LEGRAND Raritan PX3TS User Manual page 394

Chapter 7: Using the Web Interface
374
Windows NTP Server Synchronization Solution
The NTP client on the PX3TS follows the NTP RFC so the PX3TS rejects any NTP
servers whose root dispersion is more than one second. An NTP server with a
dispersion of more than one second is considered an inaccurate NTP server by
the PX3TS.
Note: For information on NTP RFC, visit
http://tools.ietf.org/html/rfc4330
Windows NTP servers may have a root dispersion of more than one second,
and therefore cannot synchronize with the PX3TS. When the NTP
synchronization issue occurs, change the dispersion settings to resolve it.
To change the Windows NTP's root dispersion settings:
1. Access the registry settings associated with the root dispersion on the
Windows NTP server.
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\Co
nfig
2. AnnounceFlags must be set to 0x05 or 0x06.
▪
0x05 = 0x01 (Always time server) and 0x04 (Always reliable time
server)
▪
0x06 = 0x02 (Automatic time server) and 0x04 (Always reliable time
server)
Note: Do NOT use 0x08 (Automatic reliable time server) because its
dispersion starts at a high value and then gradually decreases to one
second or lower.
3. LocalClockDispersion must be set to 0.
http://tools.ietf.org/html/rfc4330 -
to refer to section 5.