org . Retrieved July 14, 2015 from http://www.pxisa.org : http://www.pxisa.org/userfiles/files/Specifications/PXIHWSPEC22.pdf
  3. ^ PXI System Alliance. (July 14, 2015). http://www.pxisa.org . Retrieved on July 14, 2015 from http://www.pxisa.org : Archived copy ( Memento of the original from December 19, 2015 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.pxisa.org
  4. ^ PXI Systems Alliance. (July 14, 2015). http://www.pxisa.org . Retrieved July 14, 2015 from http://www.pxisa.org : http://www.pxisa.org/About/MarketAcceptance.aspx