Motorola DDS/MR64, Installation And Operation Manual

Page: 11 / 69

DDS/MR64 1-1
Chapter 1
Introduction
GENERAL
The Motorola DDS/MR64 is a digital data unit that allows you to
connect your computer or other DTE unit directly to the digital network
without any other network access device. The unit pumps data at up to
64 kbps in point-to-point or multipoint applications. It combines the
functions of a data service unit and a channel service unit (DSU/CSU)
into a single compact unit.
In addition to offering Digital Data Service (DDS) operation, the DDS/
MR64 can operate as a short haul modem providing full-duplex, serial
data communications with either synchronous data from 2.4 to 64 kbps
or asynchronous data from 2.4 to 19.2 kbps over a privately owned 4-
wire, unloaded, twisted-pair cable system.
The DDS/MR64 is also capable of running asynchronous DTE rates of
38.4 kbps or 57.6 kbps over 56 kbps or 64 kbps lines, synchronous DTE
rates of 19.2 kbps or 9600 bps over 56 kbps or 64 kbps lines, and a
synchronous or asynchronous DTE rate of 1200 bps over a 2400 bps
line.
PHYSICAL DESCRIPTION
The DDS/MR64 is a standalone desktop unit. The front panel (Figure 1-
1) contains six Light Emitting Diodes (LED’s), three pushbuttons, and
an LCD screen. The rear panel (Figure 1-2) contains a power cord,
power switch, fuse, DTE connector, and a standard 8-pin DDS jack. The
DTE interface connects to the Data Terminal Equipment and the 8-pin
jack connects to the DDS line. Internally the unit contains one printed
circuit board.
FUNCTIONAL
The DDS/MR64 processes serial synchronous or asynchronous digital
data from the DTE for transmission over the DDS network or other
limited distance 4-wire, unloaded, twisted-pair cable systems. The
receiver contains an automatic equalizer which compensates for the
distortion and attenuation caused by the length of the line without any
adjustments by the user.