NTS-4000-S GPS NTP Time Server For Accurate Time. Reference Manual

Transcription

1 NTS-4000-S GPS NTP Time Server For Accurate Time Reference Manual 1

2 Index Index 2 Introduction 3 Features 3 Package Contents 4 GPS Receiver Enclosed in an IP65 Weather Proof Box 4 Wiring requirements for NTS Hardware Installation 7 Wire Length 8 Frequently Asked Questions 9-10 Server Location 11 Connect to Network 11 Install the Antenna 11 Connecting Server to Antenna 11 Configuration 12 Configuring the Server 13 Install Windows Based Configuration Program 14 Network Configuration 18 Time Server Configuration Options 20 Search 21 Broadcast Search 21 Search by IP 21 Debug 21 Upgrade Firmware 21 Client Configuration 22 Timesync 22 K9 23 Windows XP 23 Linux/Unix 23 Time Server Fundamentals 24 2

3 Introduction The NTS-4000 timeserver provides the correct time to computers on a local area network (LAN). Correct time is derived from either Global Positioning Satellites (GPS), or radio-based broadcasts from Cumbria in the UK (MSF), Frankfurt in Europe (DCF77), and Fort Collins, Colorado in the US (WWVB). Once installed on a computer network the NTS-4000 provides a server for the Network Time Protocol (NTP). Each PC on the network can retrieve the time from the server using a NTP client. The NTS Time Server provides a bridge between Ethernet wired LANs and GPS and radio based time sources. Features Hardware clock support Interfaces directly to 10/100Mbps IEEE Ethernet networks Firmware is stored in flash memory and can be upgraded Windows based configuration program Power and network activity LED indicators Optional dual external antennas supporting diversity NTS 4000-S 3

4 Installation Package Contents Before installing the unit, first locate the following parts: NTS-4000 Time Server GPS Antenna unit and power supply IEC Power Cables and power connector Time Server unit NTS 4000-S Separate power supply There is a junction box on the rear of the unit (In the MSF unit the junction box uses four-core cable, in the GPS version, six-core cable is used). The unit is powered by an IEC cable, its operating voltages are between 100v and 240v (0.8amp). GPS Receiver Enclosed in an IP65 Weather Proof Box The cable used for the antenna is six-core unscreened alarm cable; this can be purchased from Galleon Systems or from a local electrical retailer. 4

5 Wiring Requirement for the NTS

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7 Hardware Installation The following diagram summarises the hardware configuration. GPS Clock Installation 7

8 Wire Length When cutting the wires to set up the 15 way D-type connector we advise you not to cut the wires too far back as this can cause a possible shortening to the system or the antenna. See below for a picture guide on how much we recommend you cut off: 8

9 Frequently Asked Questions Q: What do the three LED s on the front of the display mean? A: The A LED represents that there is power going to the Unit, the B LED is the GPS Signal and the C is the MSF/WWVB/DCF Signal Either of these or both if you have a Dual unit will be flashing showing you that the unit is picking up the signal from the respective antenna Q: How do you use the software to program the unit? A: After installing the software on you PC double click on the config software program the program will load up and identify the unit connected double click on the unit and will bring up a Configuration pop up box which will show you the IP address, netmask, gateway and IP mode this IP mode can be changed from DHCP to Static IP. Click on ok and the unit is now programmed. Q: How do you use the software to debug the unit? A: The software has on the top section a debug button this will pop out a window like cmd prompt window this will then start showing data from the unit and you can read any error messages that are coming from the Unit, we also recommend that you check all cabling to the unit as this might also be a cause to errors in the unit 9

10 Q: The GPS unit cannot pick up the signal - what can be done to improve this? A: The ideal location for the GPS antenna is the roof of the building as the Antenna needs to get the best possible chance to receive the signal from the satellites Q: Can the cabling for the antenna be taken across the existing CAT5 cabling structure in our building? A: Yes, the GPS antenna can be taken across CAT5 / UTP cabling however the cabling must be point to point and cannot pass through routers, hubs or switches. Q: What type of cable should I use for extending the GPS antenna to 1000 metres? A: The GPS antenna uses standard unscreened four-core cable; in most cases this is adequate however in some cases screen cable may be required. Note: The cabling is referred to as six-core alarm cable 10

