The Boeing 787 Dreamliner employs a revolutionary architecture called the Common Core System (CCS). This centralized system replaces the traditional approach of dedicated electronics for each aircraft function. Within the CCS, two critical components are the Common Computing Resource (CCR) cabinets. Let’s delve into the technical aspects of these cabinets, focusing on General Processor Modules (GPMs), redundancy, Fiber Optic Translators (FOX), and communication protocols.
General Processor Modules (GPMs):
- Each CCR cabinet houses eight GPMs. These modules are the workhorses of the CCS, acting as independent computing platforms.
- Individual GPMs host the operational software for various airplane systems. This software operates in a partitioned environment based on the ARINC 653 standard, ensuring isolation and preventing software conflicts.
- GPMs share a common hardware platform and core operating system. This standardization simplifies maintenance and reduces the need for specialized technicians for each system.
- Examples of functions hosted by GPMs include:
- Remote Power Distribution System (RPDS)
- Generator/Bus Power Control Unit (GCU/BPCU)
- Landing Gear Indication and Control
- Thrust Management Function
- Flight Management Function
Redundancy:
- A core principle of the CCS is redundancy. The Boeing 787 features two CCR cabinets, one on each side of the aircraft. This physical separation minimizes the risk of a single point of failure crippling critical systems.
- Each CCR cabinet also incorporates redundancy within itself. Dual Power Conditioning Modules (PCMs) ensure a continuous power supply for the GPMs. Additionally, the network switches and Fiber Optic Translator Modules (FOX) likely have redundant configurations for fault tolerance.
Fiber Optic Translators (FOX):
- FOX modules play a crucial role in communication within the CCS. They convert electrical signals used by the GPMs into optical signals suitable for transmission over fiber optic cables.
- Fiber optic technology offers several advantages over traditional copper wiring. It provides higher bandwidth, immunity to electromagnetic interference, and reduced weight, which is critical for aircraft efficiency.
- The FOX modules likely handle communication between the GPMs within a CCR cabinet and potentially connect the cabinets to other vital systems on the aircraft.
Communication Protocols:
- The CCS relies on the ARINC 664 network standard for communication between the GPMs and other network devices. This industry-standard protocol ensures compatibility and facilitates data exchange between various avionics systems.
- ARINC 664 utilizes a switched ethernet architecture, enabling high-speed and reliable data transfer within the CCS.
In conclusion, the CCR cabinets are the heart of the Boeing 787’s innovative CCS architecture. GPMs provide a flexible and standardized computing platform, while redundancy ensures system reliability. FOX modules facilitate high-bandwidth communication using fiber optic technology, and ARINC 664 ensures seamless data exchange within the network. This technical approach streamlines aircraft operations, reduces weight, and enhances overall system efficiency.
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