Ross SRG-2200, User Manual

Page: 85 / 96

SRG-2200 User Guide (v6.0) NTP Option • 85
NTP Option
This chapter provides information on installing the NTP option for your SRG-2200.
Overview
The SRG-2200 always contains the hardware, software and associated circuitry necessary to allow operation of the
NTP Option.
An Option Key is used to enable the NTP Option (refer to the section “
Options Tab ” on page 53 for details). No
additional externally connected hardware is required as part of the installation. A power cycle may be required to
complete the update process.
In order to utilize the NTP Option, simply use an Ethernet cable to connect the SRG-2200 to your local network
device (master router or local hub).
Follow the instructions in the section “
Network Tab ” on page 52 and “ NTP Time (from Server) Tab ” on page 48
to configure the Network and NTP systems with your required parameters.
Background Information
A good source of reference time is the Network Time Protocol available on most commercial Ethernet networks.
Note: No frequency or phase can be accurately inferred from the NTP system.
The SRG-2200 NTP system can only be configured as a NTP Client where the SRG-2200 requests time from a NTP
server.
NTP Client
As the SRG-2200 is powered, the NTP Client begins requesting time from the designated remote NTP server. The
NTP Client will keep searching for a time until it gets one.
The NTP operational parameters can be monitored in the LCD menu, and on the Dashboard remote control
program.
Default Settings
The default settings of the NTP system are as follows:
• SPG IP address 192.168.001.044
• SPG IP mask 255.255.255.000
• SPG IP Gateway 192.168.001.254
• Remote NTP Server IP address 139.143.005.030.
Time Locking
Time lock is achieved by reading the NTP time from the NTP Server and calculating an appropriate time-code. NTP
locks the SRG-2200 central timing system.
Keep the following mind:
• The time-code needs to be checked and updated each time the NTP Server is detected.
• However in marginal networks the “question-response” message times may be so variable the time-code update
should be suppressed until it has been valid for a number of seconds.
• Once the time-code has been set by the NTP Client, the SRG-2200 should not need to re-check the NTP time
unless a crash lock has been forced by the phase locking arrangement.