Symmetricom TimeSource 3100 User Manual

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TimeSource 3100

GPS Primary Reference Source

User Guide

Revision K – December 2005

Part Number 097-72020-01

Symmetricom, Inc.

2300 Orchard Parkway

San Jose, CA 95131-1017

U.S.A.

http://www.symmetricom.com

All product names, service marks, trademarks, and registered trademarks

used in this document are the property of their respective owners.

Table of Contents

Contents

How to Use This Guide

Chapter 1 Overview of the TimeSource 3100

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Global Positioning System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Physical Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Roof Antenna. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Antenna. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

IF Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Local Oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Clock Extractors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Power Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

NTP TimeServer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Network Time Protocol Password Activation. . . . . . . . . . . . . . . . . . . . . . . . . . . 23

BesTime Ensemble Timing Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

E1 or Analog Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Eight Mixed E1/T1 Outputs (990-72020-06 Systems Only) . . . . . . . . . . . . . . . 23

Eight Additional E1 Outputs (990-72020-02 Systems Only) . . . . . . . . . . . . . . . 24

TOD Output. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

IRIG-B TOD Outputs (990-72020-05 Systems Only) . . . . . . . . . . . . . . . . . . . . 24

1 PPS Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

10 MHz Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Two ESCIU Ports (990-72020-04 Systems Only). . . . . . . . . . . . . . . . . . . . . . . 24

Alarm Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Communications Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Ethernet. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Passthrough . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Alarm Programmability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Startup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Bridging/Holdover Behavior. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Time Figure of Merit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Chapter 2 Engineering & Ordering

Site Survey. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Lightning Suppressor Guidelines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Antenna Location Guidelines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Earth Ground Location Guidelines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Antenna Cable Choices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Remote Oscillator Cabling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

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IRIG-B TOD (990-72020-05 Systems Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

RJ-422–to–RJ-232 TOD Converter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Shelf Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Standard System (Two E1 or 2.048 MHz Outputs). . . . . . . . . . . . . . . . . . . . . . 40

With Eight Additional E1 or 2.048 MHz Outputs . . . . . . . . . . . . . . . . . . . . . . . . 41

With Eight Additional Mixed E1/T1Outputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

With Two E1 Synchronization Insertion (ESCIU) Ports. . . . . . . . . . . . . . . . . . . 42

With Four IRIG-B TOD Outputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

User-Supplied Tools and Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

For Antenna Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

For Shelf Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Outputs, Power, and Miscellaneous . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Chapter 3 Installing the TimeSource 3100

Unpacking the Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Installing the Antenna. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Installing the Shelf . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Installing Output Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Rack Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Making Cable Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Frame Ground. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Making Power Connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Making GPS Antenna Connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Making 10 MHz Output Connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Making E1 or Analog Synchronization Output Connections . . . . . . . . . . . . . . . 57

Making 1 PPS Output Connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Connecting E1 or Analog Reference Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Connecting Remote Oscillator Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Installing a Module for Additional E1 or Analog Outputs. . . . . . . . . . . . . . . . . . 61

Installing the Mixed E1/T1 Output Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

Installing the IRIG-B TOD Output Module. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

Installing the ESCIU Port Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Connecting the Time of Day Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

Making Ethernet Connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Connecting to Communication Port 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Connecting to Communication Port 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

Connecting Alarm Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

Making Craft Port Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

Powering Up the Shelf . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

Installing TimeWizard. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

Factory Default Values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

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Chapter 4 TL1 Reference

Conventions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94

Command Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94

Response Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

Autonomous Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

Report Alarm. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

Report Event . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

Tasks/Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

Commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

Activate User. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102

Cancel User. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

Copy Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104

Delete Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

Delete User Security. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107

Edit Communication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108

Edit Date . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

Edit Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113

Enter Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122

Enter User Security. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124

Initialize Log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125

Initialize Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126

Initialize System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127

Operate Alarm Cutoff All . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128

Retrieve Alarm All . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129

Retrieve Alarm Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130

Retrieve Communication. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131

Retrieve Condition All . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134

Retrieve Condition Equipment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135

Retrieve Equipment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136

Retrieve GPS Status. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143

Retrieve Header . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144

Retrieve Inventory. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145

Retrieve Log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147

Retrieve Performance Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148

Retrieve User Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157

Set Source Identifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158

Chapter 5 Troubleshooting

Troubleshooting with Front Panel Items. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160

Troubleshooting with Error Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164

