Trimble Outdoors AcutimeTM2000 Synchronization Kit guide

F	Theory of Operation

If ephemeris or almanac data is available for the lost satellite, then the satellite's velocity is factored into the center frequency calculation. The diminished accuracy of an older almanac is accounted for in the width of the search range. If neither the ephemeris nor almanac is available, then the Doppler frequency at last lock is searched for two minutes. If the satellite has not been re-acquired after two minutes, then the maximum expected Doppler frequency, based on satellite dynamics, is searched.

If the current position is not accurately known, the search width is increased. If the smart antenna is computing velocity or velocity aiding is provided, then the receiver's motion is also factored into the Doppler frequency. If velocity information is not available, then the dynamics code is used to determine the maximum expected Doppler frequency.

The re-acquisition time for momentary signal blockages is typically under two seconds.

Acutime 2000 Synchronization Kit User Guide

F-9

Image 299

Trimble Outdoors AcutimeTM2000 Synchronization Kit, Part Number 45005-00-ENG manual Theory of Operation

Contents

Acutime 2000 Synchronization Kit Timing and Synchronization Group Software and Firmware License, Limited Warranty Limitation of Liability Contents Acutime 2000 Installation NTP Software Installation and Configuration Trimble Standard Interface Protocol Timing Receiver Monitor Glossary Index List of Figures Page List of Tables List of Tables List of Tables Xvi Acutime 2000 Synchronization Kit User Guide Acutime 2000 Synchronization Kit User Guide Xvii Page Scope and Audience About This Manual Organization Reader Feedback World Wide Web WWW Site Update NotesRelated Information Technical Assistance AbbreviationsDocument Conventions Page Overview Introduction Acutime 2000 GPS Smart Antenna Features Acutime 2000 GPS Smart Antenna Enclosure Starter Kit Getting Started Connecting the Smart Antenna Connection Diagram Connecting the Computer and Power Source Communicating with the Acutime Acutime 2000 Installation Mounted Antenna Choosing a Location Acutime 2000 Installation Mounting the Smart Antenna Routing and Securing the Interface Cable Connecting the Host System Acutime 2000 Connections Acutime 2000 Interface Connector Interface and Power Connections Acutime 2000 12-pin Connector format Antenna Mating Manufacturer Description Connector Interface Cables and ConnectorsMating Connectors Acutime 2000 RS-422 Cable Pin-Out Signal Description Wire Color Protocol Acutime ConnectorPin-Outs Acutime 2000 RS-232 Cable Pin-Out Timing Pulse Connections Power Connection Red and Black WiresConnection Instructions Port B Serial Port Connections Port a Event InputPage Start-Up System Operation Satellite Masks Default Satellite Mask SettingsMask Setting Automatic Operation Pdop Mask SNR Mask Tracking Modes Self-Survey Mode Overdetermined Clock Mode PPS Output Options PPS Quantization Error PPS Quantization Error Removing the Quantization Error from the PPS Output External Event Input Cable Delay Compensation Port a Timing Serial Data CommunicationPort B System Operation GPS Timing Timing Operation Timing Pulse Output PPS Using the Acutime 2000 in Mobile Applications Customizing Acutime 2000 Operations Parameter Factory default Set Request Report Receiver Configuration segmentOEM Configuration segment Position Information segment Port a and B Configuration segmentPPS Configuration segment UTC Information segment Nmea Configuration