PXI joined by VXI and AXIe at Autotestcon USA
Agilent had just announced their new M9391A PXI vector signal analyser (VSA) a few days earlier. This product, along with its sister, the M9381A vector signal generator (VSG), shows that Agilent is serious in bringing new capabilities to PXI and the marketplace. Together, they form a powerful offering aimed at wireless communications. Equally important, there are additional software products, which I will get to shortly.
Like the M9381A VSG, the Agilent VSA is focused on delivering speed simultaneously with wide bandwidth and high signal fidelity. Built around a custom synthesiser and DSP ASIC, the VSA performs fast tuning and real-time data corrections. Couple that with the speed I reported earlier from the VSG, and you have one very fast test set for component test. The VSA is offered at a lower entry price if you want just 40 MHz bandwidth up to 3 GHz, suitable for many cellular applications. Like the VSG, it can be updated at a later time, through a software licence, up to 160 MHz bandwidth and to 6 GHz.
While I describe National Instrument’s software offering as LabView-centric, I’d describe Agilent’s strategy as automation environment agnostic, while adding their own measurement science. Essentially they are supporting automation programming from all environments equally (Microsoft Visual Studio, Agilent VEE, Matlab, Lab Windows, and LabView) through the use of IVI and LabView drivers. But for RF applications, they are leveraging their suite of measurement science software products. This includes Signal Studio for the VSG and the 89600 vector signal analyser software for the VSA. Additionally, they announced two new offerings. For the VSA, they have introduced the Modular X-Series Applications. These are the exact same measurement algorithms that run on their X-series signal analysers. For the VSG they’ve developed new baseband development software called the M9099. Agilent believes that the compatibility model they have of bringing the exact same measurements, via their software, from traditional instruments to modular ones is a compelling value proposition. It allows a user to choose their traditional instruments for one application, and their modular instruments for another, and know that they will deliver the exact same measurements.
But the surprise at the show was something not announced in their press kit: MIMO support. In Agilent’s demo room at the show there it was: a 2×2 MIMO system in a PXI chassis. In an EDN exclusive, the first photo of the system is published above; in a single PXI chassis, there are two pairs of PXI VSAs and VSGs. 4×4 systems can be created using a second chassis. The system comes with the associated software.
This was not Agilent’s only introduction, as they also introduced an AXIe-based M8192A Synchroniser module. This allows up to 12 channels of the M8190A AWG (arbitrary waveform generator) to be phase-synchronised together. The M8190A outputs 12-bit waveforms at 12 Gsamples/sec or 14-bit waveforms at 7 Gb/sec. Often these signals are upconverted to the microwave spectrum, but the M8190A has enough bandwidth and processing to meet some applications without upconversion. Multichannel synchronisation enables applications such as multi-element radar or receiver test.
AXIe got quite a boost at the show when two vendors announced development tools for this emerging modular standard. AXIe is commonly described as the “big brother” of PXI. That is, it acts like PXI, but has a much larger board format. Up to now, there were no development tools for AXIe, and certain aspects were daunting. To address this, Elma Electronic and Hiller Measurements simultaneously announced tools to help vendors, system integrators, or end users develop AXIe modules.
Elma is offering an IPMI controller, a key part of AXIe bus management, and an important part of module development.
“IPMI and IPMB bring robust management capabilities to AXIe and AdvancedTCA, but developers shouldn’t have to become IPMI experts to implements their designs,” Ram Rajan, V.P. of Engineering for Elma, told me. “With our expanding set of AXIe products and tools, they won’t have to, and can focus on delivering value to their customers.” Elma said they were also offering shelf managers, and even AXIe chassis in the near future.
For AXIe module developers requiring a more turnkey development environment, Hiller Measurements announced the MiAXIe AXIe Development System. The product provides the hardware and software interfaces for an AXIe module that can be quickly adapted to a customer’s application. Jeff Olsen, V.P. of Sales & Marketing at Hiller Measurements, noted the importance of this capability in aerospace and defence applications. “The recent introductions of high fidelity AXIe sources and receivers highlight the need for a flexible development environment to accommodate custom signal conditioning and up/down conversion. Similarly, legacy systems fielded in VXI can be ported to AXIe to address obsolescence in a cost effective and low risk fashion.” VXI remains a key platform for mil/aero applications, so it is interesting to note that system integrators who need a large format board standard have multiple options going forward.
