Software Engineering Institute

Control system components are sensitive to the end-to-end latency and age of signal data. They are also affected by variation (jitter) in latency and age values due to different runtime configurations (i.e., sampling or data-driven signal processing pipelines, dissimilar communication mechanisms, partitioned architectures, and globally synchronous versus asynchronous hardware). This technical note introduces an analysis framework designed to calculate the end-to-end latency and age of signal stream data as well as their jitter. The latency analysis framework and calculations are illustrated in the context of an example model that uses the flow specification notation of the Architecture Analysis & Design Language (AADL). The report describes how this latency analysis capability can be used to determine worst-case end-to-end latency on system models of different fidelity and how it accounts for partitioned architectures. It also summarizes the worst-case end-to-end flow latency analysis capability provided by the Open Source AADL Tool Environment (OSATE) flow latency analysis plug-in.