Clynalia issues invoices from the app, on iPad or iPhone. Each invoice generates a billing record that the VERI*FACTU regulation requires to be sent to the Tax Agency straight away. Sending it requires the clinic's digital certificate, and the certificate never leaves the clinic: that is why the station exists.
The station is a Mac app that stays on at the practice. Every few seconds it checks for new records, sends them to the Tax Agency with the certificate and stores the answer. The practitioner's app then shows whether each invoice was accepted.
If the station is off, invoices are still issued and the records wait. The Tax Agency tolerates the delay but notes it; that is why the station must always be on.