Ronan X501NET - Manual (Page 26)

Chapter 2 - Interface
X501NET System Configuration Manual © 2008 Ronan Engineering Company 20
If the SNTP protocol is to be used to obtain time, the NTP Servers field must contain a list of
the TCP/IP addresses NTP servers. Up to four TCP/IP server addresses can be listed, separated
by semicolons.
2.6.3.2 Time Zone Field
The Time Zone field is used to add a signed offset to the time obtained through GPS or SNTP.
In the case of using IRIG-B for synchronization, the time is directly set without taking into
account the time zone.
2.6.3.3 NTP Acquisition Interval Fields
This field, NTP Acquisition Interval, and the following field, NTP Switch Timeout, are
used to control the frequency of polling the time server and the timeout after which to switch to
NTP in the case of the loss of a better quality time
17
source
18
(i.e. GPS or IRIG-B).
The NTP Acquisition Interval field is used to control how often (in seconds) an NTP server is
polled when that server is being used as the time source.
2.6.3.4 NTP Switch Timeout Field
The NTP Switch Timeout field is used to determine how long (in seconds) the X501NET will
wait after losing a higher quality time server before it starts to get time form an NTP server (also
see section 2.6.3.3).
2.6.3.5 Preferred Time Source Field
The Preferred Time Source field displays, and allows an Administer to change, the primary
time source to be used by the X501NET.
Preferred
Time
Source Description
None
No external time source is available, see the description of the
SetNV
Time button in section 2.6.1 for information on setting the internal
real-time clock.
GPS Use an external GPS receiver as the primary time source.
IRIG-B Use an external IRIG-B time code generator as the primary time source.
SNTP Use a network time server as the primary time source.
17 Higher accuracy or more reliable.
18 In many cases the X501NET MULTIPLEXER could temporarily lose the satellite connection (GPS) or the IRIG-
B synchronization and since the timing subsystem will continue to run on the last known good settings it is
undesirable to switch immediately to NTP. The default value is 60 seconds, but values up to one hour (3600 s) could
be acceptable.