General DataComm CSU DSU
Automatic data rate and interface selection
2.4 to 64 Kbps
DeskTop 500A DSU
Universal Rate DSU for
• Handles all
digital service speeds from 2.4 to 64 Kbps for greater
• Automatic data rate and
interface selection for simple service upgrades
• Powerful diagnostic testing
capabilities for rapid fault isolation and
• Extended dynamic range for the
best performance possible
• Anti-lockup feature for
trouble-free clear channel operation
DeskTop 500A (DT-500A) is a universal rate data service unit
(DSU) for remote site locations in digital networks. It supports
all standard subrates and both 56 and 64 Kbps (clear channel)
high speed rates. Designed for easy "plug-and-play"
operation, the DT 500A simplifies both initial installation and
any future service upgrades. This highly reliable,
feature-packed product combines superior performance with a
sleek, compact design that is perfect for any remote or
satellite office environment.
Easy Installation and
Maintenance The DT 500A is configured using simple,
clearly marked switches on the bottom of the unit. The optioning
information is contained in a chart placed next to the option
switches. There is no need to wrestle with complicated prompts
or confusing menu trees, or plow through a detailed instruction
manual. The unit can be pre-configured and then delivered to the
remote site for plug-in installation.
Automatic Rate Selection
Service upgrades are virtually transparent to the user --
including upgrades between subrates and from subrate to 56/64
Kbps operation. The unit automatically adjusts its operating
rate to match the incoming signal and selects the appropriate
V.35 or EIA/TIA-232E interface. There are no bulky and expensive
adapter cables to buy and no need to change the unit's internal
printed circuit board.
The DT 500A includes a variety of features to ensure that system
faults are quickly isolated and resolved. First, the unit can
determine whether or not the transmit and receive pairs of the
digital facility have been transposed. This feature alone will
save hours of wasted troubleshooting.
Another unique capability is the Error Free
Seconds (EFS) test, which can be set to run automatically (e.g.,
overnight). This allows the user to confirm that the service is
performing within telephone company specifications.
The DT 500A also features three different
Remote Digital Loopback (RDL) tests, ensuring diagnostic
compatibility with many other 500-type DSUs. Tests are initiated
via dedicated front panel push buttons, and the results are
shown in an easy-to-read Electronic Display Window.
The DT 500A includes GDC's Extended Dynamic Range feature that
assures trouble-free operation, even over lines with very low
signal levels, such as unusually long subscriber loops. In 64
Kbps clear channel operation, an anti-lockup feature protects
against remote CSU/DSU lockup in permanent loopback -- a
condition caused by data signals that look like in-band loopback
The DT 500A incorporates powerful VLSI and
microprocessor technology, so it consumes very little power,
resulting in low heat dissipation and longer component life for
many years of reliable performance.
301-924-7400 EXT 25 / 301-924-7400 EXT 25 / fax 301-924-7403
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