The Rockwell Collins CMU-900 provides the following capabilities:

• Delivers a state-of-the-art Data Link Communication Management Unit with no risk
• Provides compliance with industry standard ARINC Characteristic 758 installations. By complying to ARINC 758 characteristics the CMU-900 installs into the CMU equipment tray and supports the aircraft interfaces without modification
• Supports Iridium satellite Data Link communications
• The CMU-900 has been Type Certified by Boeing on most model types since 1999, with previous generations of equipment certified since 1990
• Provides fully compliant ARINC AQP and SITA VAQ testing and Boeing Commercial Aircraft Group (BCAG) FANS-1 Interoperability Requirements for Data Link Performance
• Supports VHF Digital Link (VDL) Mode 2 and Aeronautical Telecommunications Network (ATN) and ARINC 758 functionality as an end system hosting ATS applications; The CMU-900 is product Type Certified by Boeing for the advanced ATC Data communications being used in Europe today and is being updated to support the future European mandate
• Minimizes software update costs by providing isolated partitions for User Modifiable and non-modifiable functions
• Is developed and certified to the DO-160C and DO-178B Level D for ACARS, Iridium, VDL Mode 2, ATN and FMS FANS-1 routing operation
• Supports a completely modifiable AOC Application without certification impact
• Provides a powerful User Application Development capability allowing a customer the option of modifying and testing their own Data Link non-essential AOC application changes
• Provides a powerful PC based simulation capability extremely useful as a prototyping and training tool
• Minimizes cost of ownership by maintaining the Rockwell Collins tradition of exceptional reliability, as demonstrated by the DLM-700, DLM-900 and CMU-900 series of management units
• Proven integration with the Rockwell Collins HERMES or SITA Aircom ground systems for a complete end-to-end solution
• Is backed by the expertise and experience of Support, Service, and Engineering staff to assure successful Data Link integration and deployment

The Rockwell Collins CMU-900 is the newest generation Communications Management Unit; designed to satisfy Data Link Communication needs well into the future. The CMU-900 includes substantial CPU, Memory and I/O capabilities for the interfaces and functions specified within ARINC Characteristic 758.

The CMU-900 was developed to support ARINC 758 installations with a single software solution. Common software across a fleet will reduce the configuration management and administrative burden placed upon an airline.

The CMU-900 offers extensive policy routing tables for improved message routing. This permits management of Service Provider Preferences, Cost Indexes, and Performance Indexes (for priority control).

The CMU-900 provides considerable flexibility for control and display of information with the flight crew. Two types of CDU's are currently supported; ARINC 739 MCDUs and the ARINC 739 compatible Rockwell Collins IDC-900 Integrated Data Link Controller. A unique capability of the CMU-900 is its ability to communicate with multiple display devices concurrently. Updates performed on one MCDU will be automatically updated on the other MCDUs.

The CMU-900 is fully ARINC 615 dataload compatible. It supports partial and full loading via either a front panel for Portable Data Loaders or a fixed access via the rear connector for Automatic Data Loaders. Partial loading allows quick AOC-only application. Full loads allow all software components to be updated, such as when adding a new interface or capability.

The CMU-900 provides management of aircraft type configuration by utilizing an Aircraft Personality Module (APM). The APM-900 is fully compliant with ARINC Characteristic 607.

The CMU-900 includes all BITE interfaces for supporting any on-board maintenance systems according to ARINC 604 and ARINC 624. This includes internal fault detection, internal logging, as well as reporting.

A powerful application development tool, the CMU Ground Support Equipment (GSE) provides a tool for design, development, simulation, and testing of Data Link Airline Operational Control (AOC) applications. This includes design of screen layouts, printer reports, triggers, and message logic on a Windows PC. This tool also accommodates a common AOC across the airline’s fleet.

The major interfaces of the CMU-900 System include:

• The VHF/Satellite (Inmarsat or Iridium)/HF Subnetwork Interfaces that handle all Air/Ground Communication as defined in ARINC 618. Both Analog (using internal MSK Modem) and multiple digital (VDR Mode-A, VDL Mode 2) interfaces are supported for VHF. Communications management for simultaneous VHF, SATCOM, and HF channels is provided as well as advanced preference tables for use control of message routing over preferred subnetworks
• A CDU Interface which provides user control via multiple ARINC 739 MCDU's. Concurrent CDU access is also provided
• Printer Interface and spooler that will support printers conforming to the ARINC 597/740/744 printer protocols
• Peripheral interfaces for FMC’s, ACMS, CFDS, EFB’s, Network File Servers, and Cabin Terminals using ARINC 619 protocols
• A Discrete Interface which handles the analog input and output discretes and Program Pin information
• An ARINC 607 APM interface for programming and reading the aircraft unique information
• Independent AOC Application and Core software data loading through an ARINC 615 Data Loader
• Instrumentation port for debugging, simulation and test

A sliding plate on the front panel provides access to the data loader and instrumentation ports.

The CMU-900 includes a System Processor Card, a 429 Digital Card, an Analog Card, and a Power Supply Card. The distributed processing architecture allows slave I/O processors to perform the time critical tasks associated with communication protocols and other aircraft interfaces, freeing the system processor to perform high level processes.

A full-size growth card slot with access to the rear connector and system bus is provided. In addition, the 429 Digital Card contains provisions for a daughterboard for additional growth capability. This daughterboard may be accessed by the system processor and may also be used for additional I/O via the front panel.

Each slave card is memory mapped into a unique window of the master processor’s address space. Memory mapping gives the master processor access to all slave microprocessor busses and hardware, enabling extensive testing and troubleshooting capabilities. Each slave card will do its own address decoding. This maximizes the flexibility of each card, and reduces the number of interconnect lines required between cards.

A sliding plate on the front panel provides access to the data loader and instrumentation ports.

The basic CMU-900 software system is comprised of non-modifiable Core software and modifiable AOC data. The term 'non-modifiable’ is used to describe the fact that changes to this software would require a re-certification effort. The term 'modifiable’ is used to describe changes to Airline Operational Control (AOC) data that does not require a re-certification effort.

The non-modifiable section, referred to as the Core, contains all of the I/O drivers, protocols, modem functions, Built-In-Test, application functions, Run-Time Executive and inter-processor communication mechanisms.

The software architecture abstracts certain functions within the CMU-900 in order to comply with regulatory constraints and accommodate partitioning for co-existence of modifiable data and non-modifiable Core software. These elements will allow for improved system flexibility, lower maintenance, and the protection mechanisms to ensure that non-modifiable functions will not be adversely impacted by changes to modifiable data.

All embedded software has been developed to meet the requirements of DO-178B and all internal company standards for software development programs. Rockwell Collins software development standards are in compliance with the Software Engineering Institute (SEI) Level 3. All necessary documentation, configuration control, development and verification activities necessary to meet DO-178B requirements has been performed. The current CMU-900 core software has been certified to DO-178B Level D.