The embedded market has focused primarily on the need to standardize the use of COTS processing add-in modules as part of the VPX suite of standards. Currently, the system designer treats the power supply as a necessary evil that is often an afterthought. Similarly, at times some of these module suppliers provide ad hoc solutions that system developers must implement. Providing power for these systems has historically been left up the module vendor, requiring them to define what has, at times, been seen as a form of "black art." The new VITA 62 standard, however, will define a set of rules by which industry power supply vendors can build COTS products, for VPX systems, that will fit into VITA 62-compatible backplanes. Consequently, system developers can have multiple vendors for power supply modules.
Though the initial focus of the committee is to define modules for VPX systems, the standard may also be extended into other form factors. To meet this goal, the VITA 62 committee is evaluating a proposal by industry for a standard power supply connector for the backplanes. The goal of the connector is to mechanically fit within the envelope defined in VITA 46 for the 6U and 3U add-in modules. This will facilitate the production of backplanes and allow system designers to define where and how many power supply cards are to be used within any given system.
VITA 62 modules compatibility
In addition to being mechanically compatible with VITA 46, these units will also support the various data requirements provided on the pinout connector of the VITA 46 module. This will support such things as VITA 46.11 chassis management, as well as provide spare data connections for slot-to-slot communication between add-in modules within the system.
The VITA 62 modules will also be compatible with the electromechanical requirements defined in VITA 48, thus ensuring complete functionality of VITA 62 cards in all targeted platforms. Additionally, the cards are expected to comply with VITA 47 to ensure harsh environment survivability in many of the deployments they will encounter.
VITA 62 planning
The variety of systems targeted for VITA 62 ranges from airborne systems using 115 VAC 400 Hz power, to ground-based embedded systems running from 28 VDC. To meet this challenge, the committee is investigating the need to define multiple card solutions that will provide for input filtering and power sourcing for the backplane. The committee will also address the need of fault tolerance by providing guidelines and recommendations on interconnection strategies to parallel power supply outputs as well as provide for N+1 failover. The committee is also looking to provide a warm swap capability, which will allow power supplies to be removed and inserted from a powered system.
Once in place, the VITA 62 standard will finally allow VPX system builders to procure COTS power supplies from a variety of vendors providing capabilities directly suited to their applications. This will allow the current fractured approach to power supply development to align under a standard and enable the provision of common resources to meet customer demands.
Patrick Shaw is the VITA 62 chairperson and can be reached at email@example.com.