Specify the Location for Historian Data

You may set a specific location for the data and log files for your application using the application property, StorageLocation. Although the names of the properties are given here, these values should be set using the Historian tag's configuration panel.

The actual name of the property used is a combination of the Historian tag name and the keyword " StorageLocation ". Thus, to set a storage type for the SystemHistorian, you would set a value for "SystemHistorianStorageLocation ". For a tag named HistorianA,  "HistorianAStorageLocation ".

The default value is "History". If setting an alternate storage location for a file database, you should provide the full path to the folder that you want to use. The most common reason for this is if you want to save data to a disk other than the one on which VTScada is running. This could also be done by mounting an alternate disk to the Data\History path via MS Windows™. The constant disk usage associated with logging data from a large or medium sized application may cause a disk to wear out faster than it otherwise would. By keeping the data store separate from the disk that is running VTScada, and maintaining redundant storage on another server, you can lessen the impact of disk failure on your operations.

In tests, directing the Historian to save data to network share locations proved to be slow. Use caution if you intend to re-direct the location of the VTScada database to a .shared location on your network

If setting an alternate storage location for an ODBC database, you can provide either a Data Source Name (DSN) or a connection string.

The advantage of a DSN is that it is relatively easy to configure using the Microsoft ODBC Administrator™ dialog. The disadvantage is that you or your system administrator must create that DSN on each server that the application runs on.

A connection string is somewhat longer to create, but having been written, it may simply be copied to each server. Connection strings may be easier to maintain over the life of the application.

Support is also provided for FileDSNs.

Example using a DSN:

SystemHistorianStorageLocation = DSN=MyDSN_Name

Example using a connection string:

SystemHistorianStorageLocation = Driver=SQL Server; Server=ServerName;Database=DBName;Uid=user;Pwd=password