Replacing Cards. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170

Returning the TimeSource. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171

Repacking the Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172

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Equipment Return Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172

User Guide Updates. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173

Chapter 6 Specifications

Antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176

Communication Ports. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176

Port 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176

Port 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177

Craft Port. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177

Ethernet Port. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178

Time of Day Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179

Network Time Protocol (NTP) Type 4, Format 2 Driver Format . . . . . . . . . . . 179

Cisco Systems Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180

IRIG-B TOD Outputs (990-72020-05 System Only) . . . . . . . . . . . . . . . . . . . . 181

Remote Oscillator Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181

E1 Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182

Analog 2.048 MHz Inputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183

1 PPS Output. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184

E1 Outputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185

Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185

Additional E1 Outputs (990-72020-02 System Only) . . . . . . . . . . . . . . . . . . . 186

Analog 2.048 MHz Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187

Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187

Additional Analog Outputs (990-72020-02 System Only) . . . . . . . . . . . . . . . . . . . . 188

Mixed E1/T1 Outputs (990-72020-06 System Only) . . . . . . . . . . . . . . . . . . . . . . . . 189

E1/T1 Common. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189

E1 Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189

T1 Outputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190

10 MHz Output. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190

ESCIU Ports (990-72020-04 System Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191

Office Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192

Connector Panel Contacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192

Front Panel Lamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192

Front Panel Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192

Simple Network Time Protocol. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193

Power. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193

Shelf Mechanical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194

Shelf Environmental. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194

vi TimeSource 3100 User’s Guide 097-72020-01 Revision K – December 2005

List of Figures

Figures

1-1 TimeSource 3100 Shelf . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

1-2 The GPS Antenna. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

1-3 Block Diagram of the TimeSource 3100. . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

1-4 ESCIU Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

1-5 TimeSource 3100 Passthrough Function . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

2-1 Locating the GPS Antenna. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

2-2 GPS Antenna Location Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

2-3 Sample Rooftop Antenna Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

2-4 Rack Mounting Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

3-1 Antenna-to-Shelf Cabling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

3-2 Installing the Antenna Bracket on a Pipe . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

3-3 Installing the Antenna Bracket on a Post . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

3-4 Attaching the Antenna to the Bracket. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

3-5 Assembling the Lightning Suppressor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

3-6 Location of the Options I/O Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

3-7 Rack Mounting Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

3-8 Connector Panel and Front Panel Connectors. . . . . . . . . . . . . . . . . . . . . . . 54

3-9 Terminal Block Connections on the Connector Panel. . . . . . . . . . . . . . . . . . 55

3-10 E1 or Analog Output Wire-Wrap Connections . . . . . . . . . . . . . . . . . . . . . . . 57

3-11 E1 or Analog Output Wire-Wrap Connections . . . . . . . . . . . . . . . . . . . . . . . 58

3-12 DCD Shelf, Isolation Module, and TimeSource 3100 Connections . . . . . . . 60

3-13 Eight E1 or Analog Output Connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

3-14 Eight Mixed E1/T1 Output Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

3-15 IRIG-B TOD Output Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

3-16 Connector Layout of ESCIU Modules. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

3-17 ESCIU Cutover without Jacks (Out-of-Service) . . . . . . . . . . . . . . . . . . . . . . 65

3-18 ESCIU Cutover with Jacks (In-Service) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

3-19 RS-422 to RS-232 TOD Converter Mounting Plate . . . . . . . . . . . . . . . . . . . 69

3-20 RJ-45 to DB-25 TOD Converter Connections. . . . . . . . . . . . . . . . . . . . . . . . 69

3-21 Alarm Connector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

3-22 The TimeWizard Main Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

3-23 The Download GPS.hex Screen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

3-24 The Load GPS File Dialog Box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

3-25 The Download Progress Dialog Box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

3-26 The Status Information Screen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86

3-27 The Set the Alarm Parameters Screen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

3-28 The View the Alarm Parameters Window. . . . . . . . . . . . . . . . . . . . . . . . . . . 88

3-29 The Exit Application Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

3-30 The Save Log File Dialog Box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

4-1 Command Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

4-2 Completed Response Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

4-3 Deny Response Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

4-4 Alarm Conditioning Flow Chart. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

5-1 Controls and Indicators. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160

5-2 Front of Shelf . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171

6-1 NTP Type 4 Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179

6-2 NTP Type 4 Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180

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List of Figures

viii TimeSource 3100 User’s Guide 097-72020-01 Revision K – December 2005

List of Tables

Tables

1-1 Timing Source Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

2-1 Isolation Kits for DCD Shelves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38

