Reads the current trend of a tag in waveform format. You must manually select the polymorphic instance to use.

Note This VI interacts with data in the Citadel database only.

Use the pull-down menu to select an instance of this VI.


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Inputs/Outputs

  • ci32.png timeout (30 s) —

    timeout specifies the maximum time, in seconds, that this VI waits for reading data from the Citadel database. The default is 30. A timeout value of less than or equal to 0 specifies no timeout, which means this VI waits indefinitely until this VI receives data from the Citadel database.

  • ci32.png max points per trace (all) —

    max points per trace specifies the maximum number of points to read from the database. This VI returns all available points of this trace in seconds before now in the following cases: max points per trace is less than zero.The number of the data points in seconds before now is less than the max points per trace. If max points per trace is zero, this VI returns no point for the trace. The default is -1.

  • cTag_Readerlvclass.png —

    Tag Reader in specifies the data of a group of tags that the Open Tag Reader VI opens.

  • c1dstr.png tag names —

    tag names specifies a list of the tags for which you want to read the historical data.

  • cdbl.png seconds before now (60 s) —

    seconds before now specifies a time interval between the start time and the current time. This VI retrieves the data in this time interval from the database. The default is 60 seconds.

  • cerrcodeclst.png error in (no error) —

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

  • cpath.png database URL —

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

  • cdbl.png interpolation interval (1 s) —

    interpolation interval specifies the interval, in seconds, at which this VI interpolates the data. The default is 1.

  • iTag_Readerlvclass.png —

    Tag Reader out returns the value of the Tag Reader instance.

  • i1dwdtint.png waveform graph —

    waveform graph returns a list of waveforms of the historical data of the specified tags.

  • i2di32.png quality —

    quality returns a list of the data quality of the traces that this VI reads from multiple tags. A value of zero indicates good quality. Refer to the quality output of the DataSocket Read function for detailed descriptions of the quality values. Use the Shared Variable Error from Quality VI to convert this code to an error I/O cluster.

  • ierrcodeclst.png error out —

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