56. An industrial system or the like comprising: apparatus for implementing system operations; sensor means associated with the apparatus for generating signals indicative of the state of the system; a digital computer system having a memory; signal scanning means associated with said computer system and connecting to said sensor means for scanning said sensor signals periodically and including means for transferring a digital record of the status of the signals into the memory of said digital computer system; at least one machine readable signal-related event definition defining as an event either the periodic scanning or a particular change in the state of at least one sensor signal, including a designation which serves as a name for the event and also as a name for the signal, and including a reference to the location in said memory where the status record of the corresponding signal variable is stored; at least one machine readable job definition including at least one triggering reference to a designation which serves as a name for an event and for a signal and which is at least one event definition; loader means for operating said computer system to accept said event and job definitions and to store said definitions in said memory; trigger-connect means for operating said computer system to link job definitions but only those containing trigger references to designations, to locations in said memory that are in turn linked to the event definition and status data for the designated signals; means for operating said computer system to respond to the occurrence of a signal-related event by initiating execution of any and all job definitions which are linked to the status data and definition corresponding to that event; at least some job definitions which contain data specifying how often they are to be executed; means for linking together within said memory at least some job definitions which are to be executed at the same rate; and means for periodically executing the jobs defined by all definitions in such a linkage which means follows the linkage from one definition to the next.
59. A system in accordance with claim 56 wherein at least some executable definitions are assigned identifiers; wherein scheduling means are provided to schedule execution of job definitions when supplied with job definition identifiers; and wherein a trigger linkage between a combined event and job definition in a linkage and a job definition to which an identifier is assigned is established by means which establish a linkage between the identifier and memory data relating to the combined event and job definition.