外文翻译双速MILSTD1553B兼容光纤数据总线.docVIP

A DUAL SPEED, MIL-STD-1553B COMPATIBLE FIBER OPTIC DATA BUS M.S. Blaha. C.H. DeGennaro, S.F. Utley ATT Bell Laboratories Whippany, New Jersey 07981 Abstract A demonstration system of a dual speed, fiber optic data bus is described. This work is based on a previously described concept (1) which envisioned a data bus populated with MIL-STD-1553B avionic components which evolve as equipment is upgraded to higher data rates. The approach described herein provides for the coexistence of bus nodes operating at 1 Mb/s, and 20 Mb/s, on a single fiber bus medium. The 1 Mb/s interface of each node is 1553B compatible, making use of readily available hardware and software. Both existing, 1 Mb/s 1553B compatible interfaces and new equipment operating at 20 Mb/s have been shown to work simultaneously on the single bus structure. The design provides a sound, low-risk method for transitioning from current 1Mb/s equipment to a unified bus structure incorporating both existing 1553B compatible components and newly designed higher speed equipment. Introduction The ATT Fiber Optic 1553/MSDRT Data Bus provides an efficient means of improving the data handling capabilities of the 1553B data bus. Through the use of fiber optics and high speed digital multiplexing techniques, a single fiber optic bus can provide both 1 Mb/s and 20 Mb/s transmission capability when supported by 1553B bus hardware. The 20 Mb/s operation is based on the Multiple Speed Data Rate Transmission (MSDRT) concept, which involves multiplexing 20 Mb/s data with standard 1553B protocol in a manner which is invisible to 1 Mb/s users. This dual-speed capability provides retrofit high-speed capability to existing systems based on 1553B, and allows for graceful system growth in the event of system upgrades. A dual speed single fiber transmission bus was chosen over an approach using separate busses for 1 Mb/s transmission and for higher speed transmission because the single fiber bu