ARCHITECTURAL CONSIDERATIONS FOR A GENERIC MULTI-PORT DIGITAL INTERFACE

Abstract

Telemetry system requirements are driven by technological developments in other areas, thus the capabilities of one are mirrored in the capabilities of the other. Contemporary systems typically involve two or more digital subsystems, each operating at a unique clock rate; an increase in complexity that needs to be addressed by the Telemetry system designer. Although the subsystems may be exchanging information, complete synchronization is seldom realized in discrete systems. Because the Telemetry system must provide information sufficient to isolate data/process corruption, it must accept data from the various subsytems at different rates and times. What is needed is a technique to de-couple the Telemetry system clock rate from that of the Subject system or any of its subsystems. This technique must bridge the gap between the synchronous data transmission fundamental to the Telemetry system and the asynchronous data transfer required by the various non integrated subsystems. This paper will discuss the design challenges offered by such a Subject system for both real time and post flight analysis. It will discuss how the restrictions imposed by the IRIG standards and anticipated mission requirements factored into developing the architecture for a Generic Multi-Port Digital Telemetry Interface.