EndRun Meridian II User Manual
  1. Manuals
  2. Brands
  3. EndRun Manuals
  4. Time Base
  5. Meridian II
  6. User manual

EndRun Meridian II User Manual

Precision timebase. gps-synchronized
Hide thumbs
Table of Contents

Advertisement

Quick Links

Meridian II
GPS-Synchronized
User Manual
USM3043-0000-000 Revision 8
April 2019
Precision TimeBase
"Smarter Timing Solutions"

Advertisement

Table of Contents
loading
Need help?

Need help?

Do you have a question about the Meridian II and is the answer not in the manual?

Questions and answers

Subscribe to Our Youtube Channel

Summary of Contents for EndRun Meridian II

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

  • Page 3: Preface

    Coordinated Universal Time (UTC) that you can deploy quickly, easily and reliably. Your new Meridian II is fabricated us- ing the highest quality materials and manufacturing processes available today, and will give you years of troublefree service.

  • Page 4: About This Manual

    Extended Warranty EndRun products are very reliable and rarely need to be returned to the factory for service. After the initial warranty period it is most cost-effective for the customer to repair the unit on an “as needed ba- sis”, rather than pay for an extended warranty or the annually recurring fees of a service contract.

  • Page 5: Warranty Repair

    If the warranty period has expired, we offer repair services for equipment you have purchased from EndRun. Call and ask for a customer service agent. It is important to contact us first as many prob- lems may be resolved with a phone call. Please have the serial number of the unit and the nature of the problem available before you call.

  • Page 6: Table Of Contents

    ..........6 Meridian II Physical Description .
  • Page 7 ........17 Connecting Instruments to the Meridian II Chapter Three - Console Port Control and Status .
  • Page 8 ............. 30 gpstrkstat .
  • Page 9 ............39 setrticmode (Optional) .
  • Page 10 ............. 51 Plots Page .
  • Page 11 ........73 Configuring the Meridian II as a Stratum 1 Server .
  • Page 12 ..........80 Configure NTP Client for Broadcast .
  • Page 13 ............107 EndRun Format .
  • Page 14 ............108 NENA Format .
  • Page 15 ........... 131 Our Proprietary Solution .
  • Page 16 ............143 Faults Menu .
  • Page 17 ..........153 Transfer File to Meridian II .
  • Page 18 ............175 Recommended Cable .
  • Page 19 Appendix J - Operation with a GPS Simulator ......193 ............193 Background .
  • Page 20 This page intentionally left blank. M e r i d i a n I I U s e r M a n u a l...

  • Page 21: Chapter One - Introduction

    Units equipped with our Ultra-Stable OCXO provide unmatched close-in phase noise performance and short-term stability. The Meridian II uses GPS transmissions to precisely synchronize its clock within 10 nanoseconds of Coordinated Universal Time (UTC). The frequency of the internal oscillator is disciplined to match the frequency of the UTC timescale to less than 1 part in 10 over 24-hour observation intervals.

  • Page 22: Standard Features

    Firmware and configurable hardware parameters are stored in non-volatile FLASH memory, so the Meridian II can be easily and securely upgraded in the field using SSH and SCP or the local RS-232 serial port. Upgrades via FTP and Telnet are also possible although these protocols are not secure.

  • Page 23: Gps Timing-How It Works

    FIGURE 1 - M E RDIAN I I G P S SY STE M TIM E BASE GPS Timing-How It Works The time and frequency engine in the Meridian II receives transmissions from satellites that are oper- ating in compliance with the Navstar GPS Interface Specification known as IS-GPS-200. It specifies the receiver interface needed to receive and demodulate the navigation and time transfer data con- tained in the GPS satellite transmissions.

  • Page 24: Where To Use It

    Since signals from the GPS satellites are available at all locations on the globe, you may deploy the Meridian II virtually anywhere. However, you must be able to install an antenna with good sky vis- ibility, preferably on the rooftop.

  • Page 25: Chapter Two - Basic Installation

    Hardware Unpack and check all the items using the shipment packing list. Contact the factory if anything is missing or damaged. The Meridian II Precision TimeBase shipment typically contains: • Meridian II 1U (part #3043-xxxx-xxx (1U) or #3045-xxxx-xxx (2U)) •...

  • Page 26: Meridian Ii Physical Description

    C H A P T E R T W O Meridian II Physical Description The front-panel drawing below shows the 1U version of the Meridian II. There is also a 2U chassis available.  � � ��   ������������������...
  • Page 27 B A S I C I N S T A L L A T I O N 1 PPS Output This BNC connector provides the 1 PPS TTL output. The pulse width is normally 1 millisecond wide when shipped from the factory but can be changed via the front-panel keypad or via console command .

  • Page 28: Performing A Site Survey

    Performing a Site Survey Using the front panel status LED indicators, it’s easy to find out if your Meridian II will work in your desired location: 1.Temporarily mount the antenna on the roof. Make sure that it is not blocked by large metallic ob- jects closer than one meter.

  • Page 29: Installing The Meridian Ii

    EndRun Customer Support for assistance. NOTE In order for the Meridian II to synchronize with maximum accuracy to UTC, the delay for the cable and all devices between the antenna and the GPS receiver must be compensated. See Appendix E - Installing the GPS Antenna, Calibrate Your Receiver for more information.

  • Page 30: Connecting The Optional Dc Power

    If your network does use DHCP for host configuration, and you are in a hurry to get your Meridian II up and running, you may proceed to Verifying Network Configuration to make sure that the network parameters were set up correctly.

  • Page 31: Configuring Ethernet With The Serial Port

    NOTE You must use an RS-232 null-modem cable or adapter if you are connecting the Meridian II to another computer. The cable included in the shipping kit is a null-modem cable. If your computer does not have a serial port, you can use a USB port with a USB-RS232 converter similar to Gearmo GM-FTDI-8.
  • Page 32 These lines are the Linux bootloader boot prompts. These prompts will timeout after five seconds and the factory default Linux kernel and the factory default Meridian II root file system will be load- ed. When the Linux kernel is loaded from FLASH memory into RAM a long list of kernel-generated, informational messages is displayed as the kernel begins execution and the various device drivers are initialized.

  • Page 33: Using Netconfig To Set Up Your Ip

    The settings you make now will not take effect until you reboot your Meridian II GPS, so if you make a mistake, just re-run this script before * rebooting. You will be prompted to enter your IPV4/IPV6 network parameters now.

  • Page 34: Verify Network Configuration

    Meridian II GPS(root@Meridian II:~)-> reboot Verify Network Configuration If you are using the RS-232 serial I/O port to communicate with the Meridian II, you will be able to see the kernel-generated boot messages when the unit reboots. You should note the lines Configuring eth0 as 192.168.1.120...

  • Page 35: Check Network Operation

    If so, then the Ethernet interface of your Meridian II has been successfully configured to operate on your network and you are ready to check operation of the Meridian II over the network. If not, you should recheck your configuration and/or repeat the procedure.

  • Page 36: Using Telnet

    After correctly entering the password at this prompt, Password: the sign on message is shown. It identifies the host system as Meridian II GPS and shows the soft- ware part number, version and build date: Meridian II GPS 6010-0067-000 v 1.00 Sat Jan 19 14:17:44 UTC 2013 Meridian II GPS (root@Meridian II:~)->...

  • Page 37: Using Https

    Receiver State. (See Chapter 12 - Front-Panel Keypad and Display.) With this display in view you will always know whether the Meridian II is currently locked to a GPS signal while you are performing measurements based on its frequency outputs. The holdover frequency accuracy of the...
  • Page 38 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. M e r i d i a n I I U s e r M a n u a l...

  • Page 39: Chapter Three - Console Port Control And Status

    This chapter describes Meridian II control and status commands used via the Linux console. The console is accessed via any of the Ethernet ports or the RS-232 serial port. Meridian II supports sev- eral application-specific commands for configuration and for monitoring the performance and status of the Linux and GPS Subsystems.

