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M e r i d i a n   I I   U s e r   M a n u a l

73

"Smarter Timing Solutions"

Chapter 

Seven

Network Time Protocol (NTP)

This chapter describes how to configure the Meridian II Precision TimeBase as an NTP Server.  It 

also includes brief instruction for setting up NTP Clients on your Unix-like or Windows platform.  

This manual is not a ‘How-To’ on installing and using NTP.  Only basic approaches to NTP client 

configuration for operation with Meridian II will be described.   If you have never used NTP, then you 

should spend some time reading the on-line documents, especially the Distribution Notes, FAQ and 

Configuration subject matter, which are available at:    

 

http://www.ntp.org

A simple introduction to NTP is here:

 

http://www.endruntechnologies.com/pdf/NTP-Intro.pdf

 

 

Configuring the 

 

NTP Server

Configuring the Meridian II as a Stratum 1 Server

To configure your Meridian II as a Stratum 1 NTP Server you must have successfully completed 

the Basic Installation procedures in Chapter 2.  By default, Meridian II is configured to respond to 

NTP requests from clients that may or may not be using MD5 authentication.  If the clients are using 

MD5 authentication, they must be configured properly with the same MD5 authentication keys as 

Meridian II.  If you need to modify the factory default Meridian II MD5 keys (recommended) or set 

up broadcast/multicast operation, then you will need to reconfigure the NTP subsystem.  You may 

perform the configuration from either a

 telnet

 or 

ssh

 session, the front-panel keypad, or the local 

RS-232 console.

NOTE

If you would like to configure your server for multicast operation, configure it as you would for broadcast 
operation, with the exception that you must enter this specific NTP IPV4 multicast address: 224.0.1.1, or 
this specific IPV6 multicast address ff05::101, when you are prompted to enter the broadcast address.

  

Configuring NTP Using the Front-Panel Keypad/Display

To configure NTP using the front-panel keypad go to the Main Menu display.  Press the RIGHT ar-

row key until the “NTP” selection is highlighted.  Press ENTER again.  Press the RIGHT arrow key 

to highlight “Setup” and press ENTER.  From this display you can configure broadcast/multicast 

mode.  You can also select previously configured MD5 authentication keys from this display.  How-

ever, to configure new keys you will need to run 

ntpconfig

 (see below).

Summary of Contents for Meridian II

Page 1: ...Smarter Timing Solutions USM3043 0000 000 Revision 8 April 2019 Meridian II Precision TimeBase GPS Synchronized User Manual...

Page 2: ......

Page 3: ...o fulfill the demanding needs of the time and frequency community since 1998 The instruments produced by EndRun Technologies have been selected as the time and frequency reference for such rigorous ap...

Page 4: ...Technologies will repair or replace at its option products which prove to be defective For warranty service or repair this product must be returned to EndRun Technologies Buyer shall prepay shipping...

Page 5: ...her circumstances arise that require more than 5 days an EndRun service technician will contact you Loaner units are not included as part of the standard warranty Repair After Warranty Expiration If t...

Page 6: ...y iii Chapter One Introduction 1 Main Features 1 Robust GPS Receiver 1 Highly Reliable Modular Design 1 Standard Features 2 Secure Network Interface 2 Free FLASH Upgrades 2 Time Synchronization Compon...

Page 7: ...tion 15 Using Telnet 16 Using SSH 16 Using HTTPS 17 Connecting Instruments to the Meridian II 17 Chapter Three Console Port Control and Status 19 Console Ports 19 General Linux Operation 19 Available...

Page 8: ...utkp 33 logrinex 33 netconfig 34 ntpconfig 34 ntpstat 34 oscctrlstat 35 passwd 36 pluginopts 36 pluginoptsconfig 37 ptpconfig0 and ptpconfig1 Optional 37 ptpstat0 and ptpstat1 Optional 37 pwrfltmask O...

Page 9: ...memodeconfig 43 sysversion 43 tfomfltlvl 43 triggerppo Optional 43 unlockkp 43 updatekernelflag 44 updaterootflag 44 upgradekernel 44 upgradercvr 44 upgradercvrfpga 45 upgraderootfs 45 upgradesubsys 4...

Page 10: ...TP Page 56 PTP Status and Configuration Pages Optional 57 Firmware Firmware Status Page 57 Firmware Linux RFS Upgrade Page 57 Firmware Linux Kernel Upgrade 58 Firmware GPS Subsystem Upgrade Page 58 Fi...

Page 11: ...ations and Informs 69 Configuration of SNMPv3 70 Disable or Restrict Access 71 Chapter Seven Network Time Protocol NTP 73 Configuring the NTP Server 73 Configuring the Meridian II as a Stratum 1 Serve...

Page 12: ...lient for Broadcast 85 Configure NTP Client for Multicast 86 Test Broadcast Multicast 86 Chapter Eight IPv6 Information 89 IPv6 Capabilities 89 OpenSSH 89 Apache HTTP 89 Net SNMP 89 NTP 90 IPv4 Only P...

Page 13: ...101 Change the Time Code Format 101 CPU Module Options 101 Programmable Pulse Output PPO Option 102 View and Change the PPO 102 Trigger PPO Function 103 Direct Digital Synthesizer DDS Option 104 View...

Page 14: ...15 Low Phase Noise LPN Module 115 Sine Wave Module 116 Direct Digital Synthesizer DDS Sine Wave Module 116 Telecom Clock Module 117 User Settings 118 Alarms 120 Connectors and Cables 121 5071A Cesium...

Page 15: ...Panel Keypad and Display 137 Display Description 137 Keypad Description 137 Display and Keypad Operation 138 Traversing the Display Structure 138 Editing 138 Keypad EDIT Lockout 139 Using Help 139 Sh...

Page 16: ...Menu CPU_I O 145 Network Menu 145 Network Network4 145 Network Network6 145 Network MAC Address MAC_Addr 145 Network REBOOT 146 NTP Menu 146 NTP Status 146 NTP I O Statistics I O_Stats 146 NTP Setup 1...

