AT&T MERLIN LEGEND Release 2.0 Data User's Manual page 20

About Data Communication Equipment
The following digital data stations are supported.
Digital Voice and Digital Data. This endpoint
connects to the control unit via a 7500B Data Module.
The data module also has an attached MLX telephone.
The MLX port is shared by both the telephone and the
data station but they operate independently of each
other.
NOTE:
For a Digital Voice and Digital Data station, the
MLX telephone cannot contain a Multi-Function
Module (MFM). If you cannot communicate with
the switch, verify that the MLX telephone does not
contain an MFM.
Data Stations
1-10