Increasing Scalability in MicroTCA Solutions

By Tom Roberts, Mercury Computer Systems

MicroTCA systems offer small, low-cost computing solutions that are flexible and powerful enough to address a broad set of demanding applications. However, they are currently limited in upward scalability. A new approach allows designers to combine multiple chassis, thus extending scalability considerably. 

MicroTCA was conceived as an advanced modular platform in a smaller, cheaper form than AdvancedTCA. It uses the popular AdvancedMCs as its base cards, providing a direct backplane connection between them. By eliminating carrier cards, it enables smaller, cheaper systems, but the available system bandwidth is lower than in AdvancedTCA because there are fewer fabric switches.

Like AdvancedTCA, MicroTCA is highly scaleable. Assume developers want to stick with a single hardware configuration to reduce design and test time, minimize inventory and parts costs, and simplify maintenance and upgrades. They can start by filling just a few slots in a chassis, thus keeping initial costs low. They can then fill more slots later, increasing capabilities to keep up with demand or adding new features. They can also provide a range of systems at different price points to handle varied requirements, thus easily creating a family of models differing only in the number of filled slots. For example, designers could create a family of transportation security baggage screeners. The different models would meet the needs of airports and other facilities with widely varying requirements and traffic. 

But what happens when all the slots are filled? One option is to switch to a larger chassis. However, that involves a significant re-design which is expensive and time-consuming. Also one loses the advantages of the single configuration, particularly with regard to test, maintenance, and upgrade. A more easily managed and more cost effective path is to start with a chassis that is inherently ready for scalability.

Ideally, this chassis would still allow designs to start small at an attractive, entry-level price point. The physical characteristics and system level interfaces such as buses and fabrics would remain the same throughout. Additional scalability would be achieved by simply linking together multiple instances of the basic chassis. This is a logical extension to the AdvancedTCA-MicroTCA building block approach of adding cards.

For example, Mercury Computer Systems has implemented this approach with its new 6-slot Ensemble 2000 Series MicroTCA chassis. It supports mechanical stacking in a 19-inch rack. The base interface (Gigabit Ethernet), fabric interface (choice of RapidIO, 10 GigE, or PCI Express), and clock can all be daisy-chained across multiple chassis. For further economy, switches are built into the chassis backplane to support both the fabric and base interfaces.

Such a small chassis, designed for a building block style of application growth, clearly supports highly scalable solutions. It allows designers to take an incremental approach to managing both future needs and ranges of industrial equipment. They can start small, then keep expanding almost indefinitely while retaining a single platform that reduces design time and parts cost while simplifying test, maintenance, and upgrades.

Tom Roberts is Product Marketing Manager at Mercury Computer. You can reach him at troberts@mc.com.