Page 17: ...9 Performing the GPS Receiver FPGA Upgrade 159 Appendix C Helpful Linux Information 161 Linux Users 161 Linux Commands 161 Detailed Information Is Available 161 Change Password 162 List Active Process...

Page 18: ...ght 179 Appendix F Leap Seconds 183 Automatic Leap Second Insertion 183 Background Information 183 Appendix G System Faults 185 Overview 185 Masking Faults 185 System Fault Definitions 185 Receiver Fa...

Page 19: ...nsole Port Commands 193 clearalmanac 193 resetlastgpswn 194 resetleaphistory 194 Appendix K Specifications 197 System Oscillator 201 Power Supply Options 203 Software Options 203 CPU Module Options 20...

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Page 21: ...sciplined to match the frequency of the UTC timescale to less than 1 part in 1013 over 24 hour observation intervals The time and frequency outputs are coherent after initial GPS synchronization and m...

Page 22: ...cluding NTP SNMP with Enterprise MIB SSH Telnet FTP HTTPS and SNTP Refer to Chapter 2 Basic Installation for information to help you set up your network interface The inclusion of SNMP v3 and SSH prov...

Page 23: ...emble of high performance cesium beam and rubidium vapor atomic frequency standards located in the monitoring stations and satellites GPS time is measured relative to UTC as maintained by the United S...

Page 24: ...install an antenna with good sky vis ibility preferably on the rooftop Client Slave Software Meridian II has been designed to operate in conjunction with existing public domain NTP SNTP cli ent softw...

Page 25: ...ike operating systems would be helpful it is not essen tial If you satisfy these conditions the instructions provided herein should guide you to a successful installation For a brief description of so...

Page 26: ...onnectors GPS Antenna Input This TNC connector mates with the downlead cable from the external antenna RS 232 Port This DB9M connector provides the RS 232 serial I O console interface to the Meridian...

Page 27: ...and is usually not installed If installed see description in Chapter 10 Rear Panel I O and signal definition in Appendix K Specifications Digital Code Output This BNC connector provides the optional d...

Page 28: ...minal block provides connection to the Option DC power source and replaces the AC power input jack See details in Chapter 10 Rear Panel I O and Appendix K Specifications Dual Power Supplies This optio...

Page 29: ...the chassis and antenna in their desired locations If you are unable to achieve GPS lock after 24 hours then contact EndRun Customer Support for assistance Installing the Meridian II FCC NOTICE This...

Page 30: ...an II will attempt to configure the Ethernet interfaces automatically via the Dynamic Host Configuration Protocol DHCP The Meridian II will attempt to set the netmask its IP address the IP address of...

Page 31: ...VT100 compatible terminal or a terminal emulation program running on your computer We will refer to either of these as termi nal for the remainder of this instruction 1 Disconnect power from the Meri...

Page 32: ...d informational messages is displayed as the kernel begins execution and the various device drivers are initialized When the boot process completes the Meridian II login prompt is displayed Welcome to...

Page 33: ...TE If you want to use the HTTPS Interface then be sure to configure the name server IP address during the netconfig process The HTTPS Interface will not operate properly if this is configured incorrec...

Page 34: ...your DHCP server to determine the expected IP address and log in to the Meridian II using telnet or ssh to verify successful DHCP configuration Refer to the subsequent topics in this section Using Te...

Page 35: ...r s for your network you may check that by issuing this com mand Meridian II GPS root Meridian II cat etc resolv conf search your domain nameserver 192 168 1 1 nameserver 192 168 1 2 Which displays th...

Page 36: ...an 19 14 17 44 UTC 2013 Meridian II GPS root Meridian II This last line is the standard Meridian II prompt After configuring the unit you should change the passwords using the Linux passwd command iss...

Page 37: ...anced CMOS ACMOS drivers which are able to maintain output TTL levels into a 50 ohm load The optional low phase noise spectrally pure sine wave outputs are capable of driving 1 Vrms into a 50 ohm load...

Page 38: ...M e r i d i a n I I U s e r M a n u a l 18 C H A P T E R T W O Refer to Chapter 10 Rear Panel I O and to Appendix K Specifications for more information on the rear panel output signals...

Page 39: ...l Linux Information Console Ports Three interface ports are available on Meridian II Two are 10 100 1000Base T Ethernet ports and one is an RS 232 serial port Network cables and a serial cable are pro...

Page 40: ...the current GPS almanac data for all satellites in Yuma format dumpephemeris Prints the last received GPS ephemeris data for all satellites in Rinex 3 01 format faultstat Prints the summary of all sys...

Page 41: ...nd to lock out access to the front panel keypad EDIT key See the kplockstat and unlockkp commands logrinex Controls logging of raw GPS pseudorange and carrier phase observations in Rinex 2 11 format n...

Page 42: ...Prints the serial number of the Meridian II setantfltmask Command to enable or mask the Antenna Fault See the antfltmask command setcaldelay An interactive utility that allows you to change the clock...

Page 43: ...ystimemodeconfig Interactive utility that guides you in configuring the time mode settings for the front panel display the Time Code Output or the optional Serial Time Output Allows setting to the LOC...

Page 44: ...II after running this script for the changes to take effect Command accessconfig Meridian II reply Interactive script is started antfltmask This command displays the current setting for the Antenna Fa...

Page 45: ...pt is started cpustat This command shows a group of key values for monitoring the health of the Linux CPU and operat ing system status The format is YYYYMMDD HH MM SS LLL FREEkB TT TC Where YYYY is th...

Page 46: ...5364822960e 03 3 31200000000e 05 1 26659870148e 07 1 15738910133e 00 5 58793544769e 09 9 63788168503e 01 2 12843750000e 02 4 50864037440e 01 7 82032574796e 09 3 27513642258e 10 1 00000000000e 00 1 890...

Page 47: ...ellite operation is possible once an initial accurate position has been determined When the dynamic mode is ON only a very minimal TRAIM algorithm is in effect because the ac curate reference position...

Page 48: ...of GPS fixes is displayed first The WGS 84 latitude and longitude in degrees minutes seconds format and the height above the WGS 84 reference ellipsoid in meters follow Also the current RMS PDOP of th...

