PROCESS HISTORY DATABASE SYSTEM

PROBLEM TO BE SOLVED: To provide a process history database system capable of preventing generation of time-out due to the delay of client's response during the updating of statistical information. SOLUTION: Two history servers for collecting and distributing process variables as process history in time series and a client 40 for executing display, analysis and other data processing by using the data of the process history are connected by network communication. The two history servers have a duplex configuration of a master and a slave, respectively independently collect process data and store the process history, and asynchronously update the statistical information of a database. The history servers for acquiring the process history are switched so that the client 40 acquires the process history from the master history server 21 usually, and in updating the statistical information by the master history server 21, the process history is acquired from the slave history server 22. COPYRIGHT: (C)2009,JPO&INPIT