Symmetricom XLi IEEE 1588 Clock User Manual


 
XLi IEEE 1588 Clock 15
997-01510-03, Rev. C, 12/12/2006
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3: Installation and Set-up
In a nutshell:
Install the GPS antenna outdoors, run the cable, and connect it to the XLi’s GPS receiver.
Make the following connections to the XLi (all cables supplied):
- From the network to the NET port (for access to the command line and web interfaces).
- From an AC outlet to the XLi’s AC power supply.
Configure the network settings of the XLi’s standard network port.
Configure the network settings of the XLi’s IEEE 1588 network port.
Installing the GPS Antenna
Precise Time Protocol (PTP) grandmasters are typically synchronized to International Atomic Time (TAI).
To accomplish this, the user sets up the GPS antenna, connects it to the GPS receiver in the XLi IEEE
1588 Clock, and configures GPS as its primary reference source. When the XLi IEEE 1588 Clock locks
to the GPS reference source, it computes TAI and synchronizes the PTP grandmaster (the IEEE 1588
card). When the PTP grandmaster is synchronized to the XLi IEEE 1588 clock it starts operating,
sending out PTP Sync and Follow_Up messages and responding to PTP requests.
Selecting a GPS Antenna Site
Select a site outdoors that...
Is the highest point available
Offers a full 360° view horizontally, to within 10° vertically of the horizon
Is higher than neighboring buildings/obstructions
Is protected from strong radio frequency (RF) and microwave transmissions
Is set away from RF-reflective surfaces that cause multipath interference
Is set 3 ft. (1 m) away from other GPS antennas
Is within the maximum GPS antenna cable length from the XLi
Typically, this site is on the roof of the building.
Avoid...
Mounting the antenna between tall buildings or next to walls and equipment
Exceeding the maximum cable-lengths specified for a particular cabling arrangement.
Patching multiple cables together to make a single cable run
Running the cable through bulkheads and along side high-energy cables
Crimping or damaging the cable
Mounting within 15 meters/yards of lightning rods, tower, or structures that attract lightning