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 their atomic clocks and a master atomic clock for accuracy and traceable to national and international standards (known as UTC).
For time synchronizing a clock, the GPS signal is received and distributed by a master clock, time server, or primary reference source to a device, system, or network so the local clocks are synchronized to UTC. Typical accuracies range from better than 500 nanoseconds to 1 millisecond anywhere on earth.
The GPS clock synchronization eliminates the need for manual clock setting (an error-prone process). The benefits are numerous and include: legally validated time stamps, regulatory compliance, secure networking, and operational efficiency.
Synchronizing:
- Computer clocks (servers and workstations)
- Network devices (routers, switches, firewalls)
- Telecommunications networks (PBXs, MUXs, SONET networks, wireless systems)
- Critical devices and networks (9-1-1 centers, command and control operations, military test ranges, radar systems, time displays)
- Physical security systems (video, building access controls, networks)
- IT security systems (cryptography, authentication, encryption)
- Facility wall clocks
Products for GPS clock synchronization
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Network Time Servers
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NetClock/GPS systems provide reliable and secure timing to networks and critical devices for command centers and secure data networks. Provides NTP for ethernet networks, plus IRIG, serial time codes, 1 PPS and 10 MHz outputs when needed.
Features: GPS synchronization for networks and devices
Benefits: Secure, stratum-1 accuracy, easy-to-manage |
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Master Clocks
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NetClock TIme Server and Epsilon GPS Clock systems are used as master clocks in a variety of applications. Serial time codes, NTP, IRIG, 1 PPS and 10 MHz outputs are based on GPS disciplined internal oscillators (choice of TXCO, OXCO, and Rubidium).
Features: GPS synchronization for networks and devices
Benefits: Secure, stratum-1 accuracy, easy-to-manage |
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Primary Frequency References
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Ageless master oscillators and Epsilon GPS clocks are highly accurate frequency and timing sources locked to GPS. Use as site references for communications systems or for calibrating time and frequency instruments and devices.
Features: Oscillator options, precision timing outputs
Benefits: Stratum-1 accuracy, stability |
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Time Displays
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TimeView® and NetClock® WiSync time displays are synchronized from a GPS-enabled time source using RS-485 or a wireless transmission. Options include choice of analog or digital. Also options for event and alert indicators.
Features: Wireless time, high visibility, Synchronized time
Benefits: Operational efficiency |
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Bus-Level Timing Boards
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Integrate time synchronization into embedded systems with bus-level timing. Utilize your IRIG or other precision time code, or use GPS to synchronize your system. All major bus-types and operating systems are supported.
Features: Timecode input, timecode output, GPS timing
Benefits: Accurate, user-programmable, multi-functional, versatile, customizable |