11 Server Location Choose a suitable location for the NTS-4000; please bear in mind you will need to run a cable from this location preferably to the roof of the building or to a window. Connect to Network Connect the NTS-4000 to the network using a standard RJ45 cable. Install antenna Locate a mains power supply on the roof of the building or a mains power supply that can be accessed from the roof. Choose an area to mount the GPS antenna; the ideal place would be the roof of the Building. Things to avoid are air conditioning units and power distribution units, as these will cause electrical interference. Connecting the server to the antenna The cable should be run from the rack mount enclosure to the selected mounting position Hint: It is a good idea to leave some slack cable in case you need to move the unit later. Note: The maximum cable length is 1000 metres (1 KM). 11

12 Display and system start-up Configuration First power the GPS antenna then power up the NTS The LCD display should show the following information: Current time (when synchronised) IP address of the Ethernet port The synchronisation state of the system When the system starts, it will initially display a message: GPS xxxxxx, Radio Pulse x, IP xxx.xxx.xxx.xxx Unsynchronised This indicates that the system is searching for an initial timestamp from the antenna. Once this is achieved, the system sets its internal clock using the accurate time data. After power is applied, the server should be able to provide correct time within a few minutes of the correct clock operation. The delay is due to the NTS-4000 locating and synchronising to the time signal. Note: The display will show GPS xxxxx and Radio Pulse xxx whether one or both types of antenna are connected. The GPS message will show whether GPS data is received and if a fix has been achieved. The Radio clock messages shows if pulses are being receive, typically this value should change once every second, if the value changes intermittently or not at all, the radio antenna may need to be repositioned. Once synchronised the display should change to: Synchronised to xxx, IP xxx.xxx.xxx.xxx yyyy/mm/dd hh:mm:ss Once synchronised the system can tolerate the loss of signal for 30 minutes before it becomes unsynchronized, once synchronised and calibrated (approximately 30 minutes after the first time the NTS-4000 was synchronised after it was switched on) the system can tolerate the loss of signal for 14 days before it becomes unsynchronised. 12

13 Configuring the Server Once the hardware has been installed, follow these steps to configure the server for use: Install the Windows configuration program Configure the network Configure the NTP options Note: The time displayed is UTC. It may not match your wall clock depending on what time zone you are in and whether daylight savings/summer time is in effect. This does not affect whether the correct time is shown on client PCs. Clients use the time in UTC from the server plus information about their local time zone to calculate the correct local time. Note: The time displayed is accurate to the nearest second, updated once a second. This means that the display may appear to be up to a ½ second off from other time sources. The display does not reflect the underlying system s ability to provide the correct time to millisecond accuracy. 13

14 Install Windows based Configuration program Now you need to install and run the Windows based configuration program to set up the network connection, you will then be able to configure NTP clients to use the NTS Run the setup program (called ConfigVxx.exe where xx is the version number) on a suitable Windows PC - all recent versions of Windows are supported.. ` Press Next Press Next 14

15 Select where you would like the program installed Select the program group 15

16 Press Install Press Finish and the configuration program will be started, it will immediately search the network for NTS-4000 Devices. 16

17 Note: You may get a warning from your PC if you have a firewall enabled. e.g. The Configuration program must be unblocked to allow it to work correctly. All the NTS-4000 Devices found are shown along with their current IP address (if any), hardware MAC address and software version number. Select the device you are configuring then press Configuration. 17

18 Network Configuration The first configuration step is to set up the network so other devices can use the NTS The display always shows the currently active IP address for the network connection. Hint: The NTS-4000 must be configured with a valid IP address before the NTP options can be set. First, determine whether you are going to use DHCP (automatic network configuration) or a static address. DHCP is short for Dynamic Host Configuration Protocol, a protocol for assigning dynamic IP addresses to devices on a network. With dynamic addressing, a device can have a different IP address every time it connects to the network. To switch DHCP on to determine network settings automatically Select change Ethernet setting Select IP Mode DHCP This is the easiest way to set up the server initially; however, it is recommended that a static address be assigned to the server, if possible, to fix the address permanently. With automatically assigned addresses using DHCP it is possible that the address could change, possibly requiring client reconfiguration. 18