Page 49: ...al Processor State one of 0 Acquiring 1 GPS Locking 2 GPS Locked 9 Warming Up NN is the number of GPS satellites being tracked 0 to 12 AGC is the RF front end Automatic Gain Control 8 bit DAC value Ty...

Page 50: ...bsystem Communication GPS Reference Time GPS Receiver Communication Char 2 GPS Antenna System Osc PLL Secondary Power Supply Primary Power Supply Char 3 System Power Configuration N A 5071A Plug in Op...

Page 51: ...rs on either June 30 or December 31 The second line of output contains the parameters for calculating the small residual offset between the GPS master clock ensemble and UTC USNO This is typically les...

Page 52: ...ile which is non volatilely stored in the FLASH disk boot etc directory You must reboot Meridian II after running this script for the changes to take effect Command inetdconfig MeridianII reply Intera...

Page 53: ...logging is not currently in progress then a new log of 2880 observations taken every 30 seconds will begin Assuming full constellation visibility this will take 24 hours to com plete If a previously i...

Page 54: ...to configure the NTP Subsystem of Merid ian II By default the unit is configured to authenticate its replies to clients using its default MD5 keys in the etc ntp keys file If you need to create your...

Page 55: ...after 4 294 967 295 packets Below is an example of a typical response to this command Command ntpstat MeridianII reply 20130117 00 02 40 0 000000051 129127988 129015079 1594 4 sec 15 oscctrlstat This...

Page 56: ...he maximum or minimum will set the DAC fault flag that will appear in the fault status display The Time Status display will also indicate a fault condition TEMP is the chassis internal temperature in...

Page 57: ...available if the Precision Time Protocol PTP option has been installed Refer to Chapter 9 PTP IEEE 1588 for more information pwrfltmask Optional See Chapter 10 Rear Panel I O Masking Dual Power Supply...

Page 58: ...om creating an alarm condition Some installations may need to mask this fault due to special antenna situations like splitters or DC blocks that confuse the antenna detection circuit The factory defau...

Page 59: ...o setting a new reference position you can also invalidate an existing one We recom mend you do this if Meridian II has an established position and then you move your GPS antenna You can invalidate an...

Page 60: ...e time error will produce a signal loss fault which then creates an alarm condition The factory default setting is 9 which is the maximum TFOM value Command settfomfltlvl 6 MeridianII reply TFOM Fault...

Page 61: ...t parses and formats the data contained therein and prints this fixed length generally since grossly unsynchronized states could cause the floating offset field to overflow mo mentarily string having...

Page 62: ...the Time Code Output the Direct Digital Synthesizer DDS Output and the Serial Time Output See Chapter 10 Rear Panel I O for information on the various options Command systemio MeridianII reply System...

Page 63: ...volatile Command systimemodeconfig MeridianII reply Interactive utility is started sysversion This command displays the firmware version and build date of the Linux root file system Command sysversion...

Page 64: ...e FACTORY root file system partition Refer to Appendix B Upgrading the Firmware for detailed instructions for performing the upgrade procedure One argument is accepted whose value is either 0 or 1 whi...

Page 65: ...has been copied to the tmp directory on the system It performs an erase of the upgrade root file system partition and then writes the tmp rootfs gz file to it Refer to Appendix B Upgrading the Firm w...

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Page 67: ...on in Meridian II uses HTTP over SSL SSL is a sublayer under standard HTTP HTTPS enhances security because it encrypts and decrypts the requested and returned pages from the server including any passw...

Page 68: ...n your web browser must be configured to allow pop up windows To get started with the web interface simply point your browser to the IP address of Meridian II and log in securely with HTTPS Following...

Page 69: ...the page below the main menu tabs are Home Receiver Plots Clock I O Faults Network NTP PTP and Firmware The tabs across the top and the left side links are logically ar ranged for easy navigation Pag...

Page 70: ...and Display Configuration Hour Display This field defines whether the front panel display shows time in 12 hours Mode AM PM or 24 hours It can only be changed via the front panel keypad display Navig...

Page 71: ...ot shown on any of the plot pages is the last data plot viewed This could be from any one of the data types CPU Receiver NTP Oscillator Ionosphere All plot files are kept in directories There is one d...

Page 72: ...l value is 150 to 200 in good signal conditions Average C No The carrier to noise ratio is an indicator of the GPS signal quality This number typically ranges from 39 to 50 dB when Meridian II is lock...

Page 73: ...fields show the parameters for calculating the small residual offset WNt tot between the GPS master clock ensemble and UTC USNO This is typically less than 10 nanoseconds Current This is the current...

Page 74: ...per day Ageing Rate several hours delay before the first measurements are displayed Control Loop TAU This field shows the system oscillator control loop averaging time constant in seconds It s value...

Page 75: ...change the settings of the CPU Module outputs See Chapter 10 Rear Panel I O for information on the various options I O Page Plug In Options This page shows any installed Plug In Modules and their sett...

Page 76: ...re itself using the Dynamic Host Configuration Protocol DHCP If you need to set up static IP configuration you must use the netconfig command via the console port Thie field will show whether DHCP is...

Page 77: ...ics accumulated since the last reboot of the system Packets Sent Received Packets Sent Rate Packets Dropped PTP Status and Configuration Pages Optional The fields on these pages show the status and th...

Page 78: ...how to perform the upgrade either via the network port the serial port or the HTTPS interface see Appendix B Upgrading The Firmware Firmware GPS Receiver Upgrade Page This page is used for upgrading t...

Page 79: ...ure user authentication and session privacy In addition the Network Time Proto col daemon ntpd supports client server authentication security measures to deter spoofing of NTP clients by rogue NTP ser...

Page 80: ...iles etc hosts allow and etc hosts deny which are configured using the interactive script accessconfig See Restrict Access Telnet SSH and SNMP below Insecure protocols like Time Daytime and Telnet may...

Page 81: ...s directly and then copy them to the boot etc directory See Appendix C Helpful Linux Information Using Editors Be careful to maintain the proper ownership and access permissions by using cp p when cop...