  • Page 40: Available User Commands

    Prints the summary of all system fault states in a user-friendly format. get_sw_opts Prints the software options enabled in your Meridian II. See Appendix I - Software Options for more information. gpsdynmode Prints the GPS dynamic mode currently in effect.
  • Page 41 GPS. See the command. setinhibitoutputsmode installed_sw_opts Prints the software options enabled in your Meridian II. See Appendix I - Software Options for more information. ionostat Prints the status of the optional RTIC. See Chapter 11 - Real- (optional) Time Ionospheric Corrections for more information.

  • Page 42: Setrticmode (Optional)

    Prints the mode of the RTIC Option - either ON or OFF. See (optional) Chapter 11 - Real-Time Ionospheric Corrections for more information. serialnumber Prints the serial number of the Meridian II. setantfltmask Command to enable or mask the Antenna Fault. See the command.

  • Page 43: Subsysreset

    C O N T R O L A N D S T A T U S C O M M A N D S subsysreset Command that performs a GPS Subsystem reset. syskernel Prints the currently booted linux kernel, either 0 or 1, where 0 is the factory-installed kernel and 1 is the upgraded kernel.

  • Page 44: Detailed Command Descriptions

    RS-232 serial I/O port or from a session. telnet This script modifies these files: /etc/hosts.allow and /etc/hosts.deny. These are 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: accessconfig Meridian II reply:Interactive script is started.

  • Page 45: Cpuioconfig

    C O N T R O L A N D S T A T U S C O M M A N D S Command: cpuio MeridianII reply: CPU I/O A - AM TIME CODE OUTPUT is Installed -- Current Setting = (See systemio command) CPU I/O B - 1 PPS OUTPUT is Installed -- Current Setting = (See systemio command) CPU I/O C - PROGRAMMABLE PULSE OUTPUT is Installed --...

  • Page 46: Dumpephemeris

    C H A P T E R T H R E E ****** Week 1890 almanac for PRN-01 ******* Health: Eccentricity: 5.217074882e-03 Time of Applicability(s): 5.038080000e+05 Orbital Inclination(rad): 9.637917876e-01 Rate of Right Ascen(r/s): -7.828898418e-09 SQRT(A) (m 1/2): 5.153603027e+03 Right Ascen at Week(rad): -1.158766985e+00 Argument of Perigee(rad): +4.515030086e-01...

  • Page 47: Gpsdynmode

    This command displays the current GPS Subsystem dynamic mode of operation. It has two possible settings: OFF or ON. When it is OFF, it is assumed that Meridian II is installed in a stationary loca- tion. When it is ON, it is assumed that Meridian II is installed on a moving platform. Dynamic mode is intended for shipboard applications only.

  • Page 48: Gpslastfix

    WGS-84 ellipsoid. PDOP, HDOP, VDOP and TDOP are also shown. OORCnt is the out-of-range counter which may be non-zero when Meridian II has been moved more than 1 km from its previous location without being placed in UNKNOWN mode using command.
  • Page 49 C O N T R O L A N D S T A T U S C O M M A N D S LKSTAT TFOM = ? YEAR DOY HH:MM:SS LS LF S NN AGC EFCDAC C/No FLTR FLTS Where: LKSTAT is the tracking status of the GPS Subsystem, either LOCKED or NOTLKD.

  • Page 50: Gpstrkstat

    5071A Plug-in Option Configuration The Primary and Secondary Power Supply bits are only used if your Meridian II has the Dual-Re- dundant Power Supply option. The 5071A bit is used only if the 5071A Cesium Control Module is installed. The example reply below indicates that there has been a period without tracking a GPS signal that exceeded the time-out period, that there was a FLASH Write Fault and that there is an Antenna Fault.

  • Page 51: Gpsutcinfo

    F/W 6010-0076-000 Ver 1.00 - FPGA 6020-0016-000 Ver 01 - JUL 15 17:03:27 2015 help This command displays a list of Meridian II commands (not Linux commands). To get help on a particular command you would type , followed by the command.

  • Page 52: Hp5071Astat

    This script modifies the /etc/inetd.conf file, 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: Interactive script is started.

  • Page 53: Kplockstat

    This command prints the status, either locked or unlocked, of the front-panel keypad EDIT key. When the EDIT key is locked, it will prevent unauthorized tampering with the unit. All other keys are still enabled so you may continue to read the status and current settings of Meridian II. Refer to commands.

  • Page 54: Netconfig

    This command starts an interactive script that allows you to configure the IP network subsystem of Meridian II. By default, the unit is configured to configure itself using the Dynamic Host Configura- tion Protocol (DHCP). If you need to set up static IP configuration, you must run this script as root from the RS-232 serial I/O port during the installation process.

  • Page 55: Oscctrlstat

    C O N T R O L A N D S T A T U S C O M M A N D S HH:MM:SS is the hour, minute and second of the UTC timestamp of the most recent update received from the GPS Subsystem.

  • Page 56: Passwd

    C H A P T E R T H R E E MEASERR is the last measured time offset of the GPS Subsystem to GPS while locked, in seconds. TIMEDEV is the time deviation (TDEV) of the offset measurements in seconds. The tau associated with this measurement is three seconds, which is the update interval of the position fixes received from the GPS Receiver.

  • Page 57: Pluginoptsconfig

    Refer to Chapter 9 - PTP/IEEE-1588 for more information. pwrfltmask (Optional) See Chapter 10 - Rear-Panel I/O, Masking Dual Power Supply Fault Alarms for information on this command. rcvrserialnumber This command shows the serial number of the GPS Receiver in the Meridian II. Command: rcvrserialnumber MeridianII reply: 15080056...

  • Page 58: Resetlastgpswn

    (Optional) This command is only available if the RTIC option has been installed. Refer to Chapter 11 - Real- Time Ionospheric Corrections for more information. serialnumber This command shows the serial number of the Meridian II. Command: serialnumber MeridianII reply:...

  • Page 59: Setgpsrefpos

    You can invalidate an old position by setting the position mode to UNKNOWN. This will speed up the time it takes for Meridian II to acquire a new position and relock to the GPS signal. A cold start in unknown position mode should take about 20 minutes to lock, assuming a decent antenna installa- tion.
  • Page 60 C H A P T E R T H R E E setsigfltmask This command allows you to enable or mask the Signal Loss Fault. Parameter for this command is either MASKED or ENABLED. Setting this command to MASKED will prevent a signal loss fault from creating an alarm condition.
  • Page 61 C O N T R O L A N D S T A T U S C O M M A N D S sysosctype This command displays the installed system oscillator type. It is either TCXO, MS-OCXO, HS- OCXO, US-OCXO, Rubidium or US-Rubidium. The standard oscillator type is the TCXO. Command: sysosctype MeridianII reply:...
  • Page 62 C H A P T E R T H R E E YEAR is the year of the UTC timestamp of the most recent update received from the GPS Sub system. is the day-of-year of the UTC timestamp of the most recent update received from the GPS Subsystem.

  • Page 63: Triggerppo (Optional)

    This command starts an interactive utility that allows you to configure the time mode of the Time Code Output, the optional Serial Time output, or the front-panel display of Meridian II. These set- tings have no effect on the operation of the NTP daemon or the underlying Linux operating system time.

  • Page 64: Updatekernelflag 1

    This command allows you to update the configuration of the Linux bootloader after a new kernel image has been written to the UPGRADE kernel partition of Meridian II FLASH disk. You may also use it to reset the default back to the FACTORY kernel partition. Refer to Appendix B - Upgrading the Firmware, Performing the Linux Kernel Upgrade for detailed instructions for performing the upgrade procedure.

  • Page 65: Upgradercvrfpga

    C O N T R O L A N D S T A T U S C O M M A N D S Command: upgradercvr MeridianII reply: Upgrade progress is shown. upgradercvrfpga This utility allows you to upgrade the Field-Programmable Gate Array (FPGA) resident on the GPS Receiver.
  • Page 66 C H A P T E R T H R E E This page intentionally left blank. M e r i d i a n I I U s e r M a n u a l...
  • Page 67 This chapter briefly describes the HTTPS interface that resides on the Meridian II Precision Time- Base. The HTTPS interface to Meridian II is a fast and easy-to-use graphical interface that is com- patible with your standard web browser. Simply point your browser to the IP address of Meridian II and log in securely with HTTP over the Secure Socket Layer (SSL).

