How to record a raw file with external trigger events?

Hello,

What is the correct procedure to record raw files with external trigger events?

When I record raw files either with metavision_studio, metavision_viewer or metavision_player, the recorded .raw file contains no external trigger events, as reported by metavision_raw_info. (see attachment).

I confirmed the presence of external trigger events via a small python program (see ext_trig.ipynb) that reads the events with
"triggers = mv_iterator.reader.get_ext_trigger_events()"

Any help is much appreciated!