Glossary
device to be reached. If the device is unreachable, the response is typically "request timed
out." If the device was reachable, the response is "reply from..." followed by various ping stat-
istics. The ping utility is available on the SyncServer's NETWORK - Ping page, and from the
command line on most operating systems. For more information, search the Internet for
"PING Man Page".
PTP (Precision Time Protocol
The Precision Time Protocol as defined in IEEE Std 1588-2008: IEEE Standard for a Pre-
cision
Clock Synchronization Protocol for Networked Measurement and Control Systems.
Stratum
This is an eight-bit integer that indicates the position of an NTP node within an NTP timing
hierarchy. It is calculated by adding 1 to the stratum of the NTP system peer.
For the SyncServer, the stratum values are defined as follows:
Stratum Definition
0 Hardware Clock when locked.
1 Primary server
2-15 Secondary server
16-255 Unsynchronized, unreachable.
For example, the SyncServer is:
n stratum 1 when the Hardware Clock (stratum 0) is synchronized to an input reference, in
holdover mode, or in freerun mode.
n stratum 2 through 15 when it is synchronized to a remote NTP server.
n stratum 16 when it is unsynchronized, indicating that it is searching for a valid source of
timing information.
The settings on the NTP - Prefs (on page 50) page affect stratum behavior.
Synchronizing NTP association
Synchronizing NTP associations are associations capable of providing time to the NTP dae-
mon. On the SyncServer, these are associations whose Role is server, peer, broad-
castclient, and multicastclient.
UTC
From Wikipedia: "Coordinated Universal Time (UTC) is a high-precision atomic time standard.
UTC has uniform seconds defined by International Atomic Time (TAI), with leap seconds
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