segmentParameter Factory default Set Request Report Haveutc System Operation Acutime 2000 Synchronization Kit User Guide Network Time Protocol NTP Software Installation and Configuration NTP Time Server Requirements NTP Time Servers Software Sources and Compatibility Installation Support Pre-Installation Check List GPS Preparation Host System Preparation Operating System Specific Information Time Transfer Cable Connection Time Transfer Connection Diagram Optional Connections NTP Software Installation NTP Configuration File NTP Configuration File Unit Number Acutime Configuration Network Server Selection Additional Configuration Information Windows NT Installation Automatic Installation Create the Configuration File Manual Installation NTP Software Installation and Configuration Copying Executable Files Copy NTPQ.EXE, NTPDATE.EXE, NTPDC.EXE, NTPTRACE.EXE Type instsrv c\winnt\system32\ntpd.exe Installing the ServicePage Starting the Service Unix Installation Create the Configuration File Cd /dev Ln -s ttyS0 /dev/Acutime0 Set Up Device Links Hpux System Serial Ports and Symbolic Link Names Disabling Serial Port Services Using an Administrative Tool Hardware Configuration Copying Executable Files System Initialization Start NTP Monitoring NTP Event Log Entries NTP Events on Windows NT NTP Software Installation and Configuration Sample Unix Log Entries Unix System Log Files Ntpq The NTP Query Utility Acutime NTP reference clock is identified in the list as NTP is Communicating with the Acutime NTP Reference Clock No Response from the Acutime NTP Reference Clock NTP is not Running NTP Software Installation and Configuration Interface Scope Trimble Standard Interface Protocol Packet Structure Physical Interface Characteristics Table A-2 NomenclatureProtocol Capabilities Table A-1 Ace UTC Port Translation Table Event Input Primary Port FeaturesSecondary Port Features Acutime Table A-3 Secondary Port Features Acutime Event Reporting Table A-5 Event Packets Packets Output at Power-UpSecondary Port Features Ace UTC Table A-4 Secondary Port Features Ace UTC Output ID Description Table A-6 Packets Output at Power-UpTable A-7 Receiver Warm Start Commands Receiver Warm Start Table A-8 Background Packets Default Background Packets for Acutime Table A-9 Automatic position and Velocity Reports Default Automatic Position and Velocity Reports for Acutime Lltp Packet ID Description Request Packet ID Low-Latency Timing PacketsTable A-10 Low-Latency Timing Packets Input ID Description Output ID Event PacketsSatellite Data Packets Table A-11 Satellite Data Packets Table A-12 Customizing Receiver Operations Customizing Receiver Operations Table A-13 Advanced Packets Input Packet Description Output ID Command Packets Sent to the ReceiverTable A-14 Command Packets Sent to the Receiver 8E-AB Output ID Packet Description Input Report Packets Sent by the GPS Receiver to the UserTable A-15 Report Packets Sent by GPS Receiver to User ATrimble Standard Interface Protocol 8F-AD DLE id data string bytes DLE ETX Packet Structure Oscillator Offset Table A-16 Command Packet 1D Clear Oscillator OffsetTable A-17 Command Packet 1D Set Oscillator Offset Packet Descriptions 0x1F Command Packet 1F Initiate Cold or Factory ResetTable A-18 Command Packet 1E 0x1E Command Packet 1E Almanac Request Initial Position XYZ Cartesian Ecef CommandTable A-19 Command Packet 0x20 0x21 0x23 Health Request GPS Receiver Position Fix Mode RequestInitiate Soft Reset / Self Test Command 0x24 0x25 GPS System Message Request Signal Levels RequestAltitude