Triggers are used to maintain strict timing of events in scanimage.
When triggers are used for controlling the start and end of aquisitions, they are knowns as Acquisition Triggers.
When triggers are used to timestamp significant events in an experiment, they are reffered to as Auxiliary Triggers
If timestamped experimental data needs to be encoded into the tiff header Information of acquisitions, then an I2C communication channel can be used.
To use the clocks coordinating acquisition in ScanImage, see the Exported Clocks