Page 82: ...omodify noquery nopeer restrict 127 0 0 1 nomodify restrict 0 1 nomodify The first line eliminates control and query access from ALL hosts The second and third lines disable the localhost from making...

Page 83: ...aemon itself and in telnetd Any one or all of these may be enabled or disabled for start up Disable SNMP SSH and HTTPS To disable SNMP SSH or HTTPS you only have to modify the file mode of the scripts...

Page 84: ...root root 1144 Feb 19 01 52 rc httpd rw r r 1 root root 1168 Oct 26 2012 rc snmpd rw r r 1 root root 2684 Feb 18 02 16 rc sshd If rc httpd rc snmp or rc ssh is not listed or it is listed and there is...

Page 85: ...ur remote computer as id_rsa or id_dsa If you are unfamilar with this process refer to the man page for the ssh keygen utility for details issue man ssh keygen at the prompt Be careful to maintain the...

Page 86: ...directory You must reboot Meridian II for them to take effect An excellent book which describes operation and configuration of the various HTTPS directives and SSL configuration is Professional Apache...

Page 87: ...ou are planning to operate with SNMPv3 it is highly recommended that you make use of both of these resources to familiarize yourself with the agent configuration concepts SNMPv3 Security Prior to SNMP...

Page 88: ...stem start up script By default it will listen on port 161 for SNMP queries from the network management system If you would like to have it listen on another port you could edit the file and change th...

Page 89: ...dian II enter prise MIB trap generation mechanism will only send a trap to the last declared trapsink in the file Configuring SNMPv2c Notifications and Informs To have your Meridian II send SNMPv2c no...

Page 90: ...se two lines to define your v3 users and their access parameters rwuser root priv 1 rouser Meridian2 auth 1 3 6 1 4 1 13827 The first line defines a SNMPv3 read write user root whose minimum security...

Page 91: ...ecret key s to the file These lines begin with the string usmUser In this way un encrypted passwords are not stored on the system IMPORTANT To generate new keys stop the snmpd process delete the exist...

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Page 93: ...not be using MD5 authentication If the clients are using MD5 authentication they must be configured properly with the same MD5 authentication keys as Meridian II If you need to modify the factory defa...

Page 94: ...e to configure the time to live of the multicast packets The changes you make now will not take effect until you re boot the Meridian II GPS If you make a mistake just re run ntpconfig prior to re boo...

Page 95: ...st multicast address for the Meridian II GPS to use For broadcast mode on IPV4 networks this address is the all 1 s address on the sub net Example 111 112 113 255 On IPV6 networks there is more than o...

Page 96: ...in it will switch back to Stratum 1 operation 2 When you want your Meridian II to serve accurate time but you don t want to use the antenna for some reason In this case Meridian II can operate solely...

Page 97: ...ocols time ntp Three methods of using Meridian II with NTP clients on Unix like platforms will be described Basic This is the simplest and will operate without MD5 authentication NTP beginners should...

Page 98: ...on in debug mode ntpd d to confirm successful con figuration Refer to the NTP documentation for detailed usage of these debug utilities Unix like Platforms MD5 Authenticated NTP Client Setup MD5 authe...

Page 99: ...this example key 1 server 192 168 1 120 key 1 Restart ntpd to have it begin using the Meridian II server with MD5 authentication Use the NTP utility ntpq to check that ntpd is able to communicate with...

Page 100: ...ve will be assumed in the example configuration commands shown here You have installed NTP on your client computer You have successfully performed the Unix like Platforms MD5 Authenticated NTP Client...

Page 101: ...ian II server which you have just configured You should verify that it is being reached You may have to continue issuing the peers command for a minute or two before you will see the reach count incre...

Page 102: ...entication However it is highly recommended that authentication be configured when using broadcast multicast mode due to the relative ease with which a fake NTP server can take over the clock setting...

Page 103: ...after issuing the command ntpq you will see the ntpq exe command prompt ntpq Use the command peers to display the NTP peers which your computer is using One of them should be the Meridian II server w...

Page 104: ...ogram files ntp etc ntp keys file is the weak link in the MD5 authentication scheme It is very important that it is owned by administrator and not readable by anyone other than administrator After tra...

Page 105: ...rror in the ntp conf file that causes the needed key to not be included in the trustedkey list Windows Broadcast Multicast NTP Client Setup Broadcast multicast client setup is relatively simple if You...

Page 106: ...ntp conf file multicastclient 224 0 1 1 or for IPv6 multicastclient ff05 101 If you are not using MD5 authentication you would add these lines disable auth multicastclient 224 0 1 1 or for IPv6 disabl...

Page 107: ...nd associations to display the characteristics of the client server associations In the auth column of the display you should see OK for the row corresponding to the Meridian II server If you see bad...

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Page 109: ...play Either method will allow you to configure your Ethernet interface for both IPv4 and IPv6 operation Using the netconfig script has the advantage that you can also configure the hostname and domain...

Page 110: ...bind to any IPv6 addresses Refer to the NTP documentation for details on the interface directive IPv4 Only Protocols There are several protocols running on Meridian II which are not IPv6 capable telne...

Page 111: ...cellent book which describes the PTP Master and Slave operation is Measurement Control and Communication using IEEE 1588 John C Eidson Springer November 2006 More information on IEEE 1588 PTP can be f...

Page 112: ...ese settings then you will need to reconfigure the PTP Subsystem Default PTP settings are Port 0 eth0 Port 1 eth1 Sync Interval 1 second 1 second Announce Inverval 2 seconds 2 seconds Priority 1 128 1...

Page 113: ...ffect The following is a transcript of the question and answer configuration utility provided by ptpcon fig0 or ptpconfig1 The user entered parameters are underlined Meridian II root host ptpconfig0 P...

Page 114: ...ffect Now reboot the system by issuing this command at the shell prompt reboot PTP Status Using the Network or Serial Port The ptpstat0 or ptpstat1 command allows you to query the status of the PTP Su...

Page 115: ...e indicator either TRUE or FALSE TM is the PTP transmission mode either MULTICAST or HYBRID PTP Operation The Meridian II is configured as an IEEE 1588 Grandmaster Clock default profile Verify that th...

