Symmetricom SDU-2000, User Manual

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12713020-002-2 Revision D – April 2004 SSU-2000 User’s Guide 45
Product Overview
SSU-2000 Family of Modules
GPS Input Module
The GPS Input module is a one-port card that can only be installed in the SSU-2000
main shelf. The module is used to correct the frequency of the oscillator on the
Clock module. It monitors and reports the status and performance of the module
and radio signals that it receives. See
GPS Input Module , on page 162, for more
information.
You must install this module in slot A3 or A5; the antenna connectors J6 and J7 on
the rear panel are connected to these slots, respectively.
Composite Clock Input Module
The Composite Clock Input module conditions a composite clock input signal that is
used to control the frequency of the Clock modules. For more information, see
Composite Clock Input Module , on page 165.
When the SSU-2000 is in the Subtending mode, the module also produces a 4 kHz
synchronization signal that determines the phase of the composite clock signals
generated by Composite Clock Output modules. This signal ensures that the phase
of the composite clock output signals follows the phase of the composite clock input
reference signal.
Output Modules
E1 Output Module
The E1 Output module uses one of three 4 kHz clocks from the SSU-2000 main
shelf backplane to generate a phase-locked signal of 2.048 MHz. If the unit is
inserted into an SDU-2000 expansion shelf, a fourth 4 kHz clock (D clock) is
available. The phase-locked 2.048 MHz signal is used to generate a set of 20 output
signals for distribution to large networks. See
E1 Output Module , on page 174, for
more information.
DS1 Output Module
The DS1 Output module generates a phase-locked signal of 1.544 MHz using one
of three 4 kHz clocks from the backplane of the SSU-2000 main shelf. If the module
is inserted into the SDU-2000 Synchronization Distribution Unit (expansion shelf), a
fourth 4 kHz clock is available. The phase-locked signal generates a set of 20
output signals for distribution to large networks.
DS1 Output Module , on page 178,
contains detailed information on the module.
Composite Clock Output Module
The Composite Clock (CC) Output module can be installed in the SSU-2000 to
generate and monitor CC signals, monitor input reference signals, accept new
configuration data, and report status. This module provides 20 signal pairs (TTIP
and TRING signal pairs), which are referenced to the selected clock signal. For
more information, see
Composite Clock Output Module , on page 181.