LAN eXtensions for Instrumentation

LAN eXtensions for Instrumentation, LXI short, is an open specification to network measurement instruments and systems via Ethernet (LAN) with each other. The LXI organization currently consists of approximately 50 manufacturer of measuring instruments. With the widespread LAN technology easily be large and spatially distributed test and measurement systems networked together. Also, access to a corporate network on the entire test system is possible.

Every LXI instrument includes in addition to the required LAN interface a special web interface with server and browser which provides the actual functionality.

Classes

Large and complex measurement and inspection processes make a synchronization of the measuring instruments involved required so that, for example, a signal power will only be measured when the signal is really present. Measuring devices for such applications have a so-called trigger input, through which a start signal is supplied. Receives the meter of this signal, it begins with the measurements previously set.

Through communication via the Ethernet triggerings are possible only under special conditions. For this reason, the three classes were originally defined that describe the requirements for the precision of the timing of a device.

Class C

About the LAN only, the measurement and control data to be transferred. Triggering occurs on the meter via independent inputs and outputs.

Class B

For Class B equipment, the synchronization of the measuring instruments via the IEEE 1588 Precision Time Protocol (PTP ) is carried out. This standard allows the synchronization of the whole, associated with LXI measurement system. The individual clocks may thereby have different resolutions, accuracies and stabilities. By synchronizing with IEEE 1588 PTP time accuracy in the nanosecond range can be achieved.

Class A

In class A, the IEEE 1588 PTP synchronization is extended to the Wired Trigger Bus ( WTB ). This is very time- critical measurement setups feasible, provided that they are spatially compact.

Version level LXI 1.4

In this versioning the "3- class system " was dissolved. From the entry level C standard was based. The hitherto in classes B and A additively additional requirements have been split into individual requirements that can be achieved individually. The hitherto always geisternde by the press, never adopted class C (to account corresponding to class C, as well as realization of the trigger bus, which is called in Class A, but without the requirements of Class B ) is possible.

Revision history

  • Establishment of the LXI consortium in September 2004
  • LXI 1.0, released in September 2005
  • Certification of the first LXI-compliant instruments in December 2005
  • LXI 1.1, published in August 2006
  • LXI 1.2, published in October 2007
  • LXI 1.2.01, released in November 2007
  • LXI 1.3, published in October 2008
  • LXI 1.4, published in May 2011
  • LXI 2.0, in preparation
Webbrowser PCI eXtensions for Instrumentation
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