3-1 DCD Connections to the TimeSource 3100 . . . . . . . . . . . . . . . . . . . . . . . . . . .59

3-2 TOD Connector Pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68

3-3 Converter DB-25 Connector Pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69

3-4 Ethernet RJ-45 Connector Pinout. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .70

3-5 COM 1 Connector Pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .70

3-6 COM 1 Connector Pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71

3-7 COM 1 Connector Pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72

3-8 Alarm Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .87

3-9 Parameter Factory Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .90

4-1 Parameter Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .96

4-2 Commands for Tasks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .100

5-1 Front Panel Items . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .161

5-2 Message Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .164

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List of Tables

x TimeSource 3100 User’s Guide 097-72020-01 Revision K – December 2005

How to Use This Guide

This section describes the format, layout, and purpose of this guide.

In This Preface

 Purpose of This Guide  Who Should Read This Guide  Structure of This Guide  Conventions Used in This Guide  Warnings, Cautions, Recommendations, and Notes  Related Documents and Information  Where to Find Answers to Product and Document Questions  What’s New in This Document

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How to Use This Guide

Purpose of This Guide

The TimeSource 3100 User’s Guide describes the procedures for unpacking, installing, using, maintaining, and troubleshooting the Symmetricom TimeSource

3100.

Who Should Read This Guide

Chapter 1, Overview of the TimeSource 3100, and Chapter 2, Engineering & Ordering, are written for non-technical audiences who need general information

about the product. Chapter 3, Installing the TimeSource 3100 and subsequent chapters contain technical information about the product. Other chapters and appendixes describe installation, maintenance, and configuration instructions or details primarily intended for qualified maintenance personnel.

Structure of This Guide

This guide contains the following sections and appendixes:

Chapter, Title Description

Chapter 1, Overview of the TimeSource 3100

Chapter 2, Engineering & Ordering

Chapter 3, Installing the TimeSource 3100

Chapter 4, TL1 Reference

Chapter 5, Troubleshooting Contains preventive and corrective maintenance, and

Chapter 6, Specifications Lists the specifications for the TimeSource 3100 Index Provides references to individual topics within this guide.

Provides an overview of the product, describes the major hardware and software features, and lists the system specifications.

Lists the part number and ordering procedure for all TimeProvider parts and accessories.

Contains procedures for unpacking and installing the product. Includes a list of the factory default values for ha rd wa re and software parameters

Describes TimeProvider after installing the unit.

troubleshooting procedures for the product.

the TL1 commands required to provision the

xii TimeSource 3100 User’s Guide 097-72020-01 Revision K – December 2005

How to Use This Guide

Conventions Used in This Guide

This guide uses the following conventions:

 Acronyms and Abbreviations – Terms are spelled out the first time they appear

in text. Thereafter, only the acronym or abbreviation is used.

 Revision Control – The title page lists the printing date and versions of the

product this guide describes.

 Typographical Conventions – This guide uses the typographical conventions

described in the table below.

When text appears

this way...

TimeSource 3100 User’s Guide

GPS CRITICAL TS3100

Select File, Open... Click the Open option on the File menu. Press

Enter

Press ;

TimeSource Username:

PING STATUS

The title of a document.

An operating mode, alarm state, status, or chassis label.

A named keyboard key. The key name is shown as it appears on the keyboard.

An explanation of the key’s acronym or function immediately follows the first reference to the key, if required.

Text in a source file or a system pro mpt or other text that appears on a screen.

A command you enter at a system prompt or text you enter in response to a program prompt. You must enter commands for case-sensitiv e operating systems exactly as shown.

... it means:

A re-timing application A word or term being emphasized. Symmetricom does not

recommend...

A word or term given special emphasis.

Warnings, Cautions, Recommendations, and Notes

Warnings, Cautions, Recommendations, and Notes attract attention to essential or critical information in this guide. The types of information included in each are explained in the following examples.

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How to Use This Guide

Warning: To avoid serious personal injury or death, do not disregard warnings. All warnings use this symbol. Warnings are installation, operation, or maintenance procedures, practices, or statements, that if not strictly observed, may result in serious personal injury or even death.