I met Lauri Viitas from Guzik Test and Measurement at the show. Guzik has a number of AXIe digitizers, each at a 40 Gsamples/sec cumulative rate. (1 channel at 40 Gsamples/sec , 2 channels at 20 Gsamples/sec, or 4 channels at 10 Gsamples/sec). Guzik is also introducing an AXIe DSP module, called the DP6000. All modules will have a 40 GB/sec (320Gb/sec) local bus interface and x8 PCIe Gen 2 interface. In full disclosure, Lauri and I presented a joint paper at Autotestcon on AXIe local bus capabilities. You can read more about the local bus, in its particular attributes, here.
Despite getting a little old in tooth (like its inventors), VXIbus has a considerable footprint in the mil/aero test industry. These test systems have exceptional longevity, and the rule is if it isn’t broke, don’t fix it. VXI has the deepest depth of any of the three modular standards. For rack mounted systems this translates into more circuitry per rack inch, an important metric. The specification was recently updated to version 4.0, which adds PCI Express functionality and additional power. Though Agilent has transitioned to AXIe for its large format standard, most VXI vendors have either stayed with VXI or have augmented it with PXI.
I spoke with Fred Bloennigen, CEO of Bustec. They’ve developed a VXI 4.0 chassis, and are still adding new modules to their portfolio. Fred told me that the board size and bus speed is a good match for their applications, which are primarily data acquisition systems that measure physical parameters such as temperature, noise, and vibration. They’ve developed a platform strategy of developing new functionality on mezzanine cards that can plug into a faceless LXI instrument or a VXIbus carrier. One development addresses both platforms, and the software is identical between the two. The same plug and play software drivers control both variants. Being register-based, they are able to get very good interactive speed from the instruments.
I also spoke with Tom Sarfi, Modular Products Manager at VTI Instruments, and president of the VXIbus Consortium. VTI offers both VXI and PXI instrumentation. Their VXI portfolio is focused on mil/aero program business, and new developments would be in response to new programs. However, earlier this year they introduced 41 new PXI Express products, addressing switching, dynamic signal analysis, and electronic test. I was intrigued that they offered a number of portable test platforms that accept PXI modules. One touch panel tester incorporated four PXI slots at the top of the tester. This is a good example of how the small size of PXI enables hand carried test sets.
Teradyne is a long time VXI vendor in the mil/aero industry. Though they have a wide set of instrumentation, they are probably best known for their digital subsystems. Their M9 Series of digital instruments offers digital functional test capabilities in a C-size VXI form factor. Recently they augmented their VXI offering with a PXIe-based High Speed Subsystem they dub the HSSub. It is focused on mil/aero applications requiring high speed and custom serial bus testing. Essentially the high speed modules are placed in a PXIe chassis, but the tests are downloaded over LAN using LXI protocols. The heart of the system is a real-time processor embedded in the chassis along with a customisable Xilinx Virtex-6 FPGA. Many serial protocols require intelligent closed loop control, dependent on the specific data coming from the data, unaddressable by standard test vector techniques. The real-time processor and FPGA are designed to address these buses.
Finally, I met with EADS, another well-known VXI vendor. Over the past years they have acquired the Racal and Talon instrument lines, creating an impressive VXI offering. They keep the Racal and Talon brands on the modules, though the chassis is labeled as EADS. They have also incorporated PXI into their systems, and showed the Agilent PXI RF suite in one of their testers.
There’s an interesting dynamic being played out between PXI, VXI, and AXIe. While PXI clearly has taken the lead in the modular standards arena, a significant portion of the vendors believe a large format standard also has a place in the portfolio of options, whether VXI or AXIe. I’ve developed in all three standards, am currently a member of all three consortiums, and I also believe this is the case. The option of a large format open standard enables even a greater portion of the industry to be addressed by modular instruments, with all of the associated benefits. This is not necessarily the case for all product categories.
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