Operator lock-out in batch process control systems

摘要

A process control system includes module-level attributes that may be used to control access for writing information to unit module objects and module objects. A security check process examines the module-level attributes, which may include OPERMODE and OPERLOCK attributes, the values of which determine whether information may be written to unit module objects or module objects. The values of the module-level attributes may be controlled based on whether a particular module object is being used by the process control system.