Caution: To avoid personal injury, do not disregard caut ion s . All cautions use this symbol. Cautions are installation, operation, or maintenance procedures, practices, conditions, or statements, that if not strictly observed, may result in damage to, or destruction of, the equipment. Cautions are also used to indi cat e a lon g- te rm health hazard.

ESD Caution: To avoid personal injury and electrostatic discharge (ESD) damage to equipment, do not disregard ESD cautions. All ESD cautions use this symbol. ESD cautions are installation, operation, or maintenance procedures, practices, conditions, or statements that if not strictly observed, may result in possible personal injury, electrostatic discharge damage to, or destruction of, static sensitive components of the equipment.

Electrical Shock Caution: To avoid electrical shock and possible personal injury, do not disregard electrical shock cautions. All electrical shock cautions use this symbol. Electrical shock cautions are practices, procedures, or statements, that if not strictly observed, may result in possible personal injury, electr ical shock damage to, or destruction of components of the equipment.

Recommendation: All recommendations use this symbol. Recommendations indicate manufacturer-tested methods or known functionality. Recommendations contain installation, operation, or maintenance procedures, practices, conditions, or statements, that provide important information for optimum performance results.

Note: All notes use this symbol. Notes contain installation, operation, or maintenance procedures, practices, conditions, or statements, that alert you to importa nt information, which may make your task easier or increase your understanding.

xiv TimeSource 3100 User’s Guide 097-72020-01 Revision K – December 2005

How to Use This Guide

Chapter 1 Overview of the TimeSource 3100

This chapter provides an overview of the global positioning system, and a physical and functional description.

In This Chapter

 Overview  Physical Description  Roof Antenna  Functional Description

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Chapter 1 Overview of the TimeSource 3100

Overview

The TimeSource 3100 is a Primary Reference Source (PRS) that receives and processes signals from GPS satellites, and outputs Stratum 1 synchronization signals traceable to UTC. Ti meSource 3100 applications include synchronization for central offices, radio base stations, transmission nodes, and other instances where a primary reference source can improve the performance of telephony network facilities.

The TimeSource 3100 creates timing outputs by ensembling signals from several sources. The sources include GPS signals, an onboard local oscillator , and op tional E1 or analog and remote oscillator signals. Timing outputs created from the ensemble are composed of the most stable and least noisy parts of each input. Synchronization outputs are delivered in a framed, all-ones, E1 or 2.048 MHz analog signal, a 1 pps signal, T1 signals (optional), and time of day (TOD) signals.

The TimeSource 3100 minimizes timing impairments, such as jitter and wander, that are created by network and transmission systems. The synchronization timing is traceable to the GPS, which provides the highest level of synchronization for telephony networks. The TimeSource 3100 with its GPS input is a stand-alone office PRS. With the optional inputs ensembled, overall system performance is improved, and holdover is extended if GPS signals become disrupted.

Global Positioning System

The United States Government developed the GPS navigation system. It is a satellite-based, radio navigation aid designed to provide global, all-weather, precise navigation and timing capability to users 24 hours a day.

The satellites, circling the earth at approximately 20.197 km, are arranged in 6 orbits with 4 operational satellites in each orbit. Each satellite has an orbital period of approximately 12 hours. This configuration assures that a minimum of 4 satellites, and as many as 12, are in view anywhere in the world at all times.

The TimeSource 3100 tracks all satellites wit hin its field o f view . The p erformance of each tracked satellite is observed and compared to th e others, and available for use in the timing solution. A satellite with unacceptable performance data is dropped from the timing solution.

Physical Description

The TimeSource 3100 consists of a shelf, a plug-in card, an antenna, cables, hardware, and software. Optional system configurations include eight additional E1 or analog outputs, two E1 synchronous clock insertion unit (ESCIU) ports, four IRIG-B TOD timing outputs, or eight mixed E1/T1 outputs.

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Chapter 1 Overview of the TimeSource 3100

Physical Description

The shelf (Figure 1-1) can be mounted in a 48 cm rack or an ETSI 53.5 cm rack. Other than a communications connector on the front panel, all connectors are at the connector panel.

Figure 1-1. TimeSource 3100 Shelf

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Chapter 1 Overview of the TimeSource 3100

Roof Antenna

The antenna (Figure 1-2) is encased in weather-resistant plastic housing for outdoor installation, usually on a roof. A single coaxial cable carries signals and power between the antenna and the shelf.

