RuggedCom RSG2288 用户手册

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Installation 
2.9  Precision Time Protocol (PTP) Card and IEEE1588 v2 
The Precision Time Protocol (PTP) card option for the RSG2288 adds the ability 
to provide time synchronization via IRIG-B, and to synchronize to an external 
IRIG-B source or to the GPS network. The time synchronization capabilities of 
the RSG2288, both with and without the PTP card option, are summarized 
below: 
Synchronization Source 
Without PTP 
Card 
With PTP 
Card 
NTP 
 
 
IEEE 1588 v2 
 
 
IRIG-B PWM 
 
 
GPS  
 
Table 9: RSG2888 Time Synchronization Sources 
 
Synchronization Service 
Without PTP 
Card 
With PTP 
Card 
NTP 
 
 
IEEE 1588 v2 
 
 
IRIG-B AM 
 
 
IRIG-B PWM 
 
 
Table 10: RSG2288 Time Synchronization Services 
 
NTP (Network Time Protocol) is the standard for synchronizing the clocks of 
computer systems throughout the Internet and is suitable for systems that require 
accuracies in the order of 1 ms. 
IRIG-B (Inter Range Instrumentation Group, mod B) time synchronization is an 
even older, established, inter-device time synchronization mechanism providing 
accuracy on the order of 1ms to 1µs. 
The Global Positioning System (GPS), as a source of accurate time, requires an 
external GPS antenna input to provide accurate time signals on the order of 
500ns. The RSG2288 can use the GPS receiver on the PTP card to provide the 
time base for the system. 
IEEE 1588 is designed to fill a niche not well served by either of the two older, 
dominant protocols, NTP and IRIG-B. IEEE 1588 is designed for local systems 
requiring accuracies on the order of 100 nanoseconds. IEEE 1588 is also 
designed for applications that cannot bear the cost of a GPS receiver at each 
node or for which GPS signals are inaccessible. Every Ethernet port on the 
RSG2288 supports IEEE1588. 
The PTP card option is an ideal product for use in existing installations already 
well served by NTP, IRIG-B or GPS. It also provides a migration path for the use 
of the new IEEE 1588 v2 standard. As more end devices enter the market with 
IEEE 1588 compatibility this card provides an easy transition to this new time 
synchronization standard. 
 
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RSG2288 Installation Guide rev103