  • Page 68: Https Interface Description

    For proper operation, 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 are examples for IPv4 and IPv6: IPv4: http://192.168.1.1...

  • Page 69: Navigation

    The main menu tabs across the top of each webpage allow you to navigate through the status infor- mation in Meridian II while links on the left side of each webpage provide subcategory navigation. For example, in the page below the main menu tabs are: Home, Receiver, Plots, Clock, I/O, Faults, Network, NTP, PTP and Firmware.

  • Page 70: Home: Front Panel Page

    12% to 100%. Home: User Manual This link provides access to the Meridian II User Manual that is resident in the FLASH memory. The most recent version of the User Manual is on the EndRun website at: http://www.endruntechnologies.com/pdf/USM3043-0000-000.pdf...

  • Page 71: Plots

    For example, you can compare an NTP data plot with a CPU data plot. Plots files can also be downloaded from Meridian II as .PNG files. They can be found in the direc- tory /logs/png.

  • Page 72: Receiver: Receiver

    This field shows whether the dynamic mode is set or not. Dynamic mode should Mode be OFF when Meridian II is in a static (not moving) position. To change the dynamic mode setting use the gpsdynmode command. WGS-84 Reference Position...
  • Page 73 Real-Time Ionospheric Corrections (Optional) This section is for the optional RTIC. If your Meridian II does not have RTIC, then this section will not be shown. For more information on RTIC see Chapter 11 - Real-Time Ionospheric Corrections.

  • Page 74: Receiver: Oscillator

    Internal chassis temperature in °C. Available with OCXO or Rubidium Temperature oscillators. Clock Page This page shows the configuration of the Meridian II Precision TimeBase except for any optional I/O which is listed on the I/O page. Clock Configuration Time Mode This field shows the current time mode setting.

  • Page 75: I/O Page (Plug-In Options)

    Faults: System Faults Page This page lists all possible system fault conditions of Meridian II - the Linux Subsystem, the GPS Subsystem and the GPS Receiver. For details on each fault see Appendix G - System Faults. Faults: Fault Mask Page...

  • Page 76: Faults: Tfom Fault Level

    C H A P T E R F O U R Primary and These fields will display ONLY if your Meridian II has the Dual Power Supply option installed. See Chapter 10 - Rear Panel I/O, Masking Dual Power Secondary Power Supply Fault Alarms for more information.

  • Page 77: Ptp: Status And Configuration Pages (Optional)

    The fields on these pages show the status and the configuration for the optional PTP/IEEE-1588 pro- tocol. If your Meridian II does not have PTP enabled then there will be no fields shown. For more information on PTP and an explanation of the data fields on this page see Chapter 4 - PTP/IEEE- 1588.

  • Page 78: Firmware: Linux Kernel Upgrade

    This page is used for upgrading the firmware for the GPS Receiver. You must be logged in as “root” in order to have access to these pages. The latest released versions of Meridian II firmware are freely available on the EndRun Technologies website. For detailed information on how to perform the up- grade either via the network port, the serial port, or the HTTPS interface see Appendix B - Upgrad- ing The Firmware.

  • Page 79: Linux Operating System

    Many of these are standard multiple-user access control features of the underlying Linux operating system which controls the Meridian II. Others are pro- vided by the additional protocol servers selected for inclusion in your Meridian II, and the way that they are configured.

  • Page 80: Restrict Access

    Restrict Access - Telnet, SSH and SNMP By default, Meridian II is configured to allow access by all users via Telnet, SSH and SNMP. To ensure security and to protect against denial-of-service attacks, you should restrict access by using the command.

  • Page 81: Restrict Access - Https

    S E C U R I T Y This tells to deny access to to all hosts not listed in the /etc/ tcpd in.telnetd, sshd snmpd hosts.allow file. The daemons also parse this file directly prior to granting access to snmpd sshd a requesting host.

  • Page 82: Restrict Query Access - Ntp

    Knowledgable NTP users who would like to customize the security aspects of the configuration of the NTP daemon in Meridian II should edit the /etc/ntp.conf file directly and then copy it to the /boot/etc directory. Be sure to retain the ownership and permissions of the original file by using when cp –p...

  • Page 83: Disable Protocols

    -p /etc/rc.d/rc.snmpd /boot/etc/rc.d cp -p /etc/rc.d/rc.sshd /boot/etc/rc.d cp -p /etc/rc.d/rc.httpd /boot/etc/rc.d Reboot Meridian II when done for the changes to take effect. IMPORTANT After modifying /etc/rc.d/rc.snmpd, rc.sshd or rc.httpd, you must copy them to the /boot/etc/rc.d directory and reboot the system. It is very important to use the when performing the copy.

  • Page 84: Re-Enable Snmp, Ssh And Https

    OpenSSH The secure shell protocol server running in Meridian II is based on the portable OpenSSH for Linux. As such it supports both SSH1 and SSH2 protocol versions. By default, only SSH2 is enabled in Meridian II due to security issues with SSH1. For more information about OpenSSH, and to obtain client software, refer to the OpenSSH website: http://www.openssh.com...

  • Page 85: Configure Keys

    /boot/root/.ssh/authorized_keys2 file in the non-volatile FLASH area on your Meridian II. At boot time, Meridian II will copy these to the actual working /root/.ssh directory of the system ramdisk. To use this capability, the corresponding private key must reside in the /root/.ssh directory of your remote computer as id_rsa or id_dsa.

  • Page 86: Configure Certificate And Key

    -new -x509 -nodes -out server.crt -keyout server.key The two files will be created in the /boot/etc/httpd 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, Wainwright, Wrox Press, 1999.

  • Page 87: Snmpv3 Security

    "Smarter Timing Solutions" Chapter Simple Network Management Protocol (SNMP) Your Meridian II Precision TimeBase includes the NET-SNMP version 5.5.1 implementation of an SNMP agent, , and a SNMP notification/trap generation utility, . It supports all snmpd snmptrap versions of the protocol in use today: SNMPv1 (the original Internet standard), SNMPv2c (never reached standard status, often called “community SNMP”) and SNMPv3 (the latest Internet stan-...

  • Page 88: Enterprise Management Information Base (Mib)

    C H A P T E R S I X Enterprise Management Information Base (MIB) In addition to providing the SNMP variables contained in MIB-II as described in RFC-1213, EndRun Technologies has implemented an enterprise MIB using the syntax of the SMI version 2 (SMIv2) as described in RFC-2578:...

  • Page 89: Change Default Community Strings (Passwords)

    IP address or hostname of the destination host for receiving the notifica- xxx.xxx.xxx.xxx tions or informs generated by Meridian II. By default, the v2c trap or inform will be sent to port 162. You may optionally add another parameter,...

  • Page 90: Configuration Of Snmpv3

    Other aspects of the agent’s operation are also configurable in this file, but you should not need to modify those. To use the SNMPv3 capabilities of Meridian II, you must first set up user information and access limits for those users in /etc/snmpd.conf. Uncom-...

  • Page 91: Disable Or Restrict Access

    S I M P L E N E T W O R K M A N A G E M E N T P R O T O C O L ( S N M P ) Meridian2 to be created who may be authenticated using the Secure Hash Algorithm (SHA) with password Meridian2_0.
  • Page 92 C H A P T E R S I X This page intentionally left blank. M e r i d i a n I I U s e r M a n u a l...

  • Page 93: Configuring The Ntp Server

    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...

