Avaya Definity SI, Maintenance Manual, Page: 1969 / 2968

PDMODULE, TDMODULE (Data Module)
Issue 4 May 2002 10-1183 555-233-123
Figure 10-78. Typical Data Module Application
The MPDM provides an interface for Data Terminal Equipment (terminals), and
the MTDM (see Note) provides an interface for Data Communications Equipment
(transmission equipment such as modems).
NOTE:
Early versions of these data modules were referred to as PDMs and TDMs,
respectively. Later models are designed to provide various customer
interfaces through the use of interchangeable interface modules and,
therefore, are called modular data modules. Both versions are supported by
the tests described in this section.
The PBX loop or digital link between a data module and the Digital Line port
supports two logical information channels and one signaling channel. MPDMs and
MTDMs use the primary information channel for data communications and the
signaling channel for dialing and call supervision. The secondary information
channel can be used to support a second data module on a shared digital port.
Data modules are not only used for data calls between terminals, computers, and
data communications equipment, but are also used as interfaces to equipment
associated with system features such as System Administration, CDR, MCS,
ACD, DCS, and AUDIX. Maintenance tests for data modules associated with
those services are covered by tests other than those described here. (See
PI-LINK, PMS-PRNT/JNL-PRNT, and PMS-LINK Maintenance documentation.)
Switch
Digital line
circuit
pack
Digital line
circuit
pack
r11j1p1 LJK 072501
TDM
bus
MPDM
MTDM
Terminal
Host
computer
Loop
(digital link
information and
signaling channels)