The best way to run a railroad

In 1869 the Union Pacific and Central Pacific railroads joined their separate tracks to complete Americaís first transcontinental railroad at a location often called Promontory Point. In similar fashion – and after all the rhetoric slung by the embedded press from people such as myself and editor Sharon Schnakenburg – the working groups for VITA 65 (under VITAís VSO) and OpenVPX (originally conceived by Mercury Computer Systems) are now joined together. Gone is the fighting between Mercury and Curtiss-Wright Controls Embedded Computing (CWCEC) over the ìrightî way to build VPX boards. CWCEC has signed an MOU with OpenVPX and is on the 11-company Steering Committee.

The way this will work seems simple and aims to resolve the previous acrimony: OpenVPX and their 29 companies (the list isnít public yet) will create the system-level spec for VPX by the end of September 2009. By October, all that effort will be transitioned into VSOís VITA 65 Working Group headed by CWCECís Mark Littlefield. Even the OpenVPX logo, created by Mercury, will become the intellectual property of VITA, which previously hadnít made obvious overtures to trademark the existing VPX logo. But the seriousness, coordination, and surgical precision behind this born-as-OpenVPX-then-growing-up-as-VITA-65 speaks to the pent-up market demand for interoperable VPX boards and backplanes.

This is one reason that Boeing factors so heavily in OpenVPX, to the extent that Boeingís Bob Ford is the chair of the technical working group. The company has publicly committed to VPX and certainly wants to make sure theyíre not locked into a single vendorís VPX architecture. Even more importantly, already-designed prototype VPX systems will surely be going to LRIP soon – so itís imperative that system-level changes be handled sooner, rather than later. In fact, all OpenVPX companies had to agree to the strict timetable, which means committing substantial resources to assure the transition back into VITA 65 by the Fall.

But what will all those companies actually be doing under the OpenVPX unbrella?  There are four key goals:

n  Mechanical

n  Thermal

n  Electrical

n  Communications/topology

So far, all the hubbub has been about defining connector pins for backplane interoperability. This was the fundamental reason that OpenVPX was formed: VITAís own VPX specs contained 20 different ìdot specs,î from VITA 46 to VITA 46.21, many of which defined different pinouts and architectural topologies.

Another key goal, which is where the work will really start, is to define the various system-level topologies for how VPX is likely to be used. Symmetric multiprocessing, asymmetric multiprocessing, graphics, or sensor fusion systems will all require different interconnect schemes for moving data between cards in a VPX backplane. ìInstead of the thousand permutations,î says Doug Patterson of Aitech, head of the OpenVPX Marketing Committee, ìwe need to define the most likely ëbundlesí in Stage 2 of OpenVPX activities.î Right now the Working Group is only at the Investigation stage. Presumably, each bundle will represent a different type of flexible system topology. From there, pin assignments on VPXís gigabit Tyco MultiGigRT2 connectors can be specified.

But thereís more to OpenVPX than just the system connections. Itís quite possible that military requirements will have to be examined for two-level maintenance, liquid flow-through cooling, fiber optic connectors, and ballistic shock and vibration (such as for the space-qualified boards Aitech intends to build). These items drove OpenVPXís other two goals (mechanical and thermal) and could open up the can on VITAís own VITA 48 REDI, or the new connector investigations underway in VITA 60, 63, and 64. These two items might be bad news for vendors like CWCEC or GE Fanuc Intelligent Platforms, which are into high-volume production on existing VPX layouts. But CWCECís Littlefield says his company is ready for that with their ìsecond generation VPX product line.î

All this adds up to what Mercuryís Ian Dunn told us last month. OpenVPX is intended to address not only interoperability, but also all the system aspects of a VPX chassis. From user I/O, data, control, expansion, and utility planes, OpenVPX intends to mimic the successes of other industry trade groups like PICMG. And with a fast-track plan, supported by highly motivated companies who have contractually agreed to wrap this up by September 2009, the hand-off to VITA 65 will assure a smooth rail ride into ANSI certification. Once that happens, VITA will be the proud owner of a better VPX and one that will carry the VME ecosystem into the future.

Chris A. Ciufo

cciufo@opensystemsmedia.com