Inputs And Outputs; General Information About Gps And Gnss; Spectracom Format - Spectracom SecureSync User Reference Manual

SecureSync combines Spectracom's precision master clock technology and secure network-cent-
ric approach with a compact modular hardware design to bring you a powerful time and frequency
reference system at the lowest cost of ownership. Military and commercial applications alike will
benefit from its extreme reliability, security, and flexibility for synchronizing critical operations.
An important advantage of SecureSync is its unique rugged and flexible modular chassis that can
be configured for your specific needs. Built-in time and frequency functions are extended with up to
six input/output modules.
Included with the base unit is an extremely accurate 1PPS timing signal aligned to a 10 MHz fre-
quency signal. A variety of internal oscillators is available, depending on your requirements for hold-
over capability and phase noise. Choose from a variety of configurable option cards, each with an
assortment of input/output timing signal types and quantity, including additional 1PPS, 10 MHz,
timecode (IRIG, ASCII, HAVE QUICK), other frequencies (5MHz, 2.048 MHz, 1.544 MHz,
1MHz), Precision Timing Protocol (PTP) input/output, multi-Gigabit Ethernet (10/100/1000Base-
T), telecom T1/E1 data rates and multi-network NTP, allowing SecureSync to be customized for
your exact requirements.
To support network time synchronization, SecureSync supports the latest features of Network
Time Protocol (NTP). An optional multi-port NTP configuration allows for operation across four
LAN segments or shared operation between up to four separate/isolated networks.
1.3

Inputs and Outputs

SecureSync provides multiple outputs for use in networked devices and other pieces of tech-
nology. A 1-Pulse-Per-Second (1PPS) output acts as a precise metronome, counting off seconds
of System Time in the selected timescale (such as UTC, TAI or GPS). A 10 MHz frequency ref-
erence provides a precise, disciplined signal for control systems and clocks (as the inverse of time
is frequency). SecureSync's outputs are driven by its inputs – most significantly, Global Navigation
Satellite System (GNSS) technology as well as IRIG input from IRIG signal generators (such as
Spectracom's NetClocks and bus- level timing boards) and other available input references.
GNSS-equipped SecureSyncs can track up to thirty-two GNSS satellites simultaneously and syn-
chronize to the satellite's atomic clocks. This enables SecureSync-equipped computer networks
to synchronize all elements of network hardware and software (including system logs) over LANs
or WANs – anywhere on the planet.
1.4

General Information about GPS and GNSS

The United States government operates a set of approximately 32 satellites, collectively known as
the "GPS Constellation" or "GPS Satellites." Each satellite has an internal atomic clock and trans-
mits a signal specifying the time and satellite position. On the ground, the GPS receiver determ-
ines its position (longitude, latitude and elevation) and the time by decoding the signals
simultaneously from at least four of the GPS satellites. Each satellite transmits a CDMA signal in
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1 SecureSync User Reference Guide Rev. 18
NOTE – All features described are not available on all SecureSync variants.
1.3 Inputs and Outputs
3