Event Marking with the E4 allows real-time annotation of a session. Tapping the E4's button (<1 sec) during a session will illuminate the LED light (for 1 sec duration) and deposit a record in the session file of the button press time.
Note the LED appears blue during a streaming session and red during a recording session.
Event mark viewed in Connect
Event marks in the Empatica Connect session viewer appear as red lines running vertically through the graphs.
Event mark data file 'tags.csv'
The 'tags.csv' file contains a record of the time of each of the event mark times during a session. This file can be retrieved from a session ZIP after downloading the data from Connect. Each row in 'tags.csv' corresponds to a physical button press on the device; the same time as the status LED is first illuminated. The time is expressed as unix timestamp in UTC and it is synchronized with initial time of the session indicated in the related data files from the corresponding session.