  • Page 94: Configuring Ntp Using The Network Interface Or Serial Port

    Enter a key number (1-65534) or 0 to quit: Meridian II Enter the key (1-31 ASCII characters): Writing key number: 2 and Key: Meridian II to ntp.keys M e r i d i a n I I U s e r M a n u a l...
  • Page 95 Enter a trusted key number (1-65534) or 0 to quit: ---NTP Broadcast/Multicast Configuration Would you like to enable broadcast/multicast server operation? ([y]es, [n]o) Set the network broadcast/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.

  • Page 96: Configuring The Meridian Ii As A Stratum 2 Server

    1. When you want a backup source of time. In this case, Meridian II will operate as a Stratum 1 Server as long as it is locked to the GPS signal. If it loses the signal, then Meridian II will start to drift away from “perfect”...

  • Page 97: Mask Alarm

    MD5: This method is trickier only because MD5 keys must be set up and distributed accurately to the NTP clients in a secure way. Meridian II is factory configured to authenticate its replies to NTP MD5 clients using its default set of keys.

  • Page 98: Unix-Like Platforms: Md5 Authenticated Ntp Client Setup

    Use the command peers to display the NTP peers which your computer is using. One of them should be the Meridian 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 increment.) If you have other peers configured, verify that the offset information for the Meridian II...

  • Page 99: Configure Ntp

    Modify the line added previously in Unix-like Platforms: Basic NTP Client Setup so that authenti- cation will be used with the Meridian II server using one of the trusted keys, in this example, key # 1: server 192.168.1.120 key 1 Restart to have it begin using the Meridian II server with MD5 authentication.

  • Page 100: Unix-Like Platforms: Broadcast/Multicast Ntp Client Setup

    MD5 authentication, your Meridian II must have been configured to operate with authentication in the broadcast/multicast mode, and you must know which of the trusted keys it is us- ing for broadcast/multicast operation. The example Meridian II configuration shown in Configuring the NTP Server above will be assumed in the example configuration commands shown here.

  • Page 101: Test Broadcast/Multicast

    Use the command peers to display the NTP peers which your computer is using. One of them should be the Meridian 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 increment.)

  • Page 102: Setting Up Ntp Clients On Windows

    MD5: This method is trickier only because MD5 keys must be set up and distributed accurately to the NTP clients in a secure way. Meridian II is factory configured to authenticate its replies to NTP MD5 clients using its default set of keys.

  • Page 103: Windows: Md5 Authenticated Ntp Client Setup

    Use the command peers to display the NTP peers which your computer is using. One of them should be the Meridian 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 increment.) If you have other peers configured, verify that the offset information for the Meridian II...

  • Page 104: Create The Ntp.keys File

    1 2 Modify the line added previously in Windows: Basic NTP Client Setup so that authentication will be used with the Meridian II server using one of the trusted keys, in this case, key # 1: server 192.168.1.120 key 1 Restart to have it begin using the Meridian II server with MD5 authentication.

  • Page 105: Windows: Broadcast/Multicast Ntp Client Setup

    Use the command peers to display the NTP peers which your computer is using. One of them should be the Meridian 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 increment.)

  • Page 106: Configure Ntp Client For Multicast

    192.168.1.120 key 1 Configure NTP Client for Multicast You must edit the ntp.conf file. Assuming that your Meridian II server has been configured to use key 2 for broadcast authentication as shown in the example in Configuring the NTP Server above, make sure that key 2 is included in the line, and add this line to the end of the ntp.conf file:...
  • Page 107 Use the command peers to display the NTP peers which your computer is using. One of them should be the Meridian 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 increment.)
  • Page 108 C H A P T E R S E V E N This page intentionally left blank. M e r i d i a n I I U s e r M a n u a l...

  • Page 109: Ipv6 Capabilities

    Chapter IPv6 Information The Meridian II Precision TimeBase supports IPv6 out-of-the-box with a modern version 3.2.2 Linux kernel. During network configuration, you have the option to disable IPv6 on either or both Ethernet ports. The IPv6 addressing scheme will see expanding deployment in the near future due to the fact that there are no longer any IPV4 addresses to be allocated in many regions of the world.

  • Page 110: Ipv4-Only Protocols

    IPv6 addresses. Refer to the NTP documentation for details on the directive. interface IPv4-Only Protocols There are several protocols running on Meridian II which are not IPv6 capable: (client and telnet server), .

  • Page 111: About Ptp

    Optional Precision Time Protocol (PTP/IEEE-1588) This chapter contains the configuration and status information for the optional Precision Time Pro- tocol. PTP version 2 is supported. The PTP protocol running on Meridian II is a full Grandmaster Clock (default profile) implementation of the IEEE-1588-2008 standard.

  • Page 112: Ptp Configuration And Status

    Read Appendix I - Software Options if you need information on how to install a software option. Default PTP Configuration Settings The default PTP configuration settings in Meridian II are shown below. If you need to modify these settings then you will need to reconfigure the PTP Subsystem. Default PTP settings are:...

  • Page 113: Ptp Configuration Using The Network Or Serial Port

    PTP Configuration Using the Network or Serial Port command starts an interactive shell script that will allow you to ptpconfig0 ptpconfig1 configure the PTP Subsystem of Meridian II. You will be prompted to set PTP parameters as follows: ETH Port: 0 or 1 Sync Interval (Per Second):...

  • Page 114: Ptp Status Using The Network Or Serial Port

    C H A P T E R N I N E Set the PTP Priority2 value (0-255) 128 ---PTP Delay Mechanism E2E or P2P Set the PTP Delay Mechanism (E2E or P2P) P2P ---PTP Domain Configuration Set the PTP Domain value (0-255) 0 ---PTP Time Mode Configuration Set the PTP Time Mode (UTC or PTP) PTP ---PTP TTL Configuration...

  • Page 115: Ptp Operation

    PTP transmission mode, either MULTICAST or HYBRID PTP Operation The Meridian II is configured as an IEEE-1588 Grandmaster Clock (default profile). Verify that the network settings have been configured and tested using . Once the network has been netconfig configured, the Meridian II will begin to transmit PTP Sync messages after it is locked.
  • Page 116 C H A P T E R N I N E NOTE If using a single Grandmaster, keep the default setting of 128 for Priority 1 and Priority 2. If using two redundant Grandmasters, then you can configure the preferred clock by setting Priority 1 to 127 and Prior- ity 2 to 128.

  • Page 117: About The Ptp Second And Utc Time

    P T P / I E E E - 1 5 8 8 250us Clock is synchronized or in holdover, PTP clock < 250 microseconds Clock is synchronized or in holdover, PTP clock < 1 millisecond 2.5ms Clock is synchronized or in holdover, PTP clock < 2.5 milliseconds 10ms Clock is synchronized or in holdover, PTP clock <...

  • Page 118: Multiport Ptp

    C H A P T E R N I N E Multiport PTP When only one PTP option is enabled it will be configured for PTP Domain 0. If a second PTP eth0 option is enabled then it will be configured for PTP Domain 1.

  • Page 119: Chapter Ten - Rear-Panel Inputs/Outputs (I/O)

    1U chassis and 2U chassis. Your Meridian II provides five option module slots as well as a spare BNC on the CPU module to support up to 23 time and frequency outputs in the 1U chassis and 36 outputs in the 2U chassis. In addition, AC and DC power supplies are available that can be configured in a high-reliability, dual- redundant configuration.

  • Page 120: Serial I/O Port

    The 1 PPS is a “system signal”. This means that there is one 1 PPS signal that affects the whole sys- tem. In other words, if your Meridian II has multiple 1 PPS outputs and you change the pulse width, then all 1 PPS outputs will be affected.

  • Page 121: Time Code Output

    Time Code is a “system signal”. This means that there is one Time Code signal that affects the whole system. In other words, if your Meridian II has multiple Time Code outputs (AM and/or DC) and you change the Time Code format, then all Time Code outputs will be affected.

  • Page 122: Programmable Pulse Output (Ppo) Option

    C H A P T E R T E N C PU MODUL E EX AM P L E ( 1 U ) O NE O PTI O N A L ������ O UTP UT AVA I L AB L E �������...