Page 116: ...he Clock Class is UNLOCKED when the GPS Subsystem TFOM level is 9 The PTP Timescale either PTP or ARB When Time Mode is configured to PTP the clock transmits the Timescale as PTP When the Time mode is...

Page 117: ...e is either Multicast or Hybrid Multicast Mode is the default and is de fined in the IEEE 1588 standard All packets sent from the Grandmaster are Multicast Hybrid Mode uses Multicast and Unicast In th...

Page 118: ...tocol The instructions below assume that the PTP Option has been installed on Port 0 eth0 of your Me ridian II To check see the section titled Option at the beginning of this chapter To disable the Pr...

Page 119: ...iewed and modified via the front panel keypad display or the console port Methods to do this are described in this chapter Refer to Chap ter 9 PTP IEEE 1588 for details on the Precision Time Protocol...

Page 120: ...any connector on the CPU Module that has an optional I O signal Connectors are identified as A B or C Select the particular connector I O A I O B or I O C to see which signal is installed Or you can u...

Page 121: ...nal Connectors are identified as A B or C Select the particular connector I O A I O B or I O C to see which signal is installed Or you can use this console port command Command cpuio MeridianII reply...

Page 122: ...signal definition see Appendix K Specifications Optional Programmable Pulse Out put on CPU Module View and Change the PPO On the front panel display traverse to the Main Menu and then to CPU_I O This...

Page 123: ...f day for the trigger with 1 second resolution CR is the ASCII carriage return character 0x0D An example is shown here Command triggerppo A 13 50 00 This will cause a pulse on BNC A at MeridianII repl...

Page 124: ...play lists any connector on the CPU Module that has an optional I O signal Connectors are identified as A B or C Select the particular connector I O A I O B or I O C to see which signal is installed O...

Page 125: ...e Main Menu and then to CPU_I O This display lists any connector on the CPU Module that has an optional I O signal Connectors are identified as A B or C Select the particular connector I O A I O B or...

Page 126: ...600 Current Serial Time Output Format Setting SYSPLEX Current Serial Time Output Parity Setting ODD Current NMEA Sentence 1 Setting NONE Current NMEA Sentence 2 Setting NONE Current NMEA Sentence 3 Se...

Page 127: ...e console port see systimemodeconfig in Chapter 9 Console Port Control and Status The following string is sent once each second T YYYY DDD HH MM SS zZZ m CR LF T is the Time Figure of Merit character...

Page 128: ...e ASCII line feed character 0x0A NENA Format NENA is the National Emergency Number Association This organization has adopted several ASCII time code formats for use in PSAPs Public Safety Answering Po...

Page 129: ...the unsynchronized condition is the space character 0x20 YYYY is the four digit year DDD is the day of year 001 366 is the colon character 0x3A HH is the hour of the day 00 23 MM is the minute of the...

Page 130: ...or 0 fix not valid 1 GPS fix Field 7 08 Number of SVs in use 00 08 Field 8 1 2 HDOP horizontal dilution of precision Field 9 14 5 Altitude above WGS84 ellipsoid we do not calculate mean sea level Fiel...

Page 131: ...fix on channel 8 empty if no SV Field 11 17 PRN of SV used for fix on channel 9 empty if no SV Field 12 1 PRN of SV used for fix on channel 10 empty if no SV Field 13 empty field PRN of SV used for f...

Page 132: ...round is in knots Field 7 0 14 Speed over ground km hr Field 8 K Fixed text K shows speed over ground is in km hr Field 9 A A autonomous mode N data not valid Checksum 74 Msg End CR LF ZDA Time and Da...

Page 133: ...reside in slots four and five But in a 2U chassis they reside in slots six and seven View the Plug in Options On the front panel display traverse to the Main Menu and then to Opt_Cards This display l...

Page 134: ...2 Front Panel Keypad Display Or you can program the outputs via the network or serial port by using console command pluginoptsconfig see Chapter 3 Console Port Control Status Digital Output Module Tim...

Page 135: ...7 All four output connectors use the same code format The format is identical to that of the Receiver CPU Module AM Code output which is set via console command systemioconfig Chapter 3 Console Port C...

Page 136: ...hese modules can be installed The first one with an oscillator needs to be installed and configured at the factory Additional modules can be installed in the field as plug and play op tions Available...

Page 137: ...lay option that adds two or three outputs to your Merid ian II Two outputs are available for any combination of T1 J1 E1 and Composite Clock An alarm relay output is also available as an additional op...

Page 138: ...nd Display or by using the console commands pluginopts and pluginoptsconfig see Chapter 3 Control and Status Commands Available selections for each user setting are T1 Framing Mode Unframed SF D4 and...

Page 139: ...119 M e r i d i a n I I U s e r M a n u a l R E A R P A N E L I O...

Page 140: ...performance masks This is the last fault listed in the table above MTIE Exceeds 1 Microsecond The following chart shows the G 823 and T1 101 jitter wander MTIE mask levels that are pertinent to the t...

Page 141: ...O Connectors and Cables The Telecom Clock Output Module is available with two types of output connectors BNC and RJ48C The BNC connector is compatible with 75 ohm coaxial cable The RJ48C connector is...

Page 142: ...ck Ring input wire wrap terminal and the wire connected to pin 5 connects to the BITS clock Tip input wire wrap terminal The drain wire associated with that shielded twisted pair connects to the GROUN...

Page 143: ...s are not changeable but can be viewed via the front panel display by navigating to Main Menu Option I O OptCard1 You can also view the Low Phase Noise output configuration via the network or serial p...

Page 144: ...and stable means of measuring the phase of the 5071A versus GPS and ultimately UTC USNO The 5071A has the ability to be steered with very fine resolution about 6 3 parts in 1015 By combining these tw...

Page 145: ...rrent Electron multiplier voltage Cesium Beam tube oven voltage Signal Gain percent of maximum 1st microwave RF amplitude percent of maximum 2nd microwave RF amplitude percent of maximum Reference osc...

