Sequencing date flow tasks in SIGNAL

Overview & Synopsis

The SIGNAL language is a real-time, synchronized data-flow language. Is model of time is based on instants, and its actions are considered instantaneous. Various application domains such as signal processing and robotics require the possibility of specifying behaviors composed of successions of different modes of interaction with their environment. To this purpose, we introduce the notion of time interval, defined by a start and an end event, and denoting the series of its occurrences. Associating a time interval to a data-flow process specifies a task i.e., a non-instantaneous activity and its execution interval. Different ways of sequencing such tasks are described. We propose these basic elements at the programming language level, in the perspective of extensions to SIGNAL. Application domains feature the discrte sequencing of continuous, data-flow tasks, as is the case, for example, of robotic tasks.