APPLICATION STATION(AS) USED IN PROCESS CONTROL SYSTEM, REDUNDANT MANAGER USED IN AS, METHOD AND SYSTEM FOR ESTABLISHING/MAINTAINING REDUNDANT CONTEXT IN PROCESS CONTROL SYSTEM(PCS) HAVING FIRST AND SECOND AS, MACHINE-ACCESSIBLE MEDIA WITH DATA STORED INSIDE, REDUNDANT AS SYSTEM, AND CONFIGURATION CHANGE METHOD OF AS

摘要

PPROBLEM TO BE SOLVED: To properly maintain a history parameter even during failure of an application station. PSOLUTION: This application station used in the process control system is provided with: a redundant manager; and a redundant link subsystem connected to the redundant manager. The redundant manager is so composed as to communicate with a second application station by using a redundant communication link. The redundant manager establishes a redundant context with the second application station to track the action of the second application station by using a redundant context. Additionally, the redundant manager receives information from the second application station by using the redundant link and the redundant subsystem, and switches over action from the second application station to the application station in response to the information. PCOPYRIGHT: (C)2004,JPO&NCIPI