Reads the historical data for a group of traces using the specified time interval, up to the max points per trace specified. You must manually select the polymorphic instance to use.

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


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Read Traces Details

If you do not wire database URL, this VI reads data from the database associated with the default DSC Module process.

If you do not wire time interval, this VI returns all historical data for the traces, up to the max points per trace specified. If you do not wire max points per trace, this VI returns all points between the start and stop timestamps set in time interval. If you do not wire interpolate data, the DSC Module preserves gaps in the data as invalid (NaN) values. If you set interpolate data to TRUE, the DSC Module ignores the gaps, and the trace interpolates across the gap in the data.

Examples

Refer to the NIHyperTrend Graph XML Configuration.lvproj in the labview\examples\lvdsc\HMI Design\NIHyperTrend Graph XML Configuration directory for an example of using the Read Traces VI.