Achieving Robust Interchangeability of Test Assets in ATE Systems
What are the Measurement and Stimulus Subsystems (MSS) and what do they have to do with IVI?
The measurement subsystems architecture (MSA), developed by Agilent Technologies, serves as a key part of the design of several recently-introduced Agilent Technologies test products (e.g., the Agilent Technologies phase noise system). This architecture incorporates the concept of asset control modules, which permit easy instrument interchangeability. Based on this design approach, a test system can provide the same answer after obsolete instruments are replaced by newer products.
IVI class drivers, when approved, can provide syntactical interchangeability (the ability to run an application program without program errors after interchanging an instrument). This is an important step in making useful measurements after substituting an instrument. However, using IVI class drivers alone cannot guarantee that same measurement results will be observed. Because of this, many of the IVI Foundation members were interested in the additional interchangeability protection that can be achieved using MSA in addition to IVI drivers. As a result, an IVI subgroup has been formed to sponsor on-going development. This work is now being referred to in the IVI Foundation as IVI-MSS for IVI Measurement and Stimulus Subsystems.
IVI-MSS based solutions also provide the ability to use instruments of an entirely different class. For instance, the phase noise system mentioned above, can use either a spectrum analyzer or a fast A/D converter for one of its measurements. This sort of interchangeability is beyond the scope of IVI class drivers.
Key Principles of MSS:
- Measurements have value independent of instruments and applications.
- A measurement's utilization of instrument features is tightly controlled.
- A subsystem provider can guarantee a support life beyond the life of utilized instruments.
- Knowing who owns various interfaces is crucial.
To provide truly robust interchangeability, measurement differences such as input impedance and autoranging algorithms occasionally need to be taken into account. This is another reason that solutions beyond the driver need to be considered.
Agilent Technologies plans to provide measurements to customers that can be supported for up to 20 years, make sure these measurements easily integrate into customers systems, and work with the IVI-MSS subgroup to provide an open standard to the industry so that customers can easily integrate multi-vendor solutions.
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Want more details?
See the Technical Note: Applying New Software Technologies To Solve Key System Integration Issues, by Roger Oblad of Agilent Technologies, http://www.ivifoundation.org/groups/MSS/PublicDepot/Autotestcon-1997-Paper.pdf delivered at the 1998 AUTOTESTCON Conference.
Also refer to the keynote speech, Connecting You To The Future, delivered by Ned Barnholt, VP & GM of the Agilent Technologies Test & Measurement Organization, at the 1998 AUTOTESTCON conference. Note: Please enter the title in "Quick Search" to locate the text of the speech.
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Achieving Robust Interchangeability of Test Assets In ATE Systems
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