19 To assign static settings to the network first determine the following: Gateway Subnet mask IP address the server should use These should be available from your network administrator. To switch DHCP off Select change Ethernet setting Select IP Mode Static IP The Gateway, Subnet mask and IP address should be replaced by values for your network. Hint: Once the NTS-4000 is correctly configured, the Windows Configuration program is no longer required for normal operation. 19

20 Time Server Configuration Options To set the timeserver options for the NTS-4000, select the device as before, then press Options. The current status is shown along with the options to send broadcasts and/or syslog messages. Broadcasts are a way of sending a single timestamp to many computers at the same time. Multicasts are similar but may span more than one subnet if the network is set to do so. If the value of the broadcast frequency is set to 0, none are sent. The K9 client uses broadcasts so broadcasts should be switched on when it is used. Broadcasts cover the local subnet but go no further. Up to 10 broadcast addresses may be set. Press the default broadcast and/or default multicast buttons to set the most commonly used addresses. Other subnets may be sent broadcasts (called directed broadcasts). Eg: one could send a broadcast to subnet x using an address of The syslog server is where system status messages are sent using the syslog protocol. If this is set to no syslog messages are ever sent. 20

21 Search The search options are used to find NTS-4000 Devices on the network. Broadcast Search Broadcast search sends a message to all devices on the local subnet. Any that reply are listed. This is done by default when the configuration program starts. Search by IP If you know the address of the NTS-4000 you can search for it directly using this option. It allows access to NTS-4000 Devices beyond the local subnet. Debug Selecting debug will start a telnet session with the NTS-4000 Showing information that may be useful to engineers to resolve problems. 21

22 Upgrade Firmware Upgrade allows the NTS-4000 Software to be upgraded to add new features and/or fix problems. Select the device to be upgraded and press the upgrade button or select Upgrade->firmware. Now select the new firmware file supplied by Galleon Systems and press Open. After approximately 1 minute, the following message should be displayed: The NTS-4000 should restart automatically. Client Configuration The following clients are supported. Others clients that use SNTP or NTP should work too. Add a server of type SNTP/NTP Timesync Enter the address of the NTS

23 K9 For K9 to set the time the NTS-4000 must be set to send broadcasts. This is off by default. On the option page, select a non-zero broadcast frequency. Windows XP Windows XP may be configured to use an NTP time source such as the NTS In the Date and Time control panel select the Internet Time tab and enter the NTS-4000 as the server. Linux/Unix Place an entry in the Linux/Unix machine s ntp.conf file for the NTS Eg server Where the IP address should be that of the NTS This assumes that NTP is already set up on the machine. 23

24 Time Server Fundamentals The NTS-4000 provides a network-based timeserver using the NTP protocol - it may be assigned fixed or dynamic network addresses using DHCP. The Network Time Protocol (NTP) is used to synchronise the time of a computer client or server to another server or reference time source - such as a radio or GPS satellite receiver. It provides accuracies typically within a few milliseconds on LANs and up to a few tens of milliseconds on WANs relative to Coordinated Universal Time (UTC). GPS is a system of satellites, computers, and receivers that is able to determine the Latitude and longitude of a receiver on Earth by calculating the time difference of signals from different satellites to reach the receiver. These signals are generated by an atomic clock and are used by a GPS timeserver to receive the time. UTC (Universal Time Coordinated or Temps Universel Coordonné) is an official standard for the current time. UTC evolved from the former GMT (Greenwich Mean Time), GMT had been adopted as the world's standard time but one of the reasons it has been replaced as official standard time was the fact that it was based on the mean solar time. Newer methods of time measurement showed that the mean solar time varied a lot by itself as the Earth s rotation is varied. The following list will explain the main components of UTC: Universal means that the time can be used everywhere in the world, meaning that it is independent from time zones (i.e. it is not local time). To convert UTC to local time, one would have to add or subtract the local time zone.. Coordinated means that several institutions contribute their estimate of the current time, and UTC is built by combining these estimates - all contributions to UTC are made by atomic clocks. 24