A Comparison of Distributed Control and Command/Response Multiplex Systems.
Abstract
This report contains the results of a study made to compare two different multiplex philosophies for the transfer of avionics information within military aircraft. One of these philosophies, termed command/response, concerns a digital time division multiplex (TDM) technique in which the data bus is under strict, centralized control. The other philosophy, also digital TDM, is based upon distributed control of the data bus through the application of a polling/contention technique. Although the two philosophies themselves can be compared, specific system architectures must also be introduced to facilitate a more comprehensive analysis. Of the numerous system architecture, the models chosen in this report to exemplify the two multiplex philosophies are the systems described in the proposed DOD standard MIL-E-XXX and the proposed NAVAIRDEVCEN specification for a General Aircraft Multiplex System. These systems were chosen because they essentially embody the most recent thinking of the military services in the areas of command/response and distributed multiplex systems, respectively. The systems are compared with respect to certain key items such as system architecture, method of bus access, etc. After the characteristics of each system are described with respect to each key item, the significance of the differences (and similarities) between the command/response system and GAMS is discussed. This latter discussion appears for each key item under the title of System Impact.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 08, 1975
- Accession Number
- ADA025105