How does the NS track its consumers.

Hello

I am a student of the VU university, i am currently doing research regarding IoT and smartification within public transport. I wanted to ask exactly how the NS system works regarding checking in and checking out, how does the conductor check that you are checked in. Furthermore i wanted to ask how is the NS app connected within the system regarding emergencies and such. Is there perhaps a better platform to ask these research based questions?

Best regards