Symmetricom XLi IEEE 1588 - Manual (Page 9)

XLi IEEE 1588 Clock 1
997-01510-03, Rev. C, 12/12/2006
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1: Overview and Features
Overview
Description
The standard XLi IEEE 1588 Clock, also referred to as the “XLi”, provides a complete implementation of
a Precise Time Protocol (PTP) “ordinary clock” over a dedicated IEEE 1588 card. The IEEE 1588 card
can be configured to operate as a PTP grandmaster or as a PTP slave.
As a PTP grandmaster, the IEEE 1588 card typically synchronizes PTP slaves on the network to
International Atomic Time (TAI). The XLi IEEE 1588 Clock derives TAI from the Global Positioning
System (GPS). In addition, Symmetricom designed the XLi IEEE 1588 Clock so the user can distribute
Coordinated Universal Time (UTC) or user-entered time over PTP.
As a PTP slave, the IEEE card automatically discovers a PTP master within its subnet/subdomain and
synchronizes to it. The PTP slave in turn, can be configured as the primary reference source for the XLi
IEEE 1588 Clock (the clock synchronizes to the PTP slave).
The XLi’s Time Interval/Event Time (TIET) feature can be used to measure PTP synchronization across
timing networks. For example, to measure a PTP slave’s synchronization to the PTP grandmaster, the
user connects the PPS output of a PTP slave to the XLi IEEE 1588 Clock and configures F110 to display
the time interval between each PPS.
See F130 - Precision Time Protocol Status (page 116) and F131 - Precision Time Protocol Network
Config (page 119) for more information.
Standard Configuration
The XLi IEEE 1588 Clock can be purchased in two configurations. The first configuration includes one
IEEE 1588 card preconfigured as a PTP master and located in Option Bay 4. The second configuration
has an additional IEEE 1588 card preconfigured as a PTP slave located in Option Bay 2. Both
configurations include the following items.
• XLi chassis and CPU card running special firmware
• The IEEE 1588 card(s)
• GPS C/A Receiver (87-8028-2)
• L1 GPS Antenna
• GPS antenna cable: 50 ft. (15.24 m) of RG-59
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• Time Interval Event Time (TIET)
• Standard 110 VAC Power Supply
• Standard TCVCXO Oscillator
1. Other GPS antenna cable lengths can be specified at the time of purchase.