Figure 1-2. The GPS Antenna

Functional Description

Overview

Figure 1-3 shows the main functions of the TimeSource 3100. The center of the

TimeSource 3100 is the Ensemble Timing Generator, which uses the BesTime algorithm to analyze the phase and frequency relationships, individually and collectively, of the timing sources. Each type of timing source has a particular characteristic that gives it an advantage over other sources, as listed in Table 1-1.

The BesTime algorithm uses the best characteristic of each source to produce an output signal with greater overall accuracy and stability than any single source. The contribution of a source is based on its deviation from the weighted average of all the sources. The more accurate a source, the more weight it has in the final output. Every source is under constant evaluation and its contribution subject to periodic adjustment. The output is essentially the best performance of the best source.

20 TimeSource 3100 User’s Guide 097-72020-01 Revision K – December 2005

Table 1-1. Timing Source Characteristics

Source Characteristic

Local Oscillator Short term stability E1 Line Intermediate term stability External Oscillator Intermediate term stability GPS Signal Long term stability

Chapter 1 Overview of the TimeSource 3100

Functional Description

Figure 1-3. Block Diagram of the TimeSource 3100

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Chapter 1 Overview of the TimeSource 3100

Functional Description

Antenna

The antenna housing includes a volute antenna, GPS receiver, amplifier, and intermediate-frequency (IF) downconverter.

The GPS Receiver extracts a clock signal from the GPS satellite signals. The receiver can process the signals from all satellites in view, while simultaneously using the Earth location of the receiver and other factors to determine an accurate clock signal.

An amplifier in the antenna provides 23 dB of signal gain. A downconverter converts the L-band GPS signal to IF for long-distance transport

on the coaxial antenna cable. The antenna cable provides 125 mA power from the shelf to the antenna, and transports GPS satellite IF signals from the antenna to the shelf.

IF Interface

An IF interface accepts the signals from the antenna, and provides the clock information to the BesTime Ensemble Timing Generator.

Local Oscillator

A digitally controlled, oven-controlled crystal oscillator (OCXO) develops a highly stable local oscillator signal, independent of factors that exist outside the shelf. This signal is sent to the BesTime Ensemble Timing Generator.

Clock Extractors

A clock extractor circuit extracts a timing signal from each external reference source (External sources, other than the GPS antenna, are optional). The extracted timing signal is sent to the BesTime Ensemble Timing Generator.

Power Supply

A power converter filters and converts -48 volts dc power supplied to the shelf into the voltages required by the shelf.

NTP TimeServer

The TimeServer is a Simple Network Time Protocol (SNTP) device. The SNTP TimeServer function is provided via the TimeSource Ethernet interface and associated IP address. User software requests UTC time of day via NTP protocol. The TimeSource SNTP server responds with current UTC time. The TimeServer is compatible with the SNTP RFC-1769 format.

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Chapter 1 Overview of the TimeSource 3100

To enable the SNTP feature, a password must be entered using the ED-EQPT TL1 command. If a user makes a fourth attempt of an incorrect password entry, the TimeServer will lock out the user for 1 hour.

Functional Description

Network Time Protocol Password Activation

Use of the Simple Network Time Protocol (SNTP) feature requires activation with a password. Activation is accomplished through receipt of a Network Time Protocol Activation Certificate from Symmetricom. This certificate cont a ins the unit purch ase order number, unit model number, unit activation date, unit serial number, and unit activation key. The unit activation key is the password that enables the SNTP feature. To activate the SNTP feature, enter the TL l command printed on the activation certificate. Once activated, this feature will be permanently enabled. To order the SNTP feature, contact the local Symmetricom sales representative.

BesTime Ensemble Timing Generator

Clock signals from the GPS antenna (via the IF interface), the local oscillator, the optional external sources (E1 span lines and remote oscillators) are used as sources by the BesTime algorithms in the BesTime Ensemble Timing Generator. The signals are analyzed for MTIE, TDEV, and other phase and frequency characteristics.

The BesTime Ensemble Timing Generator uses mathematical models to analyze each clock. The ensemble algorithms use the comparisons and analyses to generate a highly stable timing signal, which uses the best qualities of all inputs.

E1 or Analog Outputs

The BesTime Ensemble Timing Generator provides the timing for the E1 or analog (2.048 MHz) timing signal available at the E1 OUT A and B connectors. E1 is provided in a framed, all-ones format, which can be set to CAS, CAS4, CCS, or CCS4 framing. 2.048 MHz is provided in accordance with G.703/10.

