Clock Western
 |
 DeWALT DC011 Heavy Duty Worksite Radio Charger New  US $132.99
|
 NEW 6 SQUARE WALL OR TABLE ROMAN CLOCK CHROME FINISH US $5.39
|
 NEW GORDON RAMSAY PROGRAMMABLE COFFEE MAKER 16045 $109 READ US $5.64
|
 New LIFES BETTER IN THE SADDLE Western Wall Clock RUSTIC Sign Plaque Art US $21.99
|
 New My Heroes Have Always Been Cowboys WESTERN WALL CLOCK Rustic Plaque Sign US $21.99
|
 NEW QHK021KLH Seiko Bell Sound Unofficial Hidden Mickey Mouse Seiko Alarm Clock US $39.99
|
 MicroLux ML4000D Pro Air UV Purifier Hepa Carbon Ionic ML4000DBK US $185.99
|
 MicroLux Air Purifier Hepa Carbon Ionic Ozone ML4000DCH US $185.99
|
 Western Cowboy Boot Table Clock 11x5 Fair Combined Shipping US $17.99
|
 Western Horseshow Wall Clock Boot Cowboy Western Decor 3D Boot Decor US $25.99
|
 Western Cowboy Clock Horse Wall Decor US $25.99
|
 Western Cowboy Horse Silhouette Wagon Wheel Rope bandana lariat Horseshoe Clock US $23.99
|
 Western Horseshoe Horse Shoe Cowboy Boot Lone Star Wall Clock Decor Accent US $24.99
|
 WESTERN LARIAT ROPE CLOCK with loop chicken US $85.00
|
 MicroLux ML4000D Pro Air UV Purifier Hepa Carbon Ionic ML4000DCH US $185.99
|
 NEW DOUBLE SIDED BISTRO HANGING WALL CLOCK 8 US $.18
|
 Western Wall Decor Clock US $10.99
|
 NEW LA CROSSE ATOMIC DIGITAL WALL CLOCK US $3.18
|
 Sale $995 Golden OLD CLOCKS on Wall 45 feet Wallpaper Border 853 US $9.95
|
 MONTANA SILVERSMITHS WESTERN CLOCK US $29.95
|
 Western Horseshoe Wall Clock Unique Handcrafted 1 OF A KIND FREE SHIPPING US $49.00 |
 Western Lodge Cabin Decor Americana Wood Wall Clock US $19.95
|
 Western Lodge Cabin Decor Wild Horses Wood Wall Clock US $15.95
|
 Western Lodge Cabin Decor Simple Peasures Wood Wall Clock US $15.95
|
 Western Lodge Cabin Decor Texas Flag Wood Wall Clock US $16.95
|
 Western Lodge Cabin Decor Rodeo Star Wood Wall Clock US $17.95
|
 Lux Everything 2H 2C Digital Thermostat PSP722E US $70.89
|
 3 WOLVES wolf CLOCK coyote Great unique Mantel DESK CLOCK herco Western Wildlife US $4.99
|
 New WESTERN STAR WALL CLOCK Barn Red Paisley Black Print RUSTIC Decor Accent ART US $21.99
|
 New RODEO WALL CLOCK Western Star Decor TEXAS Bandana US $21.99
|
 Sale$895 Country Clocks Birdhouses 45 feet Wallpaper Border US $9.95
|
 MicroLux Air Purifier Hepa Carbon Ionic Ozone Generator US $169.00
|
 FLEETWOOD MAC Rumours 1977 Recycled Record Vinyl Wall Clock US $28.00
|
 NEW 37921 MOSS EDGED BIRD HOUSE | LOT OF 2 US $21.03
|
 NEW 14401 HOLLY BERRY SCENT CANDLE | LOT OF 2 US $21.97
|
 Solid Brass Good Luck Horse Shoe Horseshoe Decor US $5.97
|
 NEW 12615 PLAYFUL ELEPHANT WINE HOLDER US $21.06
|
 Solar Tracker Controller Electronics Single Axis 12V 30V DC US $34.95
|
 Western Horse Horseshoe Cowboy Shower Curtain Bath Rug Towel Set Decor US $22.99
|
 NEW 31182 ROWBOAT CURIO CABINET US $25.24
|
 Opuntia rufida Clock Face Cactus Perfect Round 1 Pad Cold Hardy US $7.95
|
 14752 SEAFARING WALL CLOCK US $59.95
|
 NEW TS 9786 black TRISONIC BLACK MINI TRAVEL ALARM CLOCK SMALL US $4.31
