A function oriented design for industrial distributed real time control systems
Wolfgang A. Halang, Soon-Key Jung · Real-Time Systems Symposium · 1989
An architecture is described and a set of eight functional units is defined of which suitable asymmetrical distributed multiprocessor systems may be composed for any kind of application. Proceeding from the possibility of parallel activities, which is given in real time control applications on the task level, various general and specialised processors are introduced. Thus, a special module is provided for the essential task of process control, namely for task scheduling and event administration. It allows the employment of arbitrary scheduling conditions. The dispatcher manages the ready tasks according to a model with four stations and allocates the system resources under observation of a deadlock prevention scheme. Moreover, special modules are established for process communication and in order to drive the peripherals. In order to reduce the internal transmissions, which may become the main factor of the hardware price, the following measures are useful as well. Complex operations, especially for concentrating data, are migrated to the data sources and handled by application specific modules. Various functional units are furnished with private memories. Finally, the instruction address transfers are saved by the integration of the program address management into the program memory modules, where the instructions are already interpreted to a certain appropriate extent. >