for 2-D Mode Command 0x27 0x28 0x29 0x2A Trimble Standard Interface Protocol Oscillator Offset Request Initial Position Latitude, Longitude, Altitude CommandTable A-20 Command Packet 2B 0x2B 0x2D 0x2E 0x2F 0x31 GPS Time CommandAccurate Initial Position XYZ Cartesian Ecef Command Table A-21 Command Packet 2E Trimble Standard Interface Protocol 0x32 0x34 Satellite Number For One-Satellite Mode Command 0x35 Command Packet Option Flags Command Table A-22 Command Packet Byte Bytes Trimble Standard Interface Protocol Byte Download and UpLoad Satellite System Data 0x37 0x38Last Position and Velocity Request Byte Type Value Meaning Table A-23 Command Packet 0x39 Command Packet Satellite Attribute Database CommandTable A-24 Command Packet Satellite Ephemeris Status Request Table A-25 Command Packet 3ATable A-26 Command Packet 3B Last Raw Measurement Request Satellite Tracking Status Request Table A-27 Command Packet 3C0x3C Command Packet 3C Almanac Data Page Report Timing Port Configuration CommandEeprom Segment Commands Table A-28 Command Packet 3F-11 Report Packet 0x41GPS Time Report Table A-30 Report Packet Status Code Table A-31 Relationship Between Packet 41 and PacketApproximate Time Time Source Sign Packet Accuracy 0x42 Report Packet Single-Precision Position Fix, XYZ Ecef ReportTable A-32 Report Packet 0x43 Report Packet Velocity Fix, XYZ Ecef ReportTable A-33 Report Packet Byte Type Software Version Information ReportTable A-34 Report Packet 0x45 Report Packet 0x46 Report Packet Health of Receiver ReportTable A-35 Report Packet Table A-36 Report Packet Error Code Meaning if bit value = Bit Position Table A-37 Report Packet Signal Levels for all Satellites Report0x47 0x48 GPS System Message Report Table A-39 Report Packet 4A Report Reference Altitude 0x49 0x4AAlmanac Health Page Report Table A-38 Report Packet Latitude Table A-42 Byte 1 Bit Encoding Status Machine/Code ID and Additional Status ReportTable A-41 Report Packet 4B 0x4C Report Packet 4C Byte Type, Units Default Value, VelocityOperating Parameters Report Table A-43 Report Packet 4C Table A-44 Report Packet 4E 0x4D 0x4EGPS Time Change Acknowledgment Byte Value Type UTC Parameters ReportTable A-45 Report UTC Parameters 0x4F Report Packet 4F 0x54 Report Packet Bias and Bias Rate ReportOption Flags Report Table A-46 Report Packet 0x56 Report Packet Velocity Fix, East-North-Up ENU ReportTable A-47 0x56 Velocity Fix, East-North-Up ENU Report Byte Type/Units Value Information About Last Computed Fix ReportTable A-48 Report Packet 0x57 Report Packet 0x58 Report Packet Satellite System Data/Acknowledge from ReceiverTable A-49 Report Packet Byte Type Meaning Table A-50 Report Packet 58 Almanac Data Report Table A-52 Report Packet 58 Ionosphere Data Report Table A-51 Report Packet 58 Almanac Health Data Report Table A-54 Report Packet 58 Ephemeris Data Report Table A-53 Report Packet 58 UTC Data Report Iode Byte 0x59 Report Packet Satellite Attributes Database ReportTable A-55 Report Packet Report Packet 5A 0x5ARaw Measurement Data Report Table A-56 Report Packet 5A Doppler Signal levelCodephase 0x5B Report Packet 5B Satellite Ephemeris Status ReportTime of measurement Table A-57 Report Packet 5B Byte/Item Type/Units Value/Meaning Satellite Tracking Status ReportTable A-58 Report Packet 5C 0x5C Report Packet 5C Approximate elevation of this satellite Report Packet 5F-11 0x5F-11Eeprom Segment Status Reports Table A-59 Report Packet 5F-11 Eeprom Segment Status Report Byte Bit Type Range Units 0x60 Command PacketType 1 Differential GPS