AT&T MERLIN LEGEND Release 2.0 Data User's Manual page 15

About Data Communication Equipment
Analog Data Stations
Analog data stations use modems to send and receive
information.
Modems convert outgoing digital signals from the data
terminal into analog signals for transmission, and convert
incoming analog signals to digital signals for the data
terminal. It may provide dialing and answering capabilities for
the data station, depending on modem features.
Except for an analog multiline telephone, a telephone
connected to a modem operates independently from the data
station. The modem handles the data call over the regular
telephone company network or with another data station
inside the system.
Data Stations 1-5