Data Communications Components - AT&T MERLIN LEGEND Data Manual

Data Communications with This System

Data Communications Components

Individual Use Data Stations
Diagrams of voice and data equipment commonly connected to the system are
shown in the following pages. The numbers in the diagrams correspond to
numbers in the accompanying text on the facing page. The text explains what
the equipment is, where it's connected to the control unit, and how it's used to
make data calls.
Figure 1-1 shows configurations for an analog data station and a digital data
station, both intended for individual use.
1. Analog Voice and Analog Data includes a data station with an endpoint,
such as a data terminal or PC connected via a modem, and an analog
multiline telephone. A GPA supplies the tip/ring (T/R) interface for the
modem. To provide simultaneous voice and data calls, two adjacent station
jacks must be assigned on a 408, 408 GS/LS, or 008 module using a
BR-241-B1 bridging adapter.
2. On- or Off-Premises Analog Data-Only is an endpoint connected via a
modem, Connection to the control unit is through an off-premises telephone
(OPT) jack on a 008 OPT module.
3. Analog Data-Only is an endpoint connected via a modem to a basic station
jack on a 008 OPT or 012 (basic telephone) module in the control unit.
4. Digital Voice and Analog Data is an endpoint connected via a modem and
a Multi-Function Module (MFM) in an MLX telephone connected to the control
unit. The modem converts the digital signal to an analog signal that is sent
through the MFM in the MLX telephone connected to the control unit.
5. Digital Voice and Digital Data is an endpoint connected via an ISDN 7500B
Data Module attached to an MLX telephone. The ISDN 7500B Data Module
supplies the RS-232 interface to the endpoint. The MLX telephone connects
to a station jack on a 008 MLX module.
6. Digital Data-Only is an endpoint connected via an ISDN 7500B Data
Module. Since an MLX telephone is not attached, a 440A4 terminating
resistor must be installed. The data station is connected to a station jack on a
008 MLX module.
Data Communications Components
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