ta acquisition and instrumentation. Several instrumentation companies have joined the alliance and developed PXI products.As of August 2000, the PXISA voted to accept ownership of the specification, and to adopt a new revision, Rev. 2.0. Further revisions to the specification are anticipated over the next few years as the PXI Systems Alliance addresses other inherent design issues.Committees have now been established to deal with the issues of:1.Heating and Cooling (VXI has a comprehensive standard, PXI merely states adequate cooling must be provided.)2.IPMI and system management (software)3.Configuration and control of PXI resources (software)4.Creating a 6U standard (a move highly supported by Racal in order to create a more meaningful instrument platform)StandardsVXI has the volume required to remain viable for years to come. As an evolving new technology, PXI is dependent on the Compact PCI volume to develop economies of scale. Compact PCI is currently popular with telecommunications systems manufacturers.Bus standards in the PC and Telecommunications world evolve much more quickly than in the test and measurement world. It remains to be seen whether PXI will develop the volumes required to remain a stable long-term standard as the PC and Telco worlds move on and evolve.Modules vs. CardsVXI modules have an outer metal enclosure to minimise cross-talk from slot to slot. These enclosures are connected to the chassis ground and act as a shield to prevent noise from coupling from one instrument to the next. PXI modules are cards and do not include any shielding. For high performance applications, it could become necessary for the PXI system user or integrator to experimentally identify and eliminate inter-card noise issues.Use of modules facilitates rapid removal and replacement of instruments. High-performance and high-density VXI instruments often contain multiple PCB’s in a single module. These boards and circuits are neatly co...