  • Page 123: Trigger Ppo Function

    R E A R - P A N E L I / O Or, you can use these console port commands: Command: cpuio MeridianII reply: PROGRAMMABLE PULSE OUTPUT is Installed Current Setting = OFF Command: cpuioconfig MeridianII reply: Interactive script is started so you can change the pulse rate. Trigger PPO Function When the PPO option is installed on the CPU Module, then the command is available...

  • Page 124: Direct Digital Synthesizer (Dds) Option

    The DDS is a “system signal”. This means that there is one DDS signal that affects the whole sys- tem. In other words, if your Meridian II has multiple DDS outputs and you change the pulse rate, then all DDS outputs will be affected.

  • Page 125: View The 10 Mpps Output Connector

    The Serial Time is a “system signal”. This means that there is one Serial Time signal that affects the whole system. In other words, if your Meridian II has multiple Serial Time outputs, and you change the settings, then all Serial Time outputs will be affected.

  • Page 126: View The Serial Time Connector

    C H A P T E R T E N View the Serial Time Connector On the front-panel display traverse to the 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 I/O-A, I/O-B or I/O-C) to see which signal is installed.

  • Page 127: Truetime Format

    The time contained in this string depends on the time mode of Meridian II. For example, if you want the time in this string to be UTC, then set the time mode of Meridian II to UTC. (You can do this by...

  • Page 128: Nena Format

    C H A P T E R T E N is the Time Figure of Merit character described in Appendix A - TFOM. This is the on-time character, transmitted during the first millisecond of each second. YYYY is the year is the day-of-year is the colon character (0x3A) is the hour of the day...

  • Page 129: Nmea Format

    Meridian II conform to NMEA-0183 Specification Version 3.01 and are GGA, GLL, GSA, RMC, VTG and ZDA. Your Meridian II can output one, two, or three of these sentences per second. Not all information defined in the NMEA sentences is available from the GPS Receiver resident in Meridian II.
  • Page 130 “on-time” character. Once the unit is locked to GPS, the “on-time” character starts transmitting within the first 20 microseconds of each second.. GGA (GPS Fix Data) The GGA sentence contains the time, position, and fix related data. (EndRun does not calculate mean sea level.) Examples are below: $GPGGA,,,,,,,0,00,,,M,,,*2B<CR><LF>...
  • Page 131 R E A R - P A N E L I / O GSA (GPS DOP and Active Satellites) The GSA sentence identifies the GPS position fix mode, the Satellite Vehicles (SVs) used for navi- gation, and the Dilution of Precision (DOP) values. DOP is an indication of the effect of satellite geometry on the accuracy of the fix.
  • Page 132 The ZDA sentence identifies the time associated with the current 1 PPS pulse. Each sentence is transmitted within 500 milliseconds after the 1 PPS pulse is output and tells the time of the pulse that just occurred. If Meridian II is unsynchronized then this sentence will be composed of null fields. Examples are below: $GPZDA,,,,,,*48<CR><LF>...

  • Page 133: Plug-In Module Options

    R E A R - P A N E L I / O Plug-In Module Options Your Meridian II is supplied with five option slots that can be configured with a variety of plug-in modules. Most of these modules can be added to Meridian II as “plug-and-play” options without hardware or software modification.

  • Page 134: Digital Output Module

    ALL time code outputs in Meridian II. Digital Output Module - Direct Digital Synthesizer (DDS) Programmable synthesized pulse rates from 1 PPS to 10 MPPS in 1 PPS steps are available, includ- ing 1.544 MPPS or 2.048 MPPS.

  • Page 135: Digital Output Module - 1 Pps Or 10 Mpps

    R E A R - P A N E L I / O you change the rate selection, it affects ALL DDS outputs in Meridian II. (This module may not be field-installable, depending on whether your Meridian already has a DDS installed.) Digital Output Module - 1 PPS or 10 MPPS This module provides four copies of either a 1 PPS or a 10 MPPS on-time rate output.

  • Page 136: Sine Wave Module

    ������������ Direct Digital Synthesizer (DDS) Sine Wave Module The DDS Sine Wave Module is an option that adds four frequency outputs to your Meridian II. This module produces a sine wave that is generated from the system DDS. Programmable synthesized...

  • Page 137: Telecom Clock Module

    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 option. When Meridian II is configured with any of the available oscillator upgrades, it can operate as a Primary Reference Clock, providing high-stability Building Integrated Timing Supply (BITS) clock signals directly to digital equipment.

  • Page 138: User Settings

    C H A P T E R T E N TEL EC OM CL OC K M OD UL E ��������� ���������������������������������� ���������� ���������� User Settings There are user settings associated with the T1, J1, E1 and Composite Clock outputs. There are no user settings for the optional Alarm Output.
  • Page 139 R E A R - P A N E L I / O �� ���� �������� �� ����� ������ � ���������� ������ ���������� ���� �������� ����� ������ ������ ������ ������������� ����� ����� ������� ��� ����� ��� ������� �������� ���� ��� ��� ���...

  • Page 140: Alarms

    This level is factory configured and not user settable. If Meridian II loses GPS signal lock then it will drift at a rate dependent upon the installed oscillator. When it has drifted more than 1 microsecond the MTIE fault will be set and a Major Alarm will oc- cur.

  • Page 141: Connectors And Cables

    R E A R - P A N E L I / 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 com- patible with 100-133 ohm twisted pair.
  • Page 142 Connection to RJ48C BITS Clock Input A crossover cable, as shown above, would be used to connect the EndRun Technologies clock buf- fer output on RJ48C pins 4 and 5 to equipment with the BITS clock input on RJ48C pins 1 and 2.

  • Page 143: A Cesium Control Module

    Meridian II, in the same way that the other optional oscillators (OCXO, Rubidium, etc.) operate. The Meridian II sends commands to the 5071A to steer its frequency, monitor its health and set the time-of-day clock on its front panel. The 5071A Operation Status and Questionable Data registers are monitored to determine the overall functional state of the 5071A, and critical 5071A internal diagnostic parameters are also monitored.

  • Page 144: Theory Of Operation

    5071A is no different than the other optional oscillators which might be installed inside the chassis of the Meridian II.) The GPS receiver module inside of the Meridian II has the ability to phaselock its internal oscillator to an external oscillator. This provides the most accurate and stable means of measuring the phase of the 5071A versus GPS and ultimately UTC(USNO).

  • Page 145: Operation

    Warm-Up state until the 5071A has warmed up and is indicating NORMAL operation in the Operation status register. At this time, the Meridian II will transition to the Acquire state and remain there until satellites are tracked, at which point it will begin the normal GPS synchronization and frequency locking process.

  • Page 146: Cesium Status Using The Console Port

    C H A P T E R T E N value. During this settling period, the stability of the 5071A with Option 001 High Performance beam tube may be slightly degraded as the shorter term GPS system noise may not be sufficiently filtered.

  • Page 147: Faults

    Osc Control +3.46 % of maximum Faults A 5071A alarm will show on the Meridian II if any of these conditions occur on the 5071A: Operation Status - STANDBY or FATAL Questionable Data - FREQUENCY or PHASE. COMM_FAULT For information on the Meridian II faults, see Appendix G - System Faults.

  • Page 148: Power Supply Options

    C H A P T E R T E N Power Supply Options Your Meridian II can be configured with several optional power supply inputs which are listed in Appendix K - Specifications, Optional DC Power Inputs. Dual-redundant power supplies are also available.

  • Page 149: Masking Dual Power Supply Fault Alarms

    A fault detector monitors the status of each redundant power supply. When a fault is detected it will trigger a system alarm. When Meridian II is configured with Dual Power Supplies, an alarm will show if the primary or secondary supply does not have power connected.
  • Page 150 Meridian II Precision TimeBase / Tycho II Precision TimeBase This is the option module installation guide for Meridian II and Tycho II. Option modules are installed in slots 1 through 5. Referring to Figure 1 below, the CPU Module is left-most. Next is option slot 1, shown with four BNCs. Slots 2 and 3 are shown with single-slot filler panels, while slots 4 and 5 have a double-slot filler panel installed.