Eight Mixed E1/T1 Outputs (990-72020-06 Systems Only)

This option enables a user to mix any combination of E1 and T1 outputs. A user can also use any combination of framing. For El, CCS, CAS, CCS with CRC4, and CAS with CRC4 can be used per G.703 table 6. For T1, D4 or ESF can be used per ANSI T1.101. In addition, there is support for analog (2.048 MHz) per G.703 table 10 and support for synchronization status messaging (SSM) per TR-33 for El and T1. The module mounts in the OPTIONS I/O mountings on the connector panel.

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Chapter 1 Overview of the TimeSource 3100

Functional Description

Eight Additional E1 Outputs (990-72020-02 Systems Only)

This option provides a module for eight additional E l or analog (2.048 MHz) outputs. The module mounts in the OPTIONS I/O mountings on the connector panel. These outputs function the same as the standard E l outputs.

TOD Output

The BesTime Ensemble Timing Generator provides the timing for the TOD timing signal available at the RJ-45 connector, which provides time code to devices compatible with NTP Type 4 or Cisco format.

IRIG-B TOD Outputs (990-72020-05 Systems Only)

This option provides a module for four additional TOD output s in IRIG-B format. The module mounts in the OPTIONS I/O mountings on the connector panel. The BesTime Ensemble T iming Gene rator provides the timing for the T OD timing signal, which provides timing code to devices compatible with IRIG-B.

1 PPS Output

The BesTime Ensemble Timing Generator provides the timing for the 1 pulse-per-second timing signal available at the 1 PPS connector , which can be used for application-specific requirements.

10 MHz Output

The BesTime Ensemble Timing Generator provides timing for the 10 MHz timing signal available at the 10 MHz connector, which can be used for local cellular frequency or testing purposes.

Two ESCIU Ports (990-72020-04 Systems Only)

This option provides a module for two E1 ports. The module mounts in the OPTIONS I/O mountings on the connector panel. E1 traffic-carrying signals are synchronized using the BesTime Ensemble Timing Generator. Jitter and wander are also removed before sending the E1 signals to network elements.

If an alarm condition or power failure occurs, relays allow the E1 signals to bypass the system (see Figure 1-4).

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Chapter 1 Overview of the TimeSource 3100

Figure 1-4. ESCIU Signals

Functional Description

Alarm Interface

The microprocessor delivers alarms to normally open dry-contact type connections. Alarms are also indicated by the front-panel status lamps.

Communications Ports

Three RS-232 serial communications ports carry TL1 commands, responses, and autonomous messages between the TimeSource 3100 and an external terminal.

Ethernet

TimeSource 3100 has six Ethernet ports to carry TL1 commands, responses, and autonomous messages between the T imeSource 3100 and an external terminal, or an Element Manager. The user can configure the IP address, subnet mask, and gateway address for the Ethernet ports.

Four ports (5001, 5002, 5003, and 5004) are configured to act as though a serial-port communication terminal were connected to them. These ports communicate TL1 commands, responses and autonomous messages.

Two additional ports communicate with Element Managers, which may have NMS, OSMF, or similar software. An Element Manager establishes a connection with one port (5551) for TL1 commands and responses. Another port (5550) establishes a connection to an Element Manager, sends autonomous messages, and closes the connection when finished.

Passthrough

The Passthrough feature of the TimeSource 3100 allows the unit to front a DCD product to provide one management interface for a user site. Passthrough allows a user to do the following:

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Chapter 1 Overview of the TimeSource 3100

Functional Description

 Provide a no download exclusion for the Passthrough port  COM 1 or COM2 is connected to the DCD product  The user port can be any unused port, including the Ethernet port  Messages can pass from a user to the DCD product and from the DCD product

to a user through the TimeSource 3100

 The TID (SID for DCD) is used to identify commands that go to the DCD product.

The TimeSource 3100 passes any TID not its own through to the DCD product. In the reverse direction, all commands received from the DCD product are passed through to the user.

Note: The TID of the TL1 command must be the SID of MIS.

 DCD is fully managed except for firmware download.

Figure 1-5 shows a TimeSource 3100 Passthrough setup.

