Curtiss-Wright's VPX-REDI Boards Deliver a New Level of In-the-Field Maintenance to Open Standard Boards and Systems

In today's deployed defense and aerospace environments, it is generally accepted that the cost of sustaining a complex weapons system over its lifetime will be many times its upfront cost. A large part of that sustaining cost is the cost of repairs - not just the actual repair operations themselves, but the logistics tail of mobile repair shops and spares holdings. In recent years, a better approach toward battlefield maintenance has emerged, which utilizes Line Replaceable Modules (LRM) to speed, simplify and significantly lower the cost of system repair. At Curtiss-Wright Controls Embedded Computing, we're helping to drive the move toward LRM maintenance through our leadership role in bringing rugged, ESD (electro-static discharge)-protected VPX modules to the embedded COTS market.

The innovative LRM approach promises to greatly reduce the logistics burden by removing and replacing modules such as pluggable processing and I/O boards directly at the platform; this eliminates the traditional step of first removing the system-level "black box" and sending it back to a depot for the eventual replacement of a pluggable circuit board. By designing a system around the concept of LRMs, and holding spares at the LRM level instead of at the box level, the cost, volume, and weight of spares holdings can be reduced.

Historically, the military has employed as many as three (3LM) or even four levels of maintenance. With 3LM, the maintenance levels consist of the organizational level (O-level), the intermediate level shop (I-level), and the depot level. O-level is typically the field environment. In the 3LM approach, electronic system faults are isolated to the line replaceable unit (LRU) or subsystem, level. The entire LRU is then removed and replaced (R&R).  Next, the failed LRU undergoes troubleshooting and R&R of faulty circuit cards at the I-level. The faulty cards may then be sent to the depot for repair. This approach requires the costly sparing of complete LRUs with all related weight and volume. 3LM also requires the expense, vulnerability, and transportation of the I-level shop.

LRM: The Better Way

An alternative approach to battlefield maintenance, that reduces the cost and sparing complexity of 3LM, is to upgrade or replace electronics at the LRM level. The LRM approach eliminates the need for an I-level shop and slashes the high cost of sparing complete subsystems. Now, with the development of the new VPX and VPX-REDI board and backplane standards, defense and aerospace system integrators who increasingly desire the performance and cost benefits that COTS technology offers, have access to a COTS solution that addresses the real-world issues that emerge when electronic subsystems need to be repaired or maintained in harsh environments such as those typically found on the deck of an aircraft carrier, where electrostatic discharge (ESD) can easily ruin a module.

VPX's Integrated ESD Protection Enables LRM

Improper handling and ESD are serious threats to deployed boards and systems. ESD exposure, brought on by handling unprotected boards in static-rich environments such as the deck of an aircraft carrier can easily damage sensitive electronics. To support the LRM concept, circuit boards must be designed such that they can be removed and replaced in the field without special training or tools. LRM modules need provisions for protection against rough handling and ESD. They also require fault isolation down to the module/card level. The newly-defined VPX-REDI standard, also known as VITA 48, (a complement to the VPX/VITA 46 specification) collaboratively developed by Curtiss-Wright, prime military integrators and other COTS industry leaders, provides the first open standard approach for designing 6U and 3U boards that meet all of the LRM requirements including ESD protection, handling protection, and module level fault isolation.

VPX-REDI defines the use of protective metal covers which also provide stiffening against vibration damage. The new standard also specifies a new high bandwidth connector, the 7-row MultiGig RT-2 blade style connector that provides built in ESD protection by routing any static discharge (e.g. from maintainers' hands) into the connector away from sensitive electronics.

Besides providing excellent signal integrity for high-speed signals, VPX's MultiGig connector's size and modularity enables it to be mounted on a standard 3U or 6U x 160 mm card size and still allow a standard length PMC or XMC (VITA 42) to be hosted. The connector has also been proven to function reliably in harsh environments, including high shock and vibration environments (a connector and module test program conducted by the VITA 46 Working Group is documented in a detailed report available from the VITA website at www.vita.com). Even better, the MultiGig connector provides an integral mechanism to protect the signal contacts from ESD discharge. A unique ground-strip element on the connector acts as a miniature "lightning rod" for any ESD sources, ensuring that any signal contacts are not struck by ESD directly. The MultiGig connectors have the ability to withstand a discharge of 15 kV (as defined in ANSI/VITA 47). VPX also provides the safety ground required by LRM 2LM. VPX alignment hardware connects to ground any exposed metal on the module in order to eliminate electrical shock hazards caused by shorts to the metal.

VPX-REDI also defines extended mechanical formats applied to the overall board outline and connector system. These extended mechanical formats include versions with full top and bottom protective metal covers that provide the handling capabilities required to support LRM maintenance.

LRM Single Board Computers

Curtiss-Wright has already introduced two new COTS single-board computers that support LRM maintenance requirements. Curtiss-Wright Controls Embedded Computing announced the industry's first single board computer, the VPX6-185, and DSP engine, CHAMP-AV6, based on the new VPX-REDI standard earlier this year. The Freescale 8641 single/dual-core PowerPC-based 6U VPX6-185 delivers a nominal backplane bandwidth of 8 GB/sec via four Advanced Switching Interconnect (ASI) ports and features two PCI Express VITA 42 XMC/PMC sites, Gigabit Ethernet (GbE), serial ports, and mass storage interface options. The CHAMP-AV6 features quad PowerPC 8641 processors. These Curtiss-Wright boards are built to the Level 300 ruggedization level which includes VPX/VPX-REDI features plus additional enhancements to support LRM 2LM. For additional information on these products click below:

• VPX6-185 Single Board Computer 
• CHAMP-AV 6 Digital Signal Processor