Input Modules - Symmetricom SSU-2000e User Manual

Chapter 1 Product Overview
System Components
The Type I Clock module reads measurement data from the Input modules,
provides frequency control of the oscillator through DDS circuitry, and generates
reference signals used by the Input and Output modules. For more information, see
Type I Clock
Communications Module
The Communications module serves as the user interface to the SSU-2000e. The
module command interface supports three EIA-232-C connections and one
Ethernet interface for communication with the SSU-2000e system. This module also
logs the unit events into non-volatile memory for inspection at a later date and
reports alarms as they occur. For more information, see
on page 154.

Input Modules

1-Port and 3-Port DS1/E1 Input Modules
The DS1 and E1 Input modules are available with both 1-Port and 3-Port
configurations. These modules receive signals and perform phase measurement
comparisons with the Clock modules that are installed in the SSU-2000e. The Clock
modules use this information to phase and frequency lock to the incoming signal.
The data may also be used for monitoring the frequency of incoming signals.
The DS1 and E1 Input modules accept the following signals: sine or square wave
(with frequency of 1, 1.544, 2.048, 5 or 10 MHz) or framed communications type
DS1 or E1. If the input signal is a communications type, the module monitors the
following errors:
Alarm Indication Signaling (AIS)
Bipolar Violations (BPV)
Cyclic Redundancy Check (CRC)
Loss of Signal (LOS)
Out Of Frame (OOF)
The module also extracts Synchronization Status Messages (SSM) from incoming
data. For more information, see
and 1-Port and 3-Port DS1 Input
GPS Input Module
The GPS Input module is a one-port card that can only be installed in the
SSU-2000e 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
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.
42 SSU-2000e User's Guide
Module, on page 150.
1-Port and 3-Port E1 Input
Modules, on page 173.
Communications
Modules, on page 164,
GPS Input Module, on page 182, for
12713140-002-2 Revision E – October 2006
Module,