Paradigm shifts in technology initiatives don’t come without their skeptics, as is the case with the DoD’s Hardware/Software Convergence Initiative. Aimed at developing a common, modular hardware architecture across C4ISR and EW systems, this program combines separate efforts initially undertaken by the U.S. Army under CERDEC (CMOSS), the U.S. Navy under NAVAIR (HOST), and the Air Force under AFLCMC into one, cohesive COTS-based, open standards initiative.
现在完全管理传感器开放系统体系结构（SOSA）, this collection of open architecture standards provides reconfigurable, upgradable, and cost-effective C4ISR capabilities in deployed platforms across sensor applications throughout all major military branches. Using OpenVPX as its basis, it’s setting the standard for interoperable systems across several defense branches to improve subsystem SWaP, enable rapid technology insertion, and promote reuse.
重要的是要了解OpenVPX在军事环境中的历史以及其作为批准行业标准的历史如何有助于促进这一广泛而又复杂的事业，从而摆脱了旧的昂贵专有计算系统的旧方法。
下面，关于OpenVPX的一些常见误解被消除了，我们研究了如何为SOSA倡议提供正确的环境
1. The card isn’t going to be compatible。
这取决于目标背板是VITA 65.0标准开发背板还是客户驱动的部署背板。VITA 65.0标准开发背板具有非常简单的拓扑结构，与大量卡兼容。实际的VPX系统背板具有许多I/O信号的复杂拓扑。
Consequently, these backplanes are usually designed for specific cards and map to the unique I/O mapping of one VPX module. With the development of fully defined SOSA VPX slot profiles, even complex backplanes will be wired for standard slot profiles, and the result will be more modules compatible with any given backplane implementation.
2. I won’t be able to get enough power。
Enough power is no longer the problem—it’s properly cooling the amount of available power. In the past, VME64x and CompactPCI cards could each typically draw no more than 150 W from a backplane slot. As large FPGA silicon became available from companies such as Xilinx and Altera, the power needs of an individual card exceeded the amount of power that a card could draw because the pin assignments and contact design did not allow for more power.
3U VPX卡可以吸引270 W，而6U卡可以吸引380W。由于功率可用性，VPX系统不太可能受到限制。而且，正在发布新的冷却标准，以允许将来在将来的系统中使用更多此VPX功率。
3. I’ll need a custom backplane。
One of the main criticisms of the VPX architecture, and a fair one at that, is that it doesn’t consider all of the other VPX features that have made the architecture so desirable. The mandate for custom backplanes is, therefore, being tolerated by designers.
一种新的解决方案旨在满足完全定制的VPX背板的需求。新兴的标准配置文件定义由SOSA领导下的勤奋技术小组开创，将消除对使用SOSA符合插件卡时针对特定，唯一的VPX模块的VPX背板插槽的大部分需求(see figure)。
这款3U OpenVPX背板是解决国防部CMOSS计划的模块的集成平台，为创建针对性能的系统创造系统的基础，并降低了交换和降低生命周期成本的快速技术插入。
4.我不能跑10 Gb / s的底板。
For some time, PCIe Gen2 and 10GBase-KX4 were thought to be the fastest protocols that could be reliably passed to I/O devices through cables, which plugged into VPX backplane RTM connectors. Recently, a new approach that utilizes new backplane materials, together with improved via design, has pushed this limit to PCIe Gen3 and 40GBase-KR4. It’s highly likely that a new, backward-compatible VPX connector may even allow these higher speeds to be exceeded in the near future.
5. VITA 65 may not meet all my design needs.
那些尚未审查当前添加到VPX的可用功能列表的人很可能会说。实际上，很难想象无法在标准内实施的应用程序。VPX坚固耐用，并支持两个卡尺寸。一些新功能包括微型同轴背板饲料，背板光学丝带，径向钟，25-GB/s通道，坚固的振动 - 耐振动连接器混合拓扑，XMC插座以及Vita 57.4 FPGA MEZZANINE，可支持28 GB的28 GB/s基板和夹层之间的链接。现在可用的同轴模块正在引起新应用程序的爆炸。
6. All of the VPX connectors are expensive because they are sole-sourced.
OpenVPX was built specifically with the goal of eliminating single-source pitfalls. To date, there are three suppliers of intermatable backplane connectors, one of which already offers three different versions of the VITA 46 connector. All versions are forward and backward-compatible.