Page 146: ...14 4 of maximum RF Amplitude 1 35 7 of maximum RF Amplitude 2 34 9 of maximum Osc Oven Voltage 9 0 V Osc Control 3 40 of maximum or if the 5071A Cesium Control Module is not installed Command hp5071as...

Page 147: ...ent of maximum 0 to 100 typical RF Amplitude 2 percent of maximum 0 to 100 typical Oscillator Oven voltage 5 to 10 V typical Oscillator Control percent of maximum 95 to 95 typical Example response Ope...

Page 148: ...tive output of the DC power source Note that Meridian II has a floating internal power supply therefore either the positive or negative output of the DC power source can be referenced to earth ground...

Page 149: ...m Masking a fault will prevent it from causing the Alarm LED and Alarm Output if any from going active Masking a fault will NOT prevent it from showing on the front panel System Faults display or in t...

Page 150: ...next to the Oscillator Module or next to the highest numbered slot LPN Sine Module Due to the jumper cables all previously installed LPN Buffer Modules and or the Oscillator Module must be removed sim...

Page 151: ...ion for night to day variations in the ionosphere It is unable to compensate for the much shorter term variations in the ionospheric delay caused by various types of solar storms and it cannot keep up...

Page 152: ...s sent to NIST in May of 2016 where its 1PPS output was monitored continuously relative to UTC NIST for over 30 days The RTIC Option was active in the Meridian II during this time The ionospheric dela...

Page 153: ...n II reply The Real Time Iono Corrections Option is Installed If the option is installed If you need information on how to install the RTIC option refer to Appendix I Software Options RTIC Configurati...

Page 154: ...calculated and used to compensate for the GPS signal delay through the ionosphere When OFF the Real Time delays continue to be calculated but the standard broadcast Klobuchar ionospheric model delays...

Page 155: ...s e r M a n u a l R E A L T I M E I O N O S P H E R I C C O R R E C T I O N S R T I C RTIC Performance Plots Using the HTTP Interface Plots showing the Ensemble Ionosphere Delays are available on the...

Page 156: ...10 12 4 0x10 13 10 2 0x10 10 3 9x10 12 1 3x10 12 4 5x10 13 100 8 0x10 11 3 0x10 12 1 7x10 12 8 5x10 13 1000 8 0x10 12 2 0x10 12 1 3x10 12 7 0x10 13 10000 6 0x10 13 2 0x10 13 2 0x10 13 2 0x10 13 100000...

Page 157: ...adable at distances in excess of 15 feet The keypad consists of an eight key switch assembly designed to allow easy parameter selection and control Keypad Description The front panel keypad consists o...

Page 158: ...he parameter is correct press ENTER to load the new value All entered values are stored in non volatile FLASH and restored after a power cycle If you wish to abort the edit process press BACK This wil...

Page 159: ...ar displays from the Time Status display The displays available through the Shortcut Menu are the Receiver Status GPS Reference Position Faults and NTP Status To select the Shortcut Menu press ENTER f...

Page 160: ...plays CPU_Stat Receiver Faults Network NTP Clock Display Firmware and About In addition Sys_I O CPU_I O and PTP displays may be present if your Meridian II has these optional features CPU Status This...

Page 161: ...er and indicates that no satellite is being tracked on that channel Valid SV numbers range from 1 to 32 Azimuth and elevation are in degrees and C No is in dB Receiver Reference Position Ref_Pos This...

Page 162: ...on Receiver Last Fix Position Last_Fix This display provides the last computed GPS position When tracking four or more satellites the GPS Receiver provides a 3D position fix The last fix position is n...

Page 163: ...between the GPS antenna and the Meridian II GPS receiver This is required for the Meridian II to synchronize with maximum accuracy to UTC See Appendix E Installing the GPS Antenna Calibrate Your Recei...

Page 164: ...s open circuit SHRT GPS Antenna is short circuit Faults Antenna Fault Mask AntFltMask This setting allows you to prevent the antenna fault from creating an alarm conditon Some instal lations may need...

Page 165: ...The Inhibit function allows you to prevent the timing signals such as 1 PPS and time code from being output until the Meridian II has achieved a first time lock status CPU Module I O Menu CPU_I O The...

Page 166: ...The NTP offset indicates the accuracy of the NTP system clock relative to the GPS Subsystem clock Initially if the offset between the NTP system clock and the GPS Subsystem clock is large the display...

Page 167: ...the system reboots The new parameters are loaded to the ntp conf file in the boot etc directory Only the broadcast line in the ntp conf file is modified The final display in the edit sequence require...

Page 168: ...nd contains parameters related to the functioning of the front panel display There are two parameters an intensity setting and a screensaver setting The intensity setting allows you to set the brightn...

Page 169: ...e Compensated Crystal Oscillator TCXO Oven Controlled Crystal Oscillator OCXO or Rubidium oscillator The extrapolated TFOM is based on a conservative estimate of the performance of the os cillator and...

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Page 171: ...low the prompts from the HTTPS interface to complete each upgrade as needed IMPORTANT The domain name server IP address is required by the Apache web server When using netconfig see Chapter 3 Console...

Page 172: ...ill be using later to access the Meridian II via its HTTPS interface Use this link to get the file s you want http www endruntechnologies com upgrademeridian2 htm After saving the file s use the Merid...

Page 173: ...rforming an upgrade you will be erasing and then copying the new image to this device First you need to download the Linux RFS firmware from the EndRun website to a place on your network which is acce...

Page 174: ...have entered your password the system version message will be displayed You should notice that it now indicates the software version and date of the upgrade that you previously downloaded You can als...

Page 175: ...ered If the system boots normally then you should resolve the problems with the previous root file system upgrade and re perform it Performing the Linux Kernel Upgrade First you need to download the L...

Page 176: ...is to be printed to the console BOOTED KERNEL IMAGE 1 Upgrade If so and your unit seems to be operating normally you have successfully completed the kernel upgrade If your unit does not boot up succes...

Page 177: ...mple F W 6010 0076 101 then contact the factory You may transfer the file to your Meridian II using either ftp or scp If you are using ftp to per form the upgrade transfer the previously downloaded fi...

