Multitech MT56DSU-R, Owner'S Manual

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MT56DSU-R Owner's Manual
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1.4 CSU/DSU Basics
A DSU (Data Service Unit) and a CSU (Channel Service Unit) are
typically connected to provide the interface between a DTE (data
terminal equipment) and the DDS (Digital Data Service) or other
four-wire network.
The DSU is used to process serial synchronous or asynchronous
digital data over the DDS network or other four-wire unloaded
twisted-pair wiring network.
The MT56DSU-R can transmit data at 56000, 19200, 9600, 4800
and 2400 bps in multi-point and point-to-point applications.
The MT56DSU-R contains the functions of a Data Service Unit
(DSU) and a Channel Service Unit (CSU) in a single package.
1.4.1 DSU Functions
The DSU encodes data as pulses on the communications line by
converting the customer data stream to bipolar format for
transmission over the digital network.
1.4.2 CSU Functions
The CSU is used to terminate the digital circuit at the customer site.
It performs line conditioning functions, ensures network compliance
with FCC rules, and responds to test commands (either from the
telco central office (CO) or from the CSU).
The figure below shows the MT56DSU-R in a basic DDS network
installation.
Figure 1-1.
Basic DSU/CSU Configuration
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