Corrections Table A-60 Report Packet 0x60 Data Formats SV PRN Byte Bit Type Value Definition Set Differential GPS Corrections Table A-62 Command Packet 0x61 Data Formats0x61 Command Packet 0x6D Report Packet 6D All-In-View Satellite Selection ReportTable A-63 Report Packet 6D Set or Request Nmea Interval and Message Mask Table A-64 Command Packet 7A0x7A Command Packet 7A Table A-65 Report Packet 0x7B 0x83Nmea Message Output Double-precision XYZ Position Fix And Bias Information 0x84 Report Packet Double-precision LLA Position Fix and Bias InformationTable A-66 Report Packet Survey State Active Configuration Set Primary Receiver ConfigurationTable A-67 Survey State Configurations 0xBB Command Packet BB Dynamics Code Table A-68 Vaild GPS Configuration Settings Signal Level Mask Byte # Type Value Meaning Default Table A-69 Pdop Mask and SwitchCommand Packet BB Table A-69 Command Packet BB 0xBC Command Packet BC Report Receiver ConfigurationSet Port Configuration Parameters Table A-70 Command Packet BC 0xBC Report Packet BC Request Port Configuration Parameters Tsip Superpackets Custom OEM Packets 0x8E-0B Request or Configure Super Packet OutputCommand Packet 8E-0B Set New Datum Table A-71 Command Packet 8E-14Command Packet 8E-14 0x8E-14 Request Current Datum Values Table A-72 Command Packet 8E-14Command Packet 8E-15 0x8E-15 0x8E-41 0x8E-200x8E-26 0x8E-45 Revert Segments to Default SettingsTable A-74 Command Packet 0x8E-45 0x8E-42 0x8E-4A Set/Request PPS CharacteristicsTable A-75 Command Packet 8E-4A Command Packet 8E-4A Automatic Packet Output Mask Table A-76 Command Packet 8E-4DCommand Packet 8E-4D 0x8E-4D Bit # Output Default When Meaning Packets Table A-77 Command Packet 8E-4D Packets Affected By Bits Set PPS Output Option Command Packet 8E-4E0x8E-4E Set or Request Packet Broadcast Mask 0x8E-4F0x8E-A5 Set PPS Width Trimble Standard Interface Protocol Byte Bit Type Default Description Table A-80 Command Packet 8E-A5 Set Self-Survey Parameters Issue Self-Survey Command0x8E-A6 0x8E-A9 Byte Type Value Description Command Packet 8E-A9 Data Format segmentTable A-82 Request Primary Timing Packet Table A-83 Command Packet 8E-ABCommand Packet 8E-AB 0x8E-AB Request Supplemental Timing Packet Table A-84 Command Packet 8E-ACCommand Packet 8E-AC 0x8E-AC 0x8E-AD Command Packet 8E-AD Acutime 2000 only Report Packet 8F-0B 0x8F-0BComprehensive Time Table A-85 Report Packet 8F-0B 38-41 Oscillator Drift Report Packet 8F-14 0x8F-14Current Datum Values Table A-86 Report Packet 8F-14 Report Packet 8F-20 00x8F-20Last Fix with Extra Information binary fixed point Table A-87 Report Packet 8F-20 Bytes Item/Type Meaning 32-47 Table A-88 Report Packet 8F-20 Report Packet 0x8F-26 0x8F-26Response to Save Eeprom Segments Table A-89 Report Packet 0x8F-26 Report Packet 8F-41 0x8F-41Manufacturing Parameters Table A-90 Report Packet 8F-41 Report Packet 8F-42 0x8F-420x8F-45 Table A-91 Report Packet 8F-42 Byte # Type Value Default Meaning Table A-92 Command Packet 8E-ADCommand Packet 8E-AD Request 8F-AD Report Packet 8F-4A PPS Characteristics0x8F-4A Table A-93 Report Packet 8F-4A Table A-95 Report Packet 8F-4D Bit # Output When Output Meaning Packets0x8F-4D Table A-94 Report Packet 8F-4D Report Packet 8F-A5 0x8F-4E0x8F-A5 Report Packet 0x8F-4E 0x8F-AB 0x8F-A60x8F-A9 116 Acutime 2000 Synchronization Kit User Guide UTC Integer Table A-96 Report Packet 0x8F-AB Report Packet 8F-AC 0x8F-AC Acutime 2000 Synchronization Kit User Guide 119 120 Acutime 2000 Synchronization Kit User Guide GPS Byte Table A-97 Report Packet 8F-AC Reserved 