Electronic clocks control critical functions in many applications. However, clocks are often designed for low cost rather than for keeping accurate time.
Even fairly accurate computer clocks are likely to vary due to manufacturing defects, changes in temperature, electric and magnetic interference, the age of the quartz crystal, or even system load. Additionally, even the smallest errors in keeping time can significantly add up over a long period. Consider two clocks that are synchronized at the beginning of the year, but one consistently takes an extra 0.04 milliseconds to increment itself by a second. By the end of a year, the two clocks will differ in time by more than 20 minutes. If a clock is off by just 10 parts per million, it will gain or lose almost a second a day.
Synchronization to GPS
The GPS system (also called NAVSTAR) includes 24 satellites each with three or four onboard atomic clocks. The US Naval Observatory monitors the satellite’s clocks and sends control signals to minimize the differences between them and a master atomic clock for accuracy and traceable to national and international standards (known as UTC).
For time synchronization, the GPS signal is received, processed and distributed by a device or instrument called a master clock, time server, or primary reference. The time is "slaved" to other devices, systems, or networks so their "local clocks" are likewise synchronized to UTC. Typical accuracies range from better than 500 nanoseconds to a few milliseconds depending on the synchronization protocol.
GPS clock synchronization eliminates the need for manual clock setting (an error-prone process) to establish traceability to national and international standards so various events can be correlated even when they are time-stamped by different clocks. The benefits are numerous and include: legally validated time stamps, regulatory compliance, secure networking, and operational efficiency.
Products for GPS clock synchronization
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SecureSync® Synchronization Systems
A combination of Spectracom's precision master clock technology and a compact modular hardware design for a flexible and powerful time & frequency reference system. Military and commercial applications alike will benefit from its extreme reliability, security and flexibility for synchronizing critical operations.
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Bus-Level Timing
Synchronize one or more computer- or instrument chassis-based system to a time code, providing accurate timing, time stamps for external events, time-based interrupts, and timing and frequency reference signals to other devices. Spectracom's TSync, TPRO and TSAT timing cards easily integrate into PCs and Servers (PCI and PCI express) and instrument and other interfaces (cPCI, PMC, PC104, IP).
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NetClock Time Server
For over three decades, Spectracom has been a leader in providing Legally Traceable Time® solutions to meet the timeserver needs of the most vital time synchronization applications.The 9400 series NetClock® network time servers deliver worldwide, split-second timing to mission critical systems.
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Synchronized Clock Displays
Accurate time is an integral part of a facility's communication system in many industries and applications. Virtually every enterprise benefits from synchronized time displays - clocks displaying the correct time that is traceable to official time. Spectracom offers three types of display clocks for truly synchronized operations. All display clocks utilize a NetClock network time server as the system's master clock.
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Timing Modules
In situations where a rack mount synchronization instrument is not desirable, a timing module reduces the speed and cost of implementation. For developers of transmitters and other devices that require built-in GPS synchronization signals, Spectracom offers two styles of easy-to-integrate solutions: The Epsilon Board™ OEM, EB03 and the Epsilon GPS Clock, model EC1S.
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