Web Interface
Parity: (Odd, None, Even) The parity setting of the Sysplex Out port (should match that of the
receiving device).
Flywheel Quality Character:
The user can set the Flywheel Quality Character to:
n "" (space)
n "X"
n
"F" (for Flywheel Quality Character)
About Sysplex and the Hardware Clock
To achieve the highest levels of precision and accuracy, the Sysplex Timer port gets its time
directly from the Hardware Clock. The Hardware Clock synchronizes with the highest pri-
ority Input Reference (e.g. GPS, IRIG-B).
If an Input Reference becomes unavailable, and Holdover expires, the Hardware Clock syn-
chronizes to the time the NTP daemon gets from other synchronizing NTP associations (if
any are present). The default configuration includes three NTP servers on the Internet. If no
synchronizing NTP associations are present, the Hardware Clock is unsynchronized and
uses the internal oscillator to keep time.
The time quality character at the end of the Sysplex output string reflects the synchronization
state of the Hardware Clock. The user can select the time quality character used after hol-
dover expires and the hardware clock is:
n Synchronized to the NTP daemon, or
n Using the internal oscillator to keep time.
This setting is called the Flywheel Quality Character.
About the Flywheel Quality Character
The time quality character at the end of the Sysplex output string has three states:
n The first state is "X", time is invalid. The Hardware Clock has not yet synchronized to an
Input Reference.
n The second state is "" (space), time is valid. Hardware Clock has synchronized to an
Input Reference, or is in Holdover.
The third state is "F", the Flywheel Quality Character. The Hardware Clock has no Input
References and Holdover has expired.
The time quality character can progress through a number of states:
1. After the user starts the SyncServer, the Sysplex port starts outputting a time string. Ini-
tially, the time quality character is "X" (time invalid).
2. When the Hardware Clock locks to an Input Reference, the time quality character
becomes " " (time valid).
3. If the Hardware Clock loses all Input References and enters Holdover, the time quality
character remains " " (time valid).
4. If Holdover expires, the time quality character becomes the Flywheel Quality Character,
determined by the user.
Page 48..........................................................................997-01520-02 Rev. G2
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