Features; Physical Description - AT&T Callmaster Series Reference Manual

Modular Trunk Data Module (MTDM)
Similar in appearance and function to the TDM, the MTDM is a multi-purpose data module config-
ured to provide the digital switch interface to off-premises private line trunk facilities or a switched
network telecommunications network. The MTDM may also serve as a conversion resource for
modem pooling.
The MTDM can be configured to support the Data Call Setup, Modem Pooling, or Off-Premises
Data-Only Extensions features. In addition to the standard data transmission rates supported by
previous versions of the TDM (0.3, 1.2, 2.4, 4.8, 9.6, and 19.2 kbps), the MTDM supports data
rates of 56 and 64 kbps for downloading and other high speed data transfer requirements.

Features

The MTDM offers the following features:
Selected rates up to 64 kbps
Asynchronous rates up to 19.2 kbps
Synchronous operation at 56 kbps and 64 kbps
Full- or half-duplex operation up to 56 kbps
Full-duplex at 64 kbps
Self-test
Automatic answer
Private line and switched modes

Physical Description

Functional elements
Main module—Comes in one version that is common to all modular modules and pro-
vides the basic digital interface and protocol conversion functions.
Interface module—Provides an RS-232-C interface
Switches
ORIG/DISC
This switch is located on the front panel. It is used when originating and disconnecting
from a call for test purposes.
Trunk Data Module (TDM)
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