12713140-002-2 Revision E – October 2006 SSU-2000e User’s Guide 43
Chapter 1 Product Overview
System Components
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 185.
In Subtending mode (either ANSI or Japanese), 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-2000e main
shelf backplane to generate a phase-locked signal of 2.048 MHz. If the unit is
inserted into an SDU-2000e 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 190, 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-2000e main shelf. If the
module is inserted into the SDU-2000e 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
194, contains detailed information on the module.
Composite Clock Output Module
The Composite Clock (CC) Output module can be installed in the SSU-2000e 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 197.
E1/2048 kHz Output Module
The E1/2048 kHz Output module can be installed in the SSU-2000e to generate
and monitor 20 independent E1/2048kHz output signals. If the module is inserted
into an SDU-2000e expansion shelf, a fourth 4 kHz clock (D clock) is available. If the
input signal PQL drops below a user-specified level, then the outputs can be
squelched. For more information, see E1/2048 kHz Output Module, on page 201.