Reads historical data from the Citadel database and displays the data on an XY graph. You must wire a VI Server reference of this XY graph to the Trend Reference input to use this Express VI. You must place the Historical Trend Express VI inside a While Loop.


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Dialog Box Options

Inputs/Outputs

  • cpath.png Database URL —

    Specifies the computer name and the database name where the Citadel database resides. Enter the database URL in the format \\computer\database.

    For example, if you have a copy of the LabVIEW Datalogging and Supervisory Control (DSC) Module and Citadel service installed on a computer named datalogger and the name of the database on that computer is data, you can access the data on datalogger from another computer by using the path \\datalogger\data. If you provide a database name only, this VI searches for the database on the local computer. If you do not wire database URL, this VI reads data from the database associated with the default DSC Module process.

  • cerrcodeclst.png error in (no error) —

    error in describes error conditions that occur before this node runs. This input provides standard error in functionality.

  • catrn.png Start Time —

    Specifies the start time of the data to display on the XY graph.

  • catrn.png Stop Time —

    Specifies the stop time of the data to display on the XY graph.

  • cwgrn.png Trend Reference —

    Is the control reference to the XY graph.

  • c1dgenclassrntag.png Shared Variable List —

    Lists the shared variables to display on the XY graph. This list corresponds to the Added Historical Data Traces list in the configuration dialog box of this Express VI.

  • cu32.png Time Between Updates (s) —

    Specifies the refresh interval of the XY graph.

  • cdbl.png Relative Time —

    Specifies the range of data to display, in seconds, since the current time.

  • i1dcclst.png Historical Traces —

    Contains the array of historical data points retrieved from the database. Wire this output to an XY graph.

  • i1datrn.png timestamps —

    timestamps is an array that contains the time stamps of the retrieved data points.

  • i1ddbl.png data —

    data is an array that contains the values of the retrieved data points.

  • ierrcodeclst.png error out —

    error out contains error information. This output provides standard error out functionality.