What is the requirement for remote maintenance?
Remote maintenance:
In the electrical cabinet a modem with a remote maintenance adapter is integrated. Therefore you can do small changes over the phone line.
Recommended is an analog phone line with a direct phone number, with no internal connection through a switch board.
CAUTION:
Disconnect the phone line, if not in service! The remote maintenance system depends on a very good quality phone network. A bad network will make the service impossible.