CONFIGURATION DATA BASE SYSTEM, DISTRIBUTED CONFIGURATION DATA BASE SYSTEM, METHOD FOR STORING AND USING CONFIGURATION DATA, DATA BASE SERVER, METHOD FOR PROVIDING ACCESS TO DATA BASE COMPONENT, METHOD FOR USING DATA BASE SERVER FOR PROVIDING PARALLEL ACCESS TO COMPONENT STORED IN DATA BASE AND PROCESS CONTROL SYSTEM

摘要

PROBLEM TO BE SOLVED: To enable each of users at different positions to timely and safely change a configuration data base without conflict. SOLUTION: This system is provided with plural data bases distributed at plural physical positions inside a process control system and each of data bases stores the subset of configuration data. This subset can be accessed from the user on any arbitrary site inside the system. In order to prevent configuration data watched by a subscriber inside the system from getting old, the data base server automatically detects a change into each of items inside the data base and transmits the notice of the executed change to each of subscribers.