Techniques for requesting and providing process plant data using a source-independent standardized query are provided. A requesting device generates a standardized query to obtain data from one or more data sources, such as relational or non-relational databases. The query utilizes a standardized format that does not depend upon the data source, which query may be generated as a JSON file. The standardized query may not be directly usable for any data sources. Instead, a data device generates one or more source-specific queries upon receipt of the standardized query. The source-specific queries utilize syntax native to each data source to obtain data. In some instances, the received data must be further processed to adjust for different sample times or sampling rates, such as by interpolation. The resulting data from all data sources may be aggregated into a data frame prior to being returned to the requesting device.