GPS Clock Synchronization For Computer Networks Using NTP

Computers have real-time-clock chips that utilize the same timing components as wrist watches. This being the case, the time they keep drifts away from the correct time in exactly the same way. This drift can be attributed to slight changes in temperature or manufacturing tolerances. However, they all add up to the time diverging away at differing rates. A number of computers set to the correct time at the same moment will within a few weeks each differ by multiple seconds or even minutes in the worst cases.

Correctly Ordered Events on a Computer Network

In an environment, such as a network, where transactions are being processed or events logged on multiple computers, time drift can cause all sorts of problems. Without the system time of each computer being synchronized to one another, time-stamps and events will appear to arranged in an ad hoc manner with no predetermination. For most organizations, this is completely unacceptable. A means of providing a network with an accurate time reference that all inter-operating computers can refer to is a must.

The Precision of the Atomic Clock

Atomic clocks are highly accurate devices that can provide time to within one second every one-million years. These devices are based on atomic physics. Since 1967, atomic clocks have been based on the International System of Units (SI) which has defined the second as an international standard. This is specified as the duration of 9192631770 cycles of radiation corresponding to the transition between two energy levels of the cesium-133 atom. These devices are large and very complex peices of equipment. They are also exorbitantly expensive. This is why they are only generally found in government laboratories, universities or high-end scientific labs. They are generally not for the common user.

However, there is an alternative that can provide accuracy approaching atomic clock standards without the associated cost. The Global Positioning System (GPS) is a constellation of 24 orbiting satellites. Each satellite contains an highly accurate atomic clock, which is synchronized with very high precision to atomic standards at the US National Institute of Standards and Technology (NIST).

TimeTools Products That Provide Accurate Time

SR and SC Series Network Time Protocol Servers

TimeTools SR and SC series of rack-mountable and compact GPS NTP servers provide a GPS or MSF \ DCF referenced, accurate source of time to a computer network. The appliance accepts either a GPS or a radio antenna, or indeed both, to obtain accurate time. The unit then uses the received time-stamps to synchronize its internal real-time clock to within microseconds of the correct time. It’s internal real-time clock can then provide network time clients such as servers and workstations, routers, switches, CCTV and DVR systems with an accurate time reference.

The Network Time Protocol (NTP) is used to disseminate accurate time around the network. Most modern operating systems have built-in NTP or SNTP functionality and only need to be pointed to the IP address of the time server in order to periodically synchronize.

TimeTools SR9210 NTP Server

Click here for more information about TimeTools SR Series NTP Time Servers.

Analog and Digital Ethernet Networked NTP Displays

A range of analogue and digital wall clocks synchronized using Network Time Protocol (NTP) over an Ethernet Network. The clocks are Power-over-Ethernet (IEEE 802.3af compliant) devices that take power as well as data from the network cable. This feature saves on potential installations costs, due to not requiring a the cabling and installation of mains spur where the clock is to be located. Power-over-Ethernet technology is commonly used by many network devices, including IP phones and network switches. It is a standard means of powering network devices, which compatible switches being easily available. The clocks can utilize either an internet based time reference, a local server or GPS-reference time server to provide an organization with an accurate display of time. A single time server can easily handle thousands of clocks.

Product Features

Synchronize automatically by using the NTP/SNTP protocol over a standard Ethernet network to a local server, local GPS time server or internet based time reference.
The clocks can be configured for DHCP or static IP addressing.
Power-over-Ethernet (IEEE 802.3af) compliant, no expensive mains spur installation required.
Single or Double sided mounting providing a clear display of time visible up to 50m.
Configurable time zone and daylight saving for world-wide maintenance-free operation. No manual intervention required to correct or adjust for daylight saving changes.

Digital Clock Features

4 digit and 6 digit models available displaying hours and minutes or hours, minutes and seconds.
Red or Green LED 7-segment display
100mm (4 inch) High Digits – Visible from over 50m (150 ft)
Available in aluminium, plastic and stainless-steel enclosures in various colors.


Ethernet Networked NTP Wall Clocks


How To Buy Our Products

TimeTools sell directly to you! Our products are generally available from stock and can be shipped world-wide. Contact us for a quotation, advice or to set up an account. We also accept credit card payments, including Visa and MasterCard. Alternatively, please feel free to contact one of our re-sellers in your region.

About TimeTools

TimeTools is a leading UK manufacturer of GPS time synchronization, NTP Time Servers, Synchronized Time Displays and Precision Timing Equipment. Since 2002, we have been providing timing equipment to high-profile companies world-wide.

ISO 9001 Accreditation

Quality and customer satisfaction is of paramount importance to us. TimeTools is an ISO 9001:2008 accredited company. ISO 9001 is an internationally recognized standard for quality management. TimeTools is also a member of the CE Marking Association. An organization which facilitates us with meeting our legal obligations with regards to CE Marking and product conformity for the sale of products within the EU. It also allows us to keep up-to-date with changes in EU legislation.

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