An environment for process control tasks under RSX-11M

Computer programs for the control of industrial processes require specialized functions for the synchronization of their actions in real time. A real-time operating system can provide sertain of those functions but often only at a low level. A library of functions and auxiliary tasks was designed an implemented to allow tasks operating under the RSX-11M operating system to conveniently and consistently control respond to and control events in the an industrial environment.

Of particular concern were functions to serialize and synchronize many interrupts generated by a diverse set of sources. A means of presenting these interrupts to the user tasks was devised which masks the differences in the sources of interrupts while making available all the information represented by each interrupt.

The implementation was successful although it suffered from some inefficiencies inherent in the design of the underlying operating system.