The connectors cost more because of the performance they provide. These high-density, high-speed connectors allow space for XMC/PMC mezzanine sockets and fit within the 3U and 6U 160 Eurocard packaging formats. In addition, there are space-qualified, high-vibration-resistant, footprint-compatible VPX backplane/daughtercard connectors. Paying for the benefits of performance enhancement is true for whatever architecture you choose.
7.多连接器限制为12 GB/s。
Although the current connector supports signaling up 12 Gb/s, which is just beyond PCIe Gen3 and 10Base-KR Ethernet, a new backward-compatible version of the same MultiGig connector is being standardized and will support Ethernet lanes up to 25 Gb/s and Fat Pipes (FP) supporting 100GBase-KR4. This connector is both backward- and forward-compatible, so that old cards can be used in the new backplanes and new cards will be usable in the old backplanes. However, the speed will always have to be negotiated down to the least capable element in the path.
8.我无法检查现场的Vita 66.1/66.4光学模块。
There’s now an inspection card for 6U VPX conduction-cooled chassis that will automatically both inspect—and clean—VITA 66.1 optical modules installed in either the J3 or J6 position in a 6U VPX backplane.
独立于VPX系统，该工具被绑在笔记本电脑运行软件上，该软件将执行多次检查/清洁/检查周期，直到所有纤维满足检查要求。然后，可以将一张新卡插入现场检查的VPX插槽中。希望该设备将扩展到符合AV 48.1或AV 48.2的3U VPX插槽。
9.气流不与对流冷却相同？
Not at all. Three different cooling methods are actually included in OpenVPX that all depend on forced air. While technically not “new,” since these methods have been used with VME for years for demanding applications, they’re now standardized. Check out VITA 48.5, 48.7, and 48.8. Each offer advantages over conventional forced air, because each method allows air to be directed specifically where it’s needed.
10.我听说基于IPMI的VITA 46.11系统管理器的安全性还不够安全。
Your concerns have been heard, and the HOST and SOSA working groups are really beefing up the System Management approach and adding new capabilities, such as large file transfer support and IPMI 2.0 security. These two working groups are supported by a large team at the University of Georgia Research Institute, the U.S. Army, U.S. Air Force and NAVAIR, as well as individual companies and SBIR (Small Business Innovation Research) award winners. It’s a level of cooperation never seen before.
11. Can an intermediate frequency be shared between radio cards in a VPX backplane?I’ve heard that there isn’t sufficient isolation.
It’s true that the MultiGig signal pins may not provide sufficient isolation between pairs to distribute an intermediate frequency between radio cards. However, VPX slots now support a variety of coaxial interfaces that can distribute an intermediate frequency or very precise clocks such as Precision Time Protocol (PTP) and Network Time Protocol (NPT).
VITA 67.3 only defines the opening in the backplane, the mounting holes, and alignment pins, and supports several sizes of modules as well as a growing number of unique contact configurations, including mixed coax and optical interfaces. These 67.3 modules are easily removed and replaced on the backplane, so reconfiguration is possible.
VITA is working to standardize additional contacts, but users are already employing coaxial contacts such as SMPM (multiple suppliers), nanoRF (TE currently), and SMPS (SVmicro). SMPM (many vendors) is lower density, but it supports the greatest variety of backside cable options including flexible, semi-rigid, and right-angle terminations. Some SMPM configurations are already standardized within VITA documents.
我们只能解决背板方面，因为67.3是为了支持来自DaumperCard Mezzanines的直接发射的67.3，尽管也可以使用电缆。此外，VITA 67.3模块可以支持新的高密度纳米F和SMP触点。半尺寸的67.3个模块，具有多达12个同轴接触的模块已经在市场上并正在使用。密集的连接器目前仅支持柔性电缆。这些可用于分发已经提到的精确时钟。您还可以看到SMPM和Nanorf或SMP触点的混合物以及单个67.3模块中合并的光学MT Ferrules。
迈克尔·芒罗（Michael Munroe）是技术产品专家Elma电子Inc.
