From OpenSCADAWiki
Currently, one method is known when there is practical value from the data source's timestamp, which is the work with the history-archive on the side of the data source, when the data area of the archive-history is asked corresponding to this gap instead of the current-operational data, for example, when there is no communication. And this method is implemented in the module DAQ.DAQGate, when running OpenSCADA on the side of the data source or the PLC.