  • Page 151: About Rtic

    The GPS code modulation and carrier phase delays are affected differently as they propagate through the ionosphere. By recognizing a few other aspects of this behavior, EndRun developed the RTIC algorithm to directly quantify the delay through the ionosphere, and resolve the code phase and car- rier phase bias.

  • Page 152: Performance Verified At National Institute Of Standards And Technology (Nist)

    Performance Verified at National Institute of Standards and Technology (NIST) To characterize the performance gain of the RTIC Option, a Meridian II was sent to NIST in May of 2016, where its 1PPS output was monitored continuously relative to UTC(NIST) for over 30 days.

  • Page 153: Rtic Configuration And Status

    Command: installed_sw_opts Meridian 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.

  • Page 154: Rtic Configuration And Status Using The Network Or Serial Port

    C H A P T E R E L E V E N RTIC Configuration and Status Using the Network or Serial Port The commands listed below allow you to get the current RTIC status and turn RTIC on or off. ionostat This command shows parameters associated with the RTIC Option.

  • Page 155: Rtic Performance Plots Using The Http Interface

    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 Plots Page as shown below: M e r i d i a n I I U s e r M a n u a l...

  • Page 156: Rtic Stability Specifications

    C H A P T E R E L E V E N RTIC Stability Specifications The specifications below supercede the 1PPS Stability specification and the System Oscillator Stabil- ity Table shown in Appendix K - Specifications. 1PPS Stability (RTIC Option): TDEV < 2 ns @ τ < 10 seconds, σ...

  • Page 157: Display Description

    Chapter Front-Panel Keypad and Display This section describes the Meridian II front-panel user interface which consists of a graphic vacuum- fluorescent display (VFD) and keypad. The keypad and display provide a convenient interface that allows you to quickly check the operation of the instrument and set up many control parameters. If desired, you can disable the keypad EDIT key to prevent unauthorized tampering.

  • Page 158: Display And Keypad Operation

    Faults Network Clock Display Firmware About Statistics Menu Menu Menu Menu Menu Menu* Menu Setup Information EndRun Clock Menu Time Mode Local Offset Hours Display DST Setup Setup Format Setup NTP Menu I/O Statistics Broadcast/Multicast Status Setup Network Menu Network...

  • Page 159: Keypad Edit Lockout

    F R O N T - P A N E L K E Y P A D A N D D I S P L A Y Keypad EDIT Lockout As a security feature, you can disable all editing processes done through the front-panel keypad. Do this to prevent unauthorized modification of the instrument.

  • Page 160: Main Menu

    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 displays shows measured CPU parameters such as: temperature, free memory, and load average.

  • Page 161: Receiver: Satellite Vehicle Information (Sv_Info)

    F R O N T - P A N E L K E Y P A D A N D D I S P L A Y TFOM: This is a value between 3 and 9 and indicates clock accuracy. A detailed explanation of TFOM is in Appendix A - TFOM.

  • Page 162: Receiver: Last Fix Position (Last_Fix)

    C H A P T E R T W E L V E FLASH and will be restored after a power outage. After position has been determined, the instrument can achieve time lock with only one satellite. In some situations, visibility of the sky is limited and the unit may not be able to determine its posi- tion.

  • Page 163: Receiver: Oscillator Status (Osc_Stat)

    Calibrate is used to compensate for the propagation delay 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 Receiver for more details.

  • Page 164: Faults: Receiver

    C H A P T E R T W E L V E System Oscillator PLL GPS Antenna Option Module System Power/Configuration SECPS Secondary Power Supply (option) PRIPS Primary Power Supply (option) 5071A 5071A Module (option) Faults: Receiver All GPS Receiver faults are shown on this display and their current status, either OK or FAULT. When a fault condition exists the FLT indicator will flash.

  • Page 165: I/O Menu

    If your Meridian II is a 2U chassis with dual power supplies, then the display will show two addi- tional option cards (6 and 7). Refer to Chapter 10 - Rear-Panel I/O for more information regarding the various option modules.

  • Page 166: Network: Reboot

    C H A P T E R T W E L V E Network: REBOOT This is a way to reboot the Meridian II and is necessary after you’ve finished configuring the network parameters. Until you do this, the network parameters that are shown will be the active settings, NOT the new settings.

  • Page 167: Ptp Menu (Optional)

    F R O N T - P A N E L K E Y P A D A N D D I S P L A Y perform a more complete broadcast/multicast configuration via a session or the local telnet RS-232 console using the utility.

  • Page 168: Clock: Hour Mode

    GPS Receiver, the GPS Subsystem and the Linux Subsystem (Linux Root File System and Linux Kernel). The serial number of the Meridian II is also shown. Use UP and DOWN to toggle between the information windows.

  • Page 169: Appendix A - Time Figure Of Merit (Tfom)

    > 10 ms, unsynchronized state if never locked to GPS In all cases, the Meridian II reports this value as accurately as possible, even during periods of GPS signal outage where the Meridian II is unable to directly measure the relationship of its timing outputs to UTC.
  • Page 170 A P P E N D I X A This page intentionally left blank. M e r i d i a n I I U s e r M a n u a l...

  • Page 171: Upgrade Via The Https Interface

    FTP server at endruntechnologies.com to temporary locations on the Meridian II. You will need to enter “root” as the user name and enter root’s password. Then follow the prompts from the HTTPS interface to complete each upgrade as needed.
  • Page 172 A P P E N D I X B 2. If your Meridian II does not have access to the Internet, you must first download the appropriate file(s) from the EndRun Technologies website to the computer that you will be using later to access the Meridian II via its HTTPS interface.

  • Page 173: Upgrade Via The Console Port

    First you need to download the Linux RFS 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.
  • Page 174 Finally, reboot the system by issuing this command at the shell prompt: reboot Wait about 90 seconds for the system to shutdown and reboot. Then log in to the Meridian II using . If all has gone well, you should be able to log in the usual way. After you have telnet entered your password, the system version message will be displayed.

  • Page 175: Recovering From A Failed Rfs Upgrade

    Recovering from a Failed RFS Upgrade To restore your Meridian II to a bootable state using the factory root file system, you must use the serial I/O port and reboot the Meridian II by cycling the power. Refer to Chapter 2 – Basic Instal- lation, Connect the Serial I/O Port and Test the Serial I/O Port for setup details.

  • Page 176: Recovering From A Failed Kernel Upgrade

    Wait about 90 seconds for the system to shutdown and reboot. Then log in to the Meridian II using . If all has gone well, you should be able to log in the usual way. You can check the...

  • Page 177: Performing The Gps Subsystem Upgrade

    Receiver, see the section below called Performing the GPS Receiver Upgrade. First you need to download the GPS Subsystem 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.

  • Page 178: Problems With The Gps Subsystem Upgrade

    Performing the GPS Subsystem Upgrade. First you need to download the GPS Receiver 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.

  • Page 179: Problems With The Gps Receiver Upgrade

    First you need to download the FPGA image 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 Meridian II using either .
  • Page 180 A P P E N D I X B scp –p 6020-0014-000_02.rbf root@host.your.domain:/tmp/rcvrfpga.rbf Now issue the following command to the Meridian II console to initiate the upload: upgradercvrfpga This command performs the file transfer to the FPGA on the GPS Receiver. You will see a file trans- fer progress message while it is performing the transfer.

  • Page 181: Linux Users

    Chapter 3 - Console Port Control and Status. How- ever, the Meridian II does support a subset of the standard Linux commands and utilities and it uses shell, which is the Linux standard, full-featured shell. Very brief descriptions of some of the bash most useful Linux information is described in this appendix.

  • Page 182: Change Password

    NTP Monitoring and Troubleshooting The following command displays which NTP clients are reaching the NTP daemon running on the Meridian II. It will not try to look up host names. ntpq -n -c mrulist A useful command for querying NTP status is the following.

  • Page 183: Text Editors

    Now it is included edit 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 is resident on the system.

