Much has been published about VPX topology, but where does one go to get started? If you purchase a complete system, many of the decisions are made for you, but what if you are developing your own application-optimized platform? Where is the best place to start? Fortunately, there is a support system out there that will take you through the process.
Before you start designing a system with VPX technology, you must understand the topology. “Helping to educate computer system architects on the options and the best choices are the first steps,” commented Michael Monroe, Product Specialist at Elma Bustronic. “Force the system architects to go through the pain of understanding topology.”
Getting started
“VPX is less likely to be plug and play,” according to Steve Gudknecht, Product Marketing Manager, Elma Electronic. “The backplane and module designs go hand in hand; there are challenges with the I/O and their respective connections.” To get through the challenges, collaboration with all pieces of the ecosystem is necessary, from the backplane to modules. Backplane suppliers are in the unique position of dealing with all aspects of the architecture and thus often the best place to start.
“We spend a lot of time studying the detailed specifications of system cards for I/O needs, understanding the potential areas of conflict between cards,” commented Michael. “The backplane suppliers know the tricks that can prevent costly changes during the development phase.” He went on to explain that the unique aspects of topology must be addressed from the very start. He continued with, “Every system is going to need a custom backplane!” How does one cope with the need to seek out a backplane that will meet specific needs?
“The boards used in VPX and the profiles defined by VPX are standard,” added David Hinkle, Field Applications Engineer at Elma Electronic. “But the topology can be tuned to meet the needs of the application.” Field application engineers spend a great deal of upfront time discussing the topology options that should be considered when developing a system.
|
|
In the age of specialization that is VPX, selecting from a list of three to four suppliers is no longer a good option. You must select a “prime contractor” and depend on their knowledge and skills to help direct you to the best solution. If you are going to go at it as an integrator, then choosing a backplane supplier is probably a good place to start.
Today’s backplane suppliers know the integration pitfalls. They understand and can steer you away from costly changes during development. They have had the experience of working with many of the module suppliers. Their understanding of topology architects is the most neutral. They have paved the way over many of the pitfalls that can exist if you are not properly prepared.
Steps to defining a VPX system
To help you get started, Figure 2 illustrates the steps to defining a VPX system. This process may be iterative as you start working through your options. It may also start at different points depending on your needs: either at the architecture level where the topology must be decided, or with a board with a specific functionality that will dictate the topology.
|
|
Several backplane suppliers have created white papers and guides to get you started. Elma Electronic has taken the steps to create a series of “Target Application Guides” that explain how payloads interact. The guides present issues to consider and nurture the system architects through the design stage:
- Identify the optimal starting board and its applicable slot profiles
- Recommend supporting boards based on their profiles and function
- Determine the backplane topology for data flow and application
- Identify a backplane profile based on standard backplane profiles
- Identify OpenVPX chassis profile for development or deployment
VPX backplane suppliers roundup
There are several companies that develop and supply backplanes for VPX systems. Customization is a key element of nearly all of the supplier strategies. What follows is a rundown of several of the suppliers and a look at what they have to offer. Most have experience in chassis and fully functional system integration that has provided them with backplane design and integration so critical to VPX systems.
Dawn VME Products (dawnvme.com)
Dawn has an extensive line of backplanes for the VPX marketplace. Dawn understands that system designers are challenged to meet application requirements while still adhering to the VPX standard. A cookie-cutter, one-size-fits-all approach is not going to work. Meeting the challenge requires an approach that uses innovative customization to configure systems comprised of VPX-compliant components.
Dawn is developing a new, soon-to-be-announced, “patent pending” technology. This new technology is supposed to allow customers to choose between a wide variety of available topologies at the time of order.
Elma Electronic (elma.com)
Elma Bustronic, member of the Elma Electronic group, developed the industry’s first VPX backplane and proposed the first VME pinouts to the VITA 46 subcommittee. Since then, Elma has developed various VPX configurations with and without VME64x legacy slots. VPX presents design challenges with higher layer-count backplanes and more demanding power and cooling requirements. Elma tackles these problems with signal integrity analysis, thermal simulation, and testing.
Hartmann Electronic (hartmann-electronic.com)
Hartmann Electronic has VPX covered with 3U and 6U backplanes from 3 to 10 slots and various mesh configurations, including hybrid VMEbus/VPX backplanes. With over 5,000 custom backplane designs to date, they have the experience necessary to help develop the right VPX backplane.
Curtiss-Wright Controls Defense Solutions – Hybricon (cwcdefense.com)
Early on, Curtiss-Wright Corporation saw the significance of backplanes to their VPX strategy so they purchased Hybricon Corporation in 2010 to expand their defense electronics subsystems portfolio. Hybricon was a leading supplier of high performance electronic packaging for the aerospace, defense, and commercial markets.
“The addition of Hybricon’s electronic enclosure technologies in our overall design and manufacturing portfolio expands our system integration capabilities and significantly enhances Curtiss-Wright’s ability to provide mission-critical rugged solutions to customers worldwide,” said Martin R. Benante, Chairman and CEO of Curtiss-Wright Corporation.
Curtiss-Wright continues to supply backplanes to the market and can help design custom configurations of VPX backplanes, ranging from 2 to 21 slots.
Pentair Electronic Packaging – Schroff (schroff.co.uk)
Pentair has a selection of VPX backplane products with new backplanes to be announced this year. They have the coding and alignment key for the VPX backplanes in tooling now. The pins will include the standoff, which prevents boards from getting plugged in upside down.
For the Titan ATR product line, Pentair has an interesting front panel and I/O transition board. They have created a transition board that is hard mounted to the enclosure front panel and that plugs into the backplane using high-density connectors. As the transition board is a plug-in unit, system maintenance is greatly simplified with no wires that can break during maintenance operations.
The solid-state, no harnessing design approach ensures optimal signal routing and maximum signal integrity. A custom transition board requires a custom backplane to mate with it. The backplane is designed with the same I/O characteristics, ensuring full matching of controlled impedances. Any required EMI/RFI filtering circuitry can be placed adjacent to the various I/O connectors, increasing the effectiveness.
Pixus Technologies (pixustechnologies.com)
The Pixus Technologies lineage includes Rittal and the former Kaparel Corporation. Pixus Mil/Aero systems customers, particularly for Command, Control, Communications, Computers, Intelligence, Surveillance and Reconnaissance (C4ISR) applications, are seeing performance challenges across the backplane to meet high-speed demands. The Pixus team often guides system architects through the VPX profile option process, helping to design customized backplanes based upon specific configuration profiles.
SIE Computing Solutions (sie-cs.com)
The SIE Computing Solutions lineage includes Mupac and Carlo Garvazzi, two noted backplane suppliers. SIE has vertical integration experience that is important in understanding the complete design process. SIE application engineers are experienced in assisting customers in the development of backplanes optimized for any application.
Working with backplane suppliers
Fortunately, anyone starting a VPX system integration project has plenty of resources to assist them through the process. Understanding the topology options that are best suited for your particular application is a very important first step, but don’t feel that you need to go at it alone. Backplane suppliers are a great place to start, as they have the experience and connections necessary to reduce the effort you need to complete your project. Be prepared to work with a supplier to have a backplane crafted that meets the requirements of your design.
|
|
(Click graphic to zoom)
|