|
 Clair De Lune Moonlight Glow in the Dark Clock US $33.99
|
 Its 5 Oclock Somewhere metal art piece by HGMW US $17.99
|
 John Deere Essential Neon Clock US $54.99
|
 Western Cowboy Horse Silhouette Wagon Wheel Rope Horseshoe Clock Wall Decor US $22.99
|
 Vintage Handled Cake Serving Plate AUSTRIA Victoria US $24.99
|
 Its 5 Oclock Somewhere Jimmy Buffet Style Parrot windchime by HGMW US $29.99
|
 Edward Meyer™ Grandfather Clock Chimes Beveled Glass US $269.97
|
 COWBOY CLOCK US $24.95
|
 New RFID Reader Access Controller System 10 ID Cards Not Need To Connect The PC US $51.29
|
 THERMASOL Signature Trad Control CHROME SETNTSPC US $760.00
|
 THERMASOL Signature Trad Control SAT NICKEL SETNTSSN US $819.20
|
 MOEN Chateau 1H POSITEMP KNOB T S CHROME T183 US $41.06
|
 VINTAGE4 pc Set CHICKEN CONDIMENT SERVER JELLY JAR BUTTER PLATE hen rooster US $32.99
|
 Western Home Decor Wagon Wheel Cowboy Bandana Wall Clock US $21.99
|
 MOEN Chateau 1H POSITEMP LVR SHR PLH BRASS TL182P US $98.62
|
 NEW BIRD FEEDER copper finish ROUNDABOUT 5 seed Hangs US $111.00
|
 RUSTIC WAGON WHEEL CLOCK WESTERN WALL DECOR NEW US $22.99
|
 RFID Reader Access Controller Keypad And Time Clock Free 10 ID Cards Brand New US $51.29
|
 Single Door Keypad And RFID ID Card Reader Access Control 10 ID Cards US $35.89
|
 NEW CHILLI PEPPER CLOCK WESTERN STYLE US $8.99
|
 Door Access Control Keypad RFID ID Proximity Reader 10 ID 125Khz Cards US $35.89
|
 Global Sync Atomic Clock Chass 190 US $42.98
|
 Western Magazine Bow Tie Metal Sign US $29.95
|
 World Sync Time Zone Map Atomic Clock in Silver Chass US $48.30
|
 Global Sync Atomic Clock in Shiny Yellow Chass 392 US $47.63
|
 Global Sync Atomic Clock in Shiny Green Chass 391 US $47.63
|
 Horse Shoe Clock Table Top Desk Shelf Boots Hat Western Decor US $12.99
|
 Whimsical Dog Dock Wall Clock Bone Pendulum Childs Room Home Decor Collection US $22.79
|
 Creekvine Designs 4 Cedar Classic Porch Swing US $369.99
|
 Creekvine Designs 5 Cedar Classic Porch Swing US $429.99
|
 Creekvine Designs 6 Cedar Classic Porch Swing US $529.99
|
 Creekvine Designs 2 Cedar Classic Porch Swing US $329.99
|
 NEW 32190 TREEHOUSE BIRDHOUSE | LOT OF 2 US $27.30
|
 NEW 60042 LAUREL BRANCH CANDLEHOLDER LANTERN TRIO US $27.97
|
 NEW 37777 LAVENDER 4 OZ ROOM SPRAY | LOT OF 8 US $24.06
|
 NEW 37769 LIFE STYLE INCENSE WITH HOLDER DISPLAY BOX PACK OF 50 US $52.34
|
 NEW 37768 INCENSE STICK DISPLAY PACK OF 48 WITH DISPLAY BOARD US $30.70
|
Atomic Clock Systems
An atomic clock provides an extremely accurate source of time. There are various types of atomic clock, mostly found in laboratories: Caesium Clocks; Hydrogen Clocks; and Rubidium Clocks. Most commercially available atomic clock time synchronisation systems utilise a radio or GPS time signal that is linked to an accurate time reference. In this manner a highly accurate source of time is readily available to everyday users, without the expense of installing highly expensive and complex equipment.