DCDPASSTHRU

Straight cable

User port (any port)

DCD-5X TS-3100

DCDUSERPORT COM 1, 2, 3 IP:5001-5004

COM 1, 2, or 3

COM1 or 2 (COM-1 is DB-25 and COM-2 is DB-9)

Figure 1-5. TimeSource 3100 Passthrough Function

Alarm Programmability

New releases of TimeSource (1.05.03 and higher) allows the user to provision the alarm escalation parameters that were hardcoded in the previous releases of TS3100.hex. The defaults for this release remain the same as were previously hardcoded. This feature can be used to set the programmability for such alarms as GPS, HOLDOVER, SPAN-X, and RO-X.

The TS3100 alarms can be programmed for GPS and HOLDOVER types of event s. The SPAN-X alarms can be programmed for AIS, ERROR, and LOS types of events. The RO-X alarms can be programmed for ERROR and LOS types of events.

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Functional Description

The user can set the parameters for SEVERITY1 and SERAFF1 which initially come into effect when the condition is detected. The user can also set the parameters for SEVERITY2 and SERAFF2 which come into effect after TIME (another user programmable parameter).

Startup

When the TimeSource starts up, the CRIT lamp lights. The CRIT lamp remains on for approximately 50 seconds to 60 seconds and then shuts off.

During startup, the TimeSource performs several self-tests to verify the integrity of the hardware and software. Neither communication nor outputs are possible at this time, and the CRIT lamp is switched on. Once the self-tests are done, a connection to the system can be made and the events viewed.

Two events are initially provided. These events are:

 “Power Up Restart”  “Settling Period”

In the “Power Up Restart” event, which lasts for approximately 2 minutes, the system does additional checks and starts all the various tasks within the system.

The “Settling Period” event is an informational message that lasts until the TimeSource’s BesTime engine reaches the highest possible stable point. The time taken to reach this point depends on satellite availability, type of oscillator, ambient temperature, etc. and may take up to 20 hours to clear. Since “Settling Period” is independent of the quality of the output and is the normal behavior of the system, it is generated as an event rather than an alarm. If “Settling Period” is not cleared after 24 hours, another “Settling Period” event is generated as a marker. This is still Non-Service-Affecting.

As soon as the “Power Up Restart” message is cleared, the “BT3 Warm-up” event is generated. This is also an informational message that lasts till the time it takes the system to acquire the satellites, warm up the oscillator, and start giving out valid outputs. It may take up to 2 hours for the message to clear, but typically takes approximately 40 minutes. During the “BT3 Warm-up” time, the outputs will generally be squelched. If the outputs are enabled using the TL1 command (ED-EQPT::TS3100:ctag:::ALMCOND=ALW;) they may not be within the PRS mask. In case the system is not able to acquire sufficient number of satellites and/or discipline the oscillator within 2 hours, the event escalates into a Non Service Affecting Minor alarm.

Once the warm up is complete, the system generates valid outputs and the event is cleared.

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Chapter 1 Overview of the TimeSource 3100

Functional Description

Bridging/Holdover Behavior

In the TimeSource 3100, alarms are designed with a built-in hysteresis. This means that an alarm is not announced as soon as some error condition is detected. There is a pre-integration time during which the error must persist in order for the alarm to be announced. On the flip side, the error must be clear for a certain time for an alarm condition to be cleared. This ensures that intermittent conditions are not flagged unnecessarily.

During the normal working of the TimeSource 3100 , it is a very common occu rrence that the GPS satellites may not be visible during certain p a rt s of th e day, depending on the installation of the antenna. This is particularly true with wall and, especially, window antenna installations. The TimeSource 3600 has been designed to work around this situation.

The TimeSource 3100 enters “Bridging” mode when all satellite locks are lost. There is no TL1 annunciation that the system has entered “Bridging” mode. This is “Non Service Affecting” and the outputs are not affected. The system runs off its internal oscillator and the outputs are kept within the G.811 PRS mask by the BesTime engine.

When “Bridging” mode persists for more than 30 minutes, the system enters “Holdover” mode and a “Holdover” event is generated. This may or may not affect the outputs depending on the alarm integration parameters that can be set by the user.

The system allows the user to set various parameters for GPS error , Holdover error, and SPAN error conditions. These parameters are:

 Initial Severity  Initial Service Affecting state  Integration Time  Final Severity  Final Service Affecting state

The system also allows the user to set a parameter to define how outputs should behave in an alarm condition. Outputs can be set to AIS, Squelch, or SSM on an alarm. Outputs can also be set to ignore alarm conditions.