16-19 Bias Report Packet 8F-AD 0x8F-ADPrimary UTC Time Table A-98 Report Packet 8F-AD Flag Value Status Meaning Table A-99 Tracking Status Flag Definitions Bit # Name Meaning if set to Table A-100 Leap Second Flag DefinitionsLeap Second Flag Index Axis Eccentricity Description DatumsTable A-101 Datums Acutime 2000 Synchronization Kit User Guide 127 128 Acutime 2000 Synchronization Kit User Guide Acutime 2000 Synchronization Kit User Guide 129 130 Acutime 2000 Synchronization Kit User Guide Acutime 2000 Synchronization Kit User Guide 131 132 Acutime 2000 Synchronization Kit User Guide Acutime 2000 Synchronization Kit User Guide 133 Sample Tsip Routines Sending out Tsip command packet 0x1F Acutime 2000 Synchronization Kit User Guide 135 Handling incoming Tsip packet Acutime 2000 Synchronization Kit User Guide 137 Page Timing Receiver Monitor Main screen Nmea Nmea 0183 Message Format Table C-1 Nmea 0183 CharacteristicsSignal Characteristic Nmea Standard Nmea 0183 Communication Interface Each message contains multiple data fields Dn Table C-2 Acutime 2000 Nmea Messages Setting Message DescriptionNmea 0183 Message Options Field Description Nmea 0183 Message FormatsGGA GPS Fix Data Table C-3 GGA GPS Fix Data Message Parameters Field # Description GLL Geographic Position Latitude/Longitude GSA GPS DOP and Active Satellites Table C-6 GSV GPS Satellites in View Message Parameters GSV GPS Satellites in View RMC Recommended Minimum Specific GPS/Transit Data VTG Track Made Good and Ground Speed Table C-9 ZDA Time & Date Message Parameters ZDA Time & Date Nmea Acutime 2000 Synchronization Kit User Guide Weight Acutime 2000 GPS Smart Antenna SpecificationsTable D-1 Physical Specifications Dimensions Table D-3 Performance Specifications Table D-2 Environmental Specifications Table D-4 Electrical Specifications Table D-5 Serial Protocols Port Interface Protocols Defaults Acutime 2000 Standard Interface Cable Diagram Figure D-1 Acutime 2000 Standard Interface Cable Figure D-2 NTP Interface Cable Specifications and Drawings System Log Entries Diagnostics and Debugging Serial Port Acces Report Configuration File Not Found Error Log Entries Acutime 2000 Synchronization Kit User Guide Acutime Configuration Failure COM Port Unavailable System Clock Not Set Running NTP in Debug Mode NTP Startup and Acutime Poll Debug Mode Not Available NTP Diagnostics and Debugging Acutime is not Responding Possible Problem Solution Running NTP with Event Polling DisabledTable E-1 Troubleshooting Acutime is Not Responding Fudge 127.127.127.x flag2 Palisadepoll unit x polling synchronous packet Incorrect Port and Bad Data Table E-2 Troubleshooting Incorrect Port and Bad Data Serial Port is Unavailable Compiling the NTP Distribution NTP Diagnostics and Debugging NTP Diagnostics and Debugging NTP Diagnostics and Debugging Controlling the NTP Service Removing the NTP Service Windows NT Administration Type instsrv remove Additional Information Page Theory of Operation GPS Satellite Message Cold Start Satellite Acquisition and Time to First Fix Warm Start Hot Start Garage Search Strategy Selective Availability S/A Position Accuracy Nmea Coordinate SystemsTsip Re-Acquisition Performance CharacteristicsUpdate Rate Dynamic Limits Theory of Operation Figure F-2 System Architecture Figure F-1 Acutime 2000 Block Diagram RS-232 Version Page Glossary Ascii DCE DOP Elevation mask Gdop GPS Iode Pdop ROM SEP SPS Index Index-2 Acutime 2000 Synchronization Kit User Guide Index-3 Index-4 Acutime 2000 Synchronization Kit User Guide Reader Comment Form