Real-time control including concurrency. Part 1: Design

The design methodology CYBA-L is applied to the design of a concurrent control program for a real-time application ¿¿ an automatic print-roll cutter. The methodology partitions the problem into a control and a data graph; the control graph specifies the sequencing of the operations in the data graph. By a process of step-wise refinement the most abstract level of control, the front-panel operating algorithm, is hierarchically decomposed into the basic sequence of device operations needed to operate the cutter. The final design specifies the concurrency which may exist in the system