Hi Richard @hornoo,
Unfortunately with the Tobii EyeX, fixations are determined automatically without the option to fine tune the parameters.
This kind of functionality to access raw data, adjust fixation settings, etc is only allowed within the Tobii Pro range of eye trackers which are designed for scientific research.
The Tobii EyeX is designed for interaction and gaming only and long term storage of fixation or gaze data is prohibited according the Tobii EyeX SDK licence agreement.