This article provides an overview of atomic clock systems with particular emphasis on their use with NTP server systems for PC and computer network time synchronisation.
Radio Atomic Clock Time References
Radio time transmissions such as the MSF-60 (UK), DCF-77 (Germany) and WWVB (US) time signals broadcast highly accurate time information from a radio transmitter. The time transmissions are derived from an atomic clock time reference, and can be received by timing equipment with a low-cost radio receiver. The MSF-60 radio signal is transmitted from Rugby in the United Kingdom with coverage of the whole of the British Isles and much of North-Western Europe. The DCF-77 time signal is transmitted from Frankfurt, Germany, and covers most of Central Europe. While the WWVB signal is transmitted from Fort Collins, Colorado, USA.
MSF-60 Time Transmission
The MSF-60 time signal is a long wave radio time signal broadcast at 60kHz from Rugby in the UK. The radio signal is maintained by BT Engineering Services. The MSF-60 time signal is generated from extremely accurate atomic clocks located at the National Physics Laboratory (NPL). When decoded, it provides a highly accurate timing reference for NTP servers, reference clocks and other computer timing equipment.
DCF-77 Time Transmission
The DCF-77 time signal is a long-wave radio time signal broadcast at 77.5kHz from Mainflingen, near Frankfurt, Germany. The radio signal is maintained by T-Systems, a sub-division of Deuche Telecom, and has been in operation since 1959. The DCF-77 signal is generated from extremely accurate atomic clocks located at the German National Physics Laboratory. When decoded, it provides a highly accurate timing reference for clocks and computer timing equipment.
WWVB Time Transmission
The WWVB time signal continuously broadcasts time and frequency signals at 60 kHz from Fort Collins, Colorado, USA. The time reference is maintained by the US National Institute of Standards and Technology. WWVB has provided continuous time and frequency broadcasts since 1962. The signal provides a timing reference with an accuracy of less than 100 microseconds.
GPS Atomic Clock Time Reference
The Global Positioning System (GPS) is a US military system for worldwide navigation. The system consists of 24 orbiting satellites, each satellite has a highly accurate atomic clock on-board synchronised to UTC time. The satellites continuously broadcast time and position information. The time and position information can be obtained worldwide with a GPS receiver and antenna. GPS works continuously in any whether conditions, anywhere in the world. Additionally, there is no set up fee or subscription charges to utilise the GPS systems. Many computer timing systems and NTP Server systems utilise GPS as an accurate external timing reference. GPS timing is generally much more accurate than radio based timing references.
Computer Time Synchronisation
Accurate computer time synchronisation can be achieved by combining a GPS or Radio timing receiver with a RS232 or USB interface. Software drivers can then be installed on the host PC to obtain accurate time and synchronise the host PC’s system time. Most PC operating systems can be synchronised, including Microsoft Windows 2000, 2003 and XP, LINUX, UNIX and Novell. In many cases, the host PC’s system time can be synchronised to within a few microseconds of the correct time.
Network Time Synchronisation
The standard protocol for achieving computer network time synchronisation is the Network Time Protocol (NTP). NTP is the standard way of distributing time around the Internet and other networks. Stratum 1 NTP servers obtain time from an external timing reference, such as GPS, MSF-60, DCF-77 or WWVB. The external time reference is then used to synchronise the NTP server system time. The synchronised system time is then used by the NTP Server to distribute accurate time to network time clients over an IP network. NTP operates in a hierarchical manner; lower stratum NTP servers obtain time from higher stratum devices.
NTP server systems can synchronise to within a few microseconds of the correct time. Depending on network traffic, NTP time clients can synchronise to within a few milliseconds of a NTP server.
About the Author
Dave Evans develops atomic clock time synchronisation systems to ensure accurate time on PC’s and computer networks. Click here to find out more about GPS NTP Server and Atomic Clock systems.
Posted in 
Tags: