The sequencing_summary.txt file is generated when basecalling is enabled during a sequencing run.
As of MinKNOW versions 20.06, this file will now be generated in the temp folder while the run is in progress and the file will be in a .tmp format.
On completion of the run, this file will be moved into the MinKNOW run folder. This change was made to prevent the issue of a truncated file, which could result under some run conditions.