When the “Holdover” event is announced, it is announced with the Initial Severity and Initial Service Affecting state. If the “Holdover” event persists for the length of the Integration Time, the alarm is escalated to the Final Severity and Final Service Affecting state.

The “Holdover” event/alarm is cleared when the satellites are visible again.

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Chapter 1 Overview of the TimeSource 3100

Functional Description

Time Figure of Merit

Time Figure of Merit (TFOM) is a moving 24 hour measurement reported in nanosecond (ns) against an ideal model. TFOM has a frequency component used to measure GPS wander caused by multipath and a time loop component used to measure long term oscillator wander.

The TFOM alarm threshold is set to 500 ns and is not user configurable. A TFOM below 500 ns indicates a stable clock well within PRS output performance specifications. A TFOM between 500 ns and 800 ns is an early warning of a clock becoming unstable and in danger of going out of PRS specification. When the TFOM exceeds 800 ns, the clock is no longer meeting the stratum 1 MTIE mask.

TFOM is most useful for installations where the antenna has a limited view to the sky. This is defined as any installation where fewer than 4 satellites are in view for greater than 1 hour per day on average. This is typical for installations where the antenna is mounted in a window or on an outside wall of a building, but can also include rooftop installations with partial sky view blockage. TFOM’ s primary use is to help troubleshoot multipath issues associated with antenna placement and incorrect latitude, longitude, and/or altitude (location) data entry.

Installations with full view to the sky see 4 satellites 23+ hours a day, seven days a week. It is relatively easy to filter out multipath signals using multiple satellites and simple voting schemes. In addition, rooftop antennas are mounted vertically and all signals below the horizon are obvious multipath interference and can be masked out of the system. With 4 satellites in view, the GPS timing receiver will provide an error-free lock on its location through an automatic survey function.

With wall/window installations, voting schemes become less effective as the number of satellites in view drop. Also, wall/window antennas are mounted horizontally and are prone to seeing multipath signals reflected of f nearby structures and the ground. Wall/window installations also require the manual input of location data, creating the potential for errors and the need to detect these errors.

The TimeSource has unique algorithms to account for, and defeat, the added multipath complications and location data entry error possibilities of wall/window antenna installations. Large amounts of multipath or major errors in location data entry are easier to identify and are detected over a relatively short period of time. These short-term errors are normally reported via the TimeSource tracking success rate parameter.

Small amounts of multipath or minor errors in location data entry are difficult to identify because they mimic a true signal or an expected satellite behavior pattern. Single satellite reception over limited periods of time complicates the ability for the internal TimeSource algorithms to filter out these ghost signals and longer periods of time are needed to sort them out. TFOM tracks and reports these long-term errors.

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Chapter 1 Overview of the TimeSource 3100

Functional Description

At time of installation, marginal or unacceptable TFOM readings can indicate the need to adjust the antenna placement, the mask angle, and/or the location data. Relatively small changes in the antenna placement can improve the ability of the system to see satellites and therefore improve performance. The mask angle can be adjusted to block out lower elevation portions of the sky if there is good visibility at higher elevations, thereby reducing multipath. Correct location data is very helpful in identifying and tracking satellites.

In addition, a clock may be stable for many weeks, months, or years but could degrade because of changes in its environment. TFOM is useful in detecting these infrequent subtle changes including:

 Maturing foliage or seasonal foliage changes  Installation of new transmitters nearby (i.e. wireless base station)  New building construction  Variations in the day-to-day temperature of the CO

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+ 170 hidden pages

Symmetricom TimeSource 3100 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

How to Use This Guide

Chapter 1 Overview of the TimeSource 3100

Overview

Global Positioning System

Physical Description

Roof Antenna

Functional Description

Overview

Antenna

IF Interface

Local Oscillator

Clock Extractors

Power Supply

NTP TimeServer

Network Time Protocol Password Activation

BesTime Ensemble Timing Generator

E1 or Analog Outputs

Eight Mixed E1/T1 Outputs (990-72020-06 Systems Only)

Eight Additional E1 Outputs (990-72020-02 Systems Only)

TOD Output

IRIG-B TOD Outputs (990-72020-05 Systems Only)

1 PPS Output

10 MHz Output

Two ESCIU Ports (990-72020-04 Systems Only)

Alarm Interface

Communications Ports

Ethernet

Passthrough

Alarm Programmability

Startup

Bridging/Holdover Behavior

Time Figure of Merit