  • Page 184: Query And Change Ethernet Ports

    You can redirect syslog files to a remote host (syslog server) by adding the standard Linux redirect commands to the Meridian II’s syslog.conf file. Follow this sequence: 1. Edit /etc/syslog.conf using one of the editors on the previous page. Insert this line: *.* @remote_host...

  • Page 185: Appendix D - Third-Party Software

    "Smarter Timing Solutions" Appendix D Third-Party Software The Meridian II Precision TimeBase is running several different software products created and/or maintained by open source projects. Open source software comes with its own license. These are printed out for your information below.
  • Page 186 A P P E N D I X D For example, if you distribute copies of such a program, whether gratis or for a fee, you must give the recipients all the rights that you have. You must make sure that they, too, receive or can get the source code.
  • Page 187 T H I R D - P A R T Y S O F T W A R E a) You must cause the modified files to carry prominent notices stating that you changed the files and the date of any change. b) You must cause any work that you distribute or publish, that in whole or in part contains or is de- rived from the Program or any part thereof, to be licensed as a whole at no charge to all third parties under the terms of this License.
  • Page 188 A P P E N D I X D The source code for a work means the preferred form of the work for making modifications to it. For an executable work, complete source code means all the source code for all modules it contains, plus any associated interface definition files, plus the scripts used to control compilation and installation of the executable.
  • Page 189 T H I R D - P A R T Y S O F T W A R E reliance on consistent application of that system; it is up to the author/donor to decide if he or she is willing to distribute software through any other system and a licensee cannot impose that choice. This section is intended to make thoroughly clear what is believed to be a consequence of the rest of this License.

  • Page 190: Ntp Software License

    A P P E N D I X D Software License Information about the NTP Project, led by Dr. David Mills, can be found at www.ntp.org. The distribution and usage of the NTP software is allowed, as long as the following copyright notice is included in our documentation: The following copyright notice applies to all files collectively called the Network Time Protocol Ver- sion 4 Distribution.
  • Page 191 T H I R D - P A R T Y S O F T W A R E * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2.

  • Page 192: Ptp Software License

    A P P E N D I X D PTP Software License The PTP/IEEE-1588 option as implemented in the Meridian is covered by patents and copyrights. For patents that pertain to the Std No 1588, see the IEEE Standards Association at http://standards.ieee.org/db/patents/pat1390.html Information about the PTP Project, led by Kendall Correll, can be found at ptpd.sourceforge.net.

  • Page 193: Antenna Location

    "Smarter Timing Solutions" Appendix Installing the GPS Antenna This appendix contains guidelines for installing the GPS antenna. Mounting the antenna with a good view-of-the-sky is very important. A rooftop installation is usually best. The accuracy & stability specifications in Appendix K - Specifications assume an antenna installation with a very good view- of-the-sky.

  • Page 194: Gps Antenna Kit

    A P P E N D I X E GPS Antenna Kit The Meridian II ships with a GPS Antenna Kit which includes 50 feet (15 meters) of antenna cable. This amount of cable is sufficient for the majority of GPS antenna installations. Longer cable runs can also be accommodated.

  • Page 195: Long Cable Runs

    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 installed. For cable lengths less than 700 feet, Belden 9104 is acceptable.

  • Page 196: Using Two Or Three Lnas

    A P P E N D I X E Cable Length Cable Number of Type LNAs Up to 250 feet Belden 9104 (76 meters) or equivalent 251 to 500 feet Belden 9104 (77 to 152 meters) or equivalent 501 to 700 feet Belden 9104 (153 to 213 meters) or equivalent...

  • Page 197: Other Accessories

    This way you will not get a false alarm from the GPS Receiver’s antenna load sensor. However, the Meridian II allows you to mask an antenna fault alarm from causing a system fault by using the command. See details in Chapter 3 - Console Port Control and Status.

  • Page 198: Calibrate Your Receiver

    A P P E N D I X E Calibrate Your Receiver In order for the Meridian II to synchronize with maximum accuracy to UTC, the delay for the cable and all devices between the antenna and the GPS receiver input (i.e. GPS preamplifiers, signal split- ters, lightning arrestors, etc.) must be compensated for.

  • Page 199: Mounting On A Rooftop

    Your Meridian II is capable of operation from either an automatically determined 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 itself or a highly accurate surveyed position.
  • Page 200 A P P E N D I X E ����� ������ ��� ������� ��������� ��� ����� ������ ��� ��������� �������� ������� �� �������� ������ ������� ����� �������� ���� ���� ����� ���� ���� ���� ���� ����� FIG UR E 1 - G PS A N TEN NA RO OF TOP M O UN TIN G H ARDWARE M e r i d i a n I I U s e r M a n u a l...
  • Page 201 I N S T A L L I N G T H E G P S A N T E N N A ���� ������ ���� ���� � ��������� �������� ����������� ����������� ��� ������� ����� ������ ��� ������� ��������� ��� ���...
  • Page 202 A P P E N D I X E This page intentionally left blank. M e r i d i a n I I U s e r M a n u a l...

  • Page 203: Automatic Leap Second Insertion

    Leap Second Insertion Your GPS-synchronized Meridian II precisely adjusts for leap seconds if and when they occur. There is nothing you need to do in order to keep your Meridian II time server accurately synchronized to UTC. You can see the current GPS-UTC parameters that are downloaded from the satellites by using the command.
  • Page 204 A P P E N D I X F This page intentionally left blank. M e r i d i a n I I U s e r M a n u a l...

  • Page 205: Overview

    You may want to mask the ANT fault if you are using a GPS splitter. You may want to mask the SIG fault if you are operating your Meridian II as a Stratum 2 NTP Server and are not using a GPS signal.
  • Page 206 Usually it means that the antenna cable is not plugged into the connector on the rear of the Meridian II. To see whether it is a short or an open check the receiver faults. This fault may also occur when using an antenna signal splitter.

  • Page 207: Receiver Fault Definitions

    GPS Receiver FLASH Writes (FLSH) This fault indicates that the GPS Receiver is unable to verify a write to the FLASH non-volatile parameter storage area. This should not ever occur under normal operation.. Please contact EndRun Customer Support. Synthesizer Limits (SYN1) This fault indicates that the local oscillator synthesizer has reached the alarm limit.
  • Page 208 This fault indicates that the GPS Receiver received an erroneous time input from the GPS signals. If the condition persists please contact EndRun Customer Support. GPS Receiver Oscillator (OSC) This fault indicates that the main 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).

  • Page 209: Irig-B122/002

    Appendix Time Code Formats A standard feature of your Meridian II Precision TimeBase is a single time code output available at the rear panel BNC connector identified as AM CODE. A DC-shift time code is available as an optional output on the CPU Module (see CPU Module Options in Chapter 10 - Optional Rear-Panel Outputs).

  • Page 210: Ieee-1344 Bit Definition

    A P P E N D I X H IEEE-1344 Bit Definition Bit Position Bit Definition Explanation Year, BCD1 Unit years Year, BCD2 Year, BCD4 Year, BCD8 Not used Year, BCD10 Tens years Year, BCD20 Year, BCD40 Year, BCD80 Position identifier Leap second pending Set to one, 59 seconds prior to leap insertion Leap second...

  • Page 211: Wrt_Sw_Opt

    In other words, you can enable a software option yourself, after you have received your Meridian II. First you must obtain an 8-digit license key from EndRun Technologies, then you can enable it using the command.

  • Page 212: Software Option Bit Definitions

    A P P E N D I X I Software Option Bit Definitions Bits are numbered from 0 to 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).

  • Page 213: Appendix J - Operation With A Gps Simulator

    GPS-based timing systems supporting critical infrastructure functions could be vulnerable to mal- function due to weak signals, jamming, spoofing or accidental GPS control system errors. EndRun Technologies’ GPS timing receiver technology has evolved to be highly robust against these threats.