Page 178: ...iver firmware from the EndRun website to a place on your network which is accessible to the Meridian II The link to the Meridian II upgrade page is shown above You may transfer the file to your Meridi...

Page 179: ...grammable Gate Array FPGA resident on the GPS Receiver This is rarely if ever used so is not an option on the HTTPS interface If you want to upgrade the GPS Receiver see the section above called Perfo...

Page 180: ...You will see a file trans fer progress message while it is performing the transfer Next issue the following command to the Meridian II console to reset the GPS Subsystem and Receiver subsysreset After...

Page 181: ...ll not be able to modify any system settings or view secure files For security reasons we recommend you change the default passwords using the Linux passwd com mand see Change Password below Linux Com...

Page 182: ...s It affects the serial port SSH Telnet and HTTPS passwd List Active Processes This command displays all active processes running in the system ps e NTP Monitoring and Troubleshooting The following co...

Page 183: ...ded on the Meridian II file system for legacy reasons since it has been the default editor for all first and second generation EndRun Technologies products A man page for edit is resident on the syste...

Page 184: ...he rc M file into a location that will ensure your changes persist through a system reset Copy etc rc d rc M to boot etc rc d as shown cp etc rc d rc M boot etc rc d For more details on ethtool and ho...

Page 185: ...are designed to take away your freedom to share and change it By contrast the GNU General Public License is intended to guarantee your freedom to share and change free software to make sure the softwa...

Page 186: ...lder saying it may be distributed under the terms of this General Public License The Program below refers to any such program or work and a work based on the Program means either the Program or any de...

Page 187: ...ole must be on the terms of this License whose permissions for other licensees extend to the entire whole and thus to each and every part regardless of who wrote it Thus it is not the intent of this s...

Page 188: ...e your acceptance of this License to do so and all its terms and conditions for copying distributing or modifying the Program or works based on it 6 Each time you redistribute the Program or any work...

Page 189: ...the Free Software Foundation 10 If you wish to incorporate parts of the Program into other free programs whose distribution condi tions are different write to the author to ask for permission For sof...

Page 190: ...mission notice appear in supporting documentation and that the name University of Delaware not be used in advertising or publicity pertaining to distribution of the software without specific written p...

Page 191: ...e called Apache nor may Apache appear in their name without prior written permission of the Apache Software Foundation THIS SOFTWARE IS PROVIDED AS IS AND ANY EXPRESSED OR IMPLIED WARRANTIES INCLUDING...

Page 192: ...This notice applies as if the text was explicitly included in each file Copyright c 2005 2008 Kendall Correll Aidan Williams Permission to use copy modify and or distribute this software for any purp...

Page 193: ...ppendix K Specifications assume an antenna installation with a very good view of the sky Antenna Location The location of the antenna must be chosen based on having as clear a view of the sky as possi...

Page 194: ...uities in the transmission cables All RF coax cables have a minimum bend radius In order to prevent damage cable should not be bent into tight curves It is critically important during installation tha...

Page 195: ...mportant for long cable runs For very long cables if the DC resistance is too high not enough voltage will be available at the end farthest from the Meridian II where the antenna and preamplifiers are...

Page 196: ...le shield and back up to the antenna This highlights the importance of properly constructed cable terminations and double shielded cable IMPORTANT Proper installation of two or three LNAs is critical...

Page 197: ...installing a signal splitter keep these points in mind 1 The splitter must be DC blocked on one leg The GPS Receiver in EndRun s products provide 5 VDC up the coax to power the GPS antenna s built in...

Page 198: ...the most demanding timing applications it is recommended that the delay between the antenna and Meridian II receiver input be precisely measured EndRun Part Description Nominal Delay Notes Antenna Ca...

Page 199: ...GPS reference position or a manually entered GPS reference position If you need to provide a reference position to your Meridian II it is best to use a previously determined position from the unit its...

Page 200: ...M e r i d i a n I I U s e r M a n u a l 180 A P P E N D I X E FIGURE 1 GPS ANTENNA ROOFTOP MOUNTING HARDWARE...

Page 201: ...181 M e r i d i a n I I U s e r M a n u a l I N S TA L L I N G T H E G P S A N T E N N A FIGURE 2 GPS ANTENNA ROOFTOP MOUNTING HARDWARE WITH PREAMPLIFIER...

Page 202: ...M e r i d i a n I I U s e r M a n u a l 182 A P P E N D I X E This page intentionally left blank...

Page 203: ...serted from time to time in order to keep UTC which is derived from atomic time TAI in agreement with the Earth s rotation rate Relative to TAI the Earth s rotation rate is slowing down This means tha...

Page 204: ...M e r i d i a n I I U s e r M a n u a l 184 A P P E N D I X F This page intentionally left blank...

Page 205: ...If your Meridian II has the Dual Power Supply option then you may mask primary and or secondary power supply faults See Chapter 10 Options Masking Dual Power Supply Fault Alarms for more information...

Page 206: ...elow Receiver Faults for more information System Oscillator PLL Phase Lock Loop This fault indicates that there is an unlock condition between the main system oscillator and the other system timebase...

Page 207: ...DAC endpoint The unit should be re turned to the factory for oscillator replacement at your convenience GPS Signal SIG This fault indicates that the GPS Receiver has not been able to acquire a GPS sig...

Page 208: ...ain oscillator has failed This is a fatal fault Please contact EndRun Customer Support Antenna Short SHRT This fault indicates that the GPS antenna has an overcurrent condition short Antenna Open OPEN...

Page 209: ...sed to amplitude modulate a 1000 kHz sine wave carrier The information contained in the time code is seconds through day of year coded in Binary Coded Decimal BCD Reference IRIG Document 200 004 IRIG...

Page 210: ...t sign 0 1 P65 Local offset binary 1 Local offset from UTC time P66 Local offset binary 2 P67 Local offset binary 4 P68 Local offset binary 8 P69 P7 Position identifier P70 Local offset half hour bit...

Page 211: ...t command You must be logged in as the root user in order to run this command and you must provide a license key on the command line If the key is verified then the option will be enabled Command wrt_...

