Real time, fail safe process control system and method.

摘要

A real time control system is disclosed for controlling the sequential execution of scheduled operations such as in process control or broadcast scheduling applications. The system uses a fail safe feature characterized as a sender/listener architecture. An external clock input to the sender and the listener assures synchronous sequential stepping through identical schedules stored in each processor. Under normal operation, the sender processor controls the execution of events as they are sent from a host computer connected to the system. Unscheduled events or errors are processed by being added to the schedule in real time for both the sender and listener processors. The listener processor monitors the sender's signaling in the controlled network and, in the case of a failure in the sender, the listener immediately assumes control of the system as the new sender. The listener executes commands which were omitted by the failing sender during the takeover interval and it then resumes the originally intended schedule of process control events.