  • Page 214: Resetlastgpswn

    GPS receiver firmware will be used as the Last GPS Week Number. This Last GPS Week Number is the minimum possible full GPS week number. The Meridian II will never allow the date and time to be set prior to the date and time corresponding to this Last GPS Week Number.
  • Page 215 S I M U L A T O R U S E are compared to a historical record of previous UTC leap seconds and the GPS week numbers at which they were inserted into the UTC timescale. Should a simulator be set with arbitrary values for these UTC leap seconds that differ by more than a couple of seconds from the actual values currently being transmitted by the GPS, the almanac data will be rejected.
  • Page 216 A P P E N D I X J M e r i d i a n I I U s e r M a n u a l...

  • Page 217: Appendix K - Specifications

    "Smarter Timing Solutions" Appendix K Specifications The following accuracy and stability specifications assume a stationary position (not dynamic mode), four satellite lock, and the antenna mounted with a full view-of-the-sky. GPS Receiver: L1 Band – 1575.42 MHz. 12 Channels, C/A Code (16 correlators). Static mode and dynamic-platform mode (shipboard only).
  • Page 218 A P P E N D I X K System Status LEDs: Sync LED: Amber LED pulses to indicate GPS acquisition and lock status. Alarm LED: Red LED indicates a fault condition. Network I/O: Two rear-panel RJ-45 jacks. 10/100/1000Base-T Ethernet. Two LEDs on each port indicate speed and activity.
  • Page 219 To connect to a computer, a null-modem adapter must be used. The serial cable provided with the shipment is wired as a null-modem. Pinout for the RS-232 console port is shown below. Note: For operational details see Chapter 3 - Console Port Control and Status. Meridian II DB9M Pin Signal Name Not Connected...
  • Page 220 A P P E N D I X K Size: 1U Chassis (AC power): 1.75”H x 17.15”W x 11.2”D. 19” rackmount. 1U Chassis (DC power): 1.75”H x 17.15”W x 11.8”D. 19” rackmount. 1U Weight: < 8 lb. (3.6 kg.) 2U Chassis (AC power): 3.5”H x 17.15”W x 11.2”D.

  • Page 221: System Oscillator

    S P E C I F I C A T I O N S System Oscillator TCXO: Temp Stability: 2.5x10 over -20º to 70º C. Ageing Rate/Year: 1x10 NTP Stratum 1 Holdover: 24 hours. Optional Medium-Stability OCXO (MS-OCXO): Temp Stability: 4x10 over 0º...
  • Page 222 A P P E N D I X K System Oscillator Phase Noise Table (dBc/Hz @ 10 MHz): TCXO Spurs -100 -100 -125 -100 -135 -100 -140 -100 100k -145 -120 Ηz MS-OCXO HS-OCXO US-OCXO Spurs -105 -113 -120 -130 -138 -120 -135...

  • Page 223: Power Supply Options

    S P E C I F I C A T I O N S Power Supply Options Optional DC Power Input (1U): 12 VDC (10-20 VDC), 6.0A maximum. 24 VDC (19-36 VDC), 3.0A maximum. 48 VDC (37-76 VDC), 2.0A maximum. 125 VDC (70-160 VDC), 1.0A maximum.

  • Page 224: Cpu Module Options

    A P P E N D I X K CPU Module Options Optional 1 PPS (RS-422) Output (CPU Module): Signal: RS-422 levels. RS-422 (100Ω differential): V (min)=2.1V, V (nom)=2.4V, V (max)=3.0V, DIFF DIFF DIFF (max)=3.3V referenced to GND. User-Selectable Width: 20 us, 1 ms, 100 ms, 500 ms. User Calibration: +/- 500 us, 1 ns resolution.
  • Page 225 Baud Rate: User Selectable to 4800, 9600, 19200 or 57600. Parity: User Selectable to Odd, Even or None. ASCII Formats: User-Selectable to Sysplex, EndRun, EndRunX, Truetime, NENA or NMEA. Accuracy: The “on-time” characters starts transmitting within the first 20 microsecs of each second.

  • Page 226: Plug-In Module Options

    A P P E N D I X K Plug-In Module Options Optional Low Phase Noise Module: Quantity: 4 outputs (1U or 2U chassis) or 6 outputs (2U chassis only). Οutput Frequency: 5 MHz or 10 MHz. Οutput Level: +13 dBm, +/- 2 dBm at 50Ω. Harmonics: <...
  • Page 227 S P E C I F I C A T I O N S Optional Analog Time Code Output Module: Quantity: 4 outputs. Drive: 1 V into 50Ω. Frequency: 1 kHz. Alignment: Within 5 us of 1 PPS. User-Selectable Formats: IRIG-B (122, 123, IEEE-1344 compliant), NASA-36, and 2137. Connector: Rear-panel BNC jack.
  • Page 228 Quantity: 0, 1 or 2. Type: Transformer-coupled complementary-pair via 2xRJ48C. Single-ended via 2xBNC. Frequency: 64 kbps. Synchronization: Phase locked to the Meridian II TimeBase 10 MHz. Data Format: All ones. User-selectable bipolar violation (BPV). Line Z: 110Ω nominal (complementary pair), or 75Ω nominal (single-ended).
  • Page 229 Quantity: 0, 1 or 2. Type: Transformer-coupled complementary-pair. Frequency: 1.544 Mbps. Synchronization: Phase locked to the Meridian II TimeBase 10 MHz. Data Format: All ones. User-selectable for Unframed, D4 SuperFrame (SF) or CRC6 Extended SuperFrame (ESF). Line Z: 100Ω nominal.

  • Page 230: Compliance

    ICES-003 A, Issue 5 FCC Part 15 Subpart B Sections 15.107 and 15.109 Data subject to change. EndRun Technologies may make changes to specifications and product descriptions at any time, without notice. M e r i d i a n I I U s e r M a n u a l...
  • Page 231 �� � � � ������� � � � ��������� �� � �� � ���� � ���� ������������ ������������� EndRun EndRun EndRun EndRun TEC HNO LO GI ES TEC HNO LO GI ES TEC HNO LO GI ES TEC HNO LO GI ES �����������...
  • Page 232 �������� ������ �� �� ������� �� ���������� �� ���������� �� ���������� ����� ����� � ���� ����� ��� EndRun EndRun EndRun EndRun TECHNOLOGIES TECHNOLOGIES TECHNOLOGIES TECHNOLOGIES � � � � � � � � � � � � � �� �� ����� �� �����������������������������������...
  • Page 233 �� � � � ������� � � � ��������� �� � � �� � � ���� � ���� � ���� ������������� EndRun EndRun EndRun EndRun TEC HNO LO GI ES TEC HNO LO GI ES TEC HNO LO GI ES TEC HNO LO GI ES �����������...
  • Page 234 � � � ��������� �� � � � ������� � � � ��������� �� � � �� � � ���� ������������� EndRun EndRun EndRun EndRun TEC HNO LO GI ES TEC HNO LO GI ES TEC HNO LO GI ES TEC HNO LO GI ES �����������...
  • Page 235 S P E C I F I C A T I O N S �������������������������� ��������������������������������������������� �������������������� ������������������������ ����������������������� ������������������������������������������������������������� ��������������������������� ������������� �������������������� ������������� ������������������������������������������������ � ��������������������������������������������������� � ����������������������������������������������� � ����������������������������������������������� ������������������������������������������� ��������������������������������������������� ���������������������������������������� �������������������������������� � � �������������������������������� � � ��������������������������������...
  • Page 236 A P P E N D I X K M e r i d i a n I I U s e r M a n u a l...

  • Page 237: Special Modifications - Changes For Customer Requirements

    "Smarter Timing Solutions" Special Modifications 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 modified then this section will describe what those changes are.
  • Page 238 S P E C I A L M O D I F I C A T I O N S This page intentionally left blank. M e r i d i a n I I U s e r M a n u a l...
  • Page 240 2270 Northpoint Parkway Santa Rosa, CA 95407 TEL 1-877-749-3878 FAX 707-573-8619 "Smarter Timing Solutions" www.endruntechnologies.com...

Table of Contents