Page 212: ...31 from right to left Currently there are only three software options defined in the Meridian These are for the RTIC Option and PTP IEEE 1588 enabled on port 0 eth0 or port 1 eth1 The table below show...

Page 213: ...onfusing simulation results and or improper operation when the Meridian II is subsequently recon nected to live GPS signals Console Port Commands clearalmanac The GPS Subsystem maintains a record of t...

Page 214: ...n the future relative to the simulator time If lock to the simulator is then achieved this future time will then be saved to non volatile memory as the Last GPS Week Number Subsequent runs with the si...

Page 215: ...ithm Issuing this command will reset the stored GPS Leap Second History to the history that was correct at the build date of the receiver firmware As long as the firmware build date is not too many ye...

Page 216: ...M e r i d i a n I I U s e r M a n u a l 196 A P P E N D I X J...

Page 217: ...pable of operation over 40 C to 85 C Mounting via 18 long 3 4 pipe with stainless steel clamps 50 low loss RG 59 downlead cable standard Extension cables and low noise pre amplifiers are available Tim...

Page 218: ...formance TP Timestamp Accuracy 10 microseconds 7500 requests second Supported IPv4 Protocols SNTP NTP v2 v3 v4 SHA MD5 authentication broadcast multicast and autokey SSH client and server with secure...

Page 219: ...OL max 0 4V VOH min 2 4V VOH nom 2 5V VOH max 3 0V Width User selectable to 20 us 1 ms 100 ms 500 ms User Calibration 500 us 1 ns resolution Accuracy 10 nanoseconds RMS to UTC USNO when locked Stabili...

Page 220: ...sing Storage Humidity 5 to 95 RH non condensing Maximum Operating Altitude AC 13 125 ft 4000 meters 12 24 VDC 13 125 ft 4000 meters 48 VDC 61 VDC Max 13 125 ft 4000 meters 48 VDC 60 VDC Max 6 562 ft 2...

Page 221: ...r 0 NTP Stratum 1 Holdover 1 000 000 days Optional 5071A Cesium Control Module with High Performance Beam Tube HP Cs Temp Stability 1x10 13 for all environmental effects Ageing Rate Year 0 NTP Stratum...

Page 222: ...153 110 z Rb US Rb Cs HP Cs Spurs 1 80 92 85 100 10 100 135 125 130 120 100 135 148 135 135 115 1k 145 154 140 140 125 10k 145 155 145 145 125 100k 145 155 145 145 110 System Oscillator Phase Noise Ta...

Page 223: ...ote For more information see Chapter 10 Rear Panel I O DC Power Input Optional Dual Redundant Power Supplies Any combination of Universal AC and or DC supplies Note For more information see Chapter 10...

Page 224: ...Format User selectable to IRIG B 000 IEEE 1344 002 003 NASA 36 2137 Rise Time 2 nanoseconds TTL 3 nanoseconds RS 422 Alignment Within 5 ns of the other TTL outputs in this unit except the optional DDS...

Page 225: ...ise Time 2 nanoseconds TTL 3 nanoseconds RS 422 Alignment Within 5 ns of the other TTL outputs in this unit except DDS if any Connector Rear panel BNC jack labeled 10MPPS Note For more information ref...

Page 226: ...on Table above Phase Noise See System Oscillator Phase Noise Table above Alignment Not aligned with other outputs in this unit Connector Rear panel BNC jack Note See Chapter 10 Rear Panel I O 5071A Ce...

Page 227: ...Output D Note See Chapter 10 Rear Panel I O Digital Output Module for more information Programmable Pulse Output Rate User selectable to 1 10 100 1K 10K 100K 1M 5M 10M PPS 1PPM 1PP2S Inv1PPS Duty Cyc...

Page 228: ...oS at Critical Red Alarm Connector RJ 45 style modular jack RJ48C compatible 1 per output or BNC single ended or DB9M RJ48C Pinout Pin 4 is Clock Out Ring Pin 5 is Clock Out Tip DB9M Pinout Pins 1 5 7...

Page 229: ...r Alarm Indication Signal AIS or Status Sync Messaging SSM or none at Major Blue Alarm All zeros LoS at Critical Red Alarm Connector RJ 45 style modular jack RJ48C compatible 1 per output or DB9M RJ48...

Page 230: ...EE Directive 2012 19 EC Supplementary Compliance Data Safety EN60950 1 2006 A11 2009 A1 2010 A12 2011 EMC EN55024 2010 EN55032 2012 C1 EN61000 3 2 2014 EN61000 3 3 2013 VCCI V3 2014 04 EN301 489 3 V1...

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Page 232: ...M a n u a l 212 A P P E N D I X K EndRun EndRun EndRun EndRun TECHNOLOGIES TECHNOLOGIES TECHNOLOGIES TECHNOLOGIES EndRun EndRun EndRun EndRun TECHNOLOGIES TECHNOLOGIES TECHNOLOGIES TECHNOLOGIES MERIDI...

Page 233: ...a n u a l S P E C I F I C AT I O N S EndRun EndRun EndRun EndRun TECHNOLOGIES TECHNOLOGIES TECHNOLOGIES TECHNOLOGIES EndRun EndRun EndRun EndRun TECHNOLOGIES TECHNOLOGIES TECHNOLOGIES TECHNOLOGIES ME...

Page 234: ...M a n u a l 214 A P P E N D I X K EndRun EndRun EndRun EndRun TECHNOLOGIES TECHNOLOGIES TECHNOLOGIES TECHNOLOGIES EndRun EndRun EndRun EndRun TECHNOLOGIES TECHNOLOGIES TECHNOLOGIES TECHNOLOGIES MERIDI...

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Page 236: ...M e r i d i a n I I U s e r M a n u a l 216 A P P E N D I X K...

Page 237: ...ications Changes for Customer Requirements From time to time EndRun Technologies will customize the standard Meridian II Precision TimeBase for special customer requirements If your unit has been modi...

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Page 240: ...2270 Northpoint Parkway Santa Rosa CA 95407 TEL 1 877 749 3878 FAX 707 573 8619 www endruntechnologies com Smarter Timing Solutions...

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