In today's rapidly evolving technological landscape, transitioning from VXI (VME eXtensions for Instrumentation) to PXI (PCI eXtensions for Instrumentation) has become increasingly important for companies striving to maintain operational efficiency and market competitiveness. With the VXIbus consortium no longer active and new VXI products dwindling, the availability and future stability of your test systems lie in the transition to PXI.
This article explores two real-world scenarios in which an international aerospace company performed a VXI to PXI migration. These examples provide practical insights into overcoming challenges, achieving project goals, the technical considerations inherent in migrating from VXI to PXI systems, and the innovative solutions available to facilitate this transition.
Why Migrate to PXI? Before we jump into the details of the migration projects, it’s worth reflecting on why PXI has become the de facto modular platform for the migration of obsolete VXI test systems.
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Figure 1 - Shows VXI switching on the left and PXI switching on the right.
Key Benefits of PXI:
- Availability: PXI has become the dominant global industry standard for functional test, ATE, data acquisition and process automation applications. Thousands of PXI modules are available, including DC to microwave source & measure instrumentation, data acquisition, switching, digital I/O, communications modules, etc. Contrast this to VXI, for which most vendors have now obsoleted their product offerings.
- Improved Performance: Higher bandwidth, faster data acquisition rates, and greater processing power result in more efficient test cycles.
- Future-proofing: The PXI platform benefits from a large ecosystem of vendors and thousands of global users. It is actively governed by the PXI Systems Alliance, an industry body with over 50 member companies, which ensures the standard’s relevance and longevity.
- Reduced Footprint: PXI systems typically offer higher channel density in a smaller hardware form factor, saving valuable test lab space.
- Transition Tools: Pickering offers a free suite of tools to assist in your migration plan, including a hardware simulation tool to allow software migration/testing before your hardware is in place, a cable design tool that provides a graphical, customized approach for your connectivity goals and a VXI-PXI product selector to assist in making informed decisions on replacement modules.
Challenges to Anticipate:
- Compatibility Considerations: Reusing legacy equipment, especially ITAs (Interface Test Adapters), connections and signal routing solutions, can be challenging. The tables in this article, "VXI and PXI Platforms in Switching Applications: How to Migrate and Cross-Reference," map out potential Pickering PXI replacements for VXI switching modules from several vendors.
- Software Migration/Regeneration: Existing application software will need to be translated to the new platform or regenerated from scratch, which can be a major undertaking, especially if multiple DUTs are tested on the same system.
- Qualification and Validation: Migrating to PXI often requires rigorous H/W and S/W validation to ensure compliance with industry standards.
- Learning Curve: Teams transitioning to PXI need time to onboard and train on the new systems, especially if recent hires dominate workforce demographics. At the heart of our migration strategy is collaboration. Our team of seasoned professionals has years of experience in both VXI and PXI systems and has successfully navigated numerous migration projects. This collaborative approach not only maximizes the use of existing systems, but also seamlessly integrates new solutions.
Considering these points, here’s how two independent migration projects tackled these challenges to achieve positive outcomes.
Application 1: Migrating Guidance System Testing
The Context
An international aerospace company faced the challenge of modernizing its testing infrastructure for inertial guidance systems used in critical defense applications. The customer’s legacy VXI-based systems were essential to supporting production and operational verification. However, delays in implementing the new system required extending the life of these test systems for at least 20 additional years.
The project consisted of eight test systems, six of which were essential production units. The primary goal was to replace legacy VXI switching modules with functionally equivalent PXI technology, while maintaining signal integrity and operational compatibility with existing systems.
Our Approach
- Hardware Replacement: Examples of the legacy VXI switching modules replaced by Pickering PXI cards are:
o ASCOR 3000-39A RF SPDT replaced by Pickering 40-754A module (PXI RF Switch, 9xSPDT, 500 MHz, 50 Ω, Multiway Connectors)
o ASCOR 3000-08 Multiplexer replaced by Pickering 40-610A modules (PXI High-Density Multiplexer, 8-Bank, 16-Channel, 1-Pole)
The PXI modules were housed in one of our Hybrid PXIe chassis, together with NI DAQ hardware. Our signal routing software, Switch Path Manager, enabled efficient signal routing and reuse of existing configuration files, dramatically simplifying the software migration process.
- Integration of Legacy ITA Connections: Our standard and custom cabling solutions enabled the reuse of existing interface hardware (e.g., the original VPC 9025 mass-interconnect receiver) to minimize rework.
- Team Training: With a predominantly new workforce, hands-on training with PXI instrumentation and LabVIEW programming ensured the success of future system operations.
The Outcome
This streamlined approach provided a flexible, high-performance testing system while resolving scalability challenges. The modernized PXI platform offered measurable gains in speed and accuracy, meeting the end customer’s objectives without significant disruption to production schedules.
Application 2: Overhauling Gyroscope Test Stations
The Context
A second migration project aimed to modernize test stations used for gyroscope performance verification. These stations were vital for monitoring inertial sensors subjected to extensive mechanical inversion cycles—an operation critical to precision aerospace applications.
The legacy system relied on an obsolete HP VXI chassis, Racal multiplexer, and custom switching cards to support input/output signal handling for multiple gyroscopes under test. The overarching goal was to extend the system’s life cycle by 15–20 years while improving reliability and ensuring active vendor support and access to spares.
Our Approach
- Hardware Upgrades: Three Racal MUX modules and custom VXI switching modules were replaced with our 40-670C and 40-610A PXI signal multiplexing cards. The updated configuration utilized NI PXIe-1095 chassis paired with high-performance embedded controllers.
- Simplified Signal Management: PXI cards separated previously integrated MUX and signal processing functions onto dedicated modules, improving maintainability and performance.
- Software Migration: The legacy ADA programming environment was replaced with LabVIEW RT, streamlining the software integration process and ensuring compatibility with modern tool chains.
The Outcome
The PXI-based architecture enabled enhanced test reliability, reduced signal interference, and faster cycle times. Leveraging modular PXI cards also boosted system fault tolerance, allowing the replacement of individual components without significant downtime.
Lessons Learned
Both projects highlight several key takeaways for organizations considering migrating from VXI to PXI platforms.
- Plan for Compatibility – Reusing legacy equipment, such as ITA connections or power distribution networks, can reduce project costs and minimize operational disruptions.
- Prioritize Training – A skilled team is critical to the successful implementation and maintenance of PXI platforms. Training on new software tools like Switch Path Manager or LabVIEW can accelerate adoption.
- Partner with Experts – Collaborating with solution-oriented vendors ensures you have access to tailored hardware, software, and support for complex migration projects. We have pioneered several innovative methods to facilitate these transitions. For instance, a 2-slot LXI chassis integrated with a switch module was employed in one application, and a VXI-PXI carrier was used in another to qualify PXI within an existing VXI setup.
- Think Long-Term – Migration efforts should prioritize scalability and system longevity to maximize returns on investment.
Learn More About VXI to PXI Switching Applications :
The shift from VXI to PXI isn’t merely a trend—it’s a necessity. While the transition from VXI to PXI requires careful planning and execution, the benefits of moving to a more robust and supported platform are significant. By leveraging our tools, expertise, and collaborative spirit, your transition can be efficient and effective, paving the way for sustained technological evolution and success.
If your organization faces similar challenges with legacy test systems, now is the time to evaluate your options. Migrating to PXI offers clear performance benefits, streamlined operation, and a future-proof platform you can rely on for decades to come.
What challenges have you experienced in modernizing your test systems? We’d love to hear your experiences—connect with our experts.
Learn More About VXI to PXI Switching Applications
