Indicates whether all trend history files should be created at startup or created when needed. By default, CitectSCADA creates all trend history files at startup, so that the required disk space is allocated at the same time, without fragmentation. (Because files are created at startup, you know the total disk requirements.) Creating history files at startup happens only once - the first time CitectSCADA starts up.
On large systems with many trends, the first startup could take considerable time. If you change the default of this parameter, history files are created whenever needed, reducing the first time startup delay. However, if a disk space shortage occurs while CitectSCADA is running, data loss will occur because new history files cannot be created.
Allowable Values:
Default Value: 1
See Also