Siemens Plant Central Clock TC100 - Manual (Page 78)

Parameter assignment
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SICLOCK ® TC100 Operating Instructions
9.1.2 Operation as NTP client
Four IP addresses of NTP servers can be assigned for SICLOCK TC100 as an
NTP client.
The servers are queried regularly, and a preferred server is selected according to
a strict selection strategy.
For the strategy in the event of loss of server, see Redundancy (Chapter 2.6).
NTP Client
You activate the client service with the parameter
/NTP Client/NTP Client (0.18.01).
IP addresses of the NTP servers
You can specify four IP addresses of NTP servers with the parameter
/NTP Client/NTP Server List[4] (0.18.02). The address 0.0.0.0 indicates that no
server has been entered.
DNS names are not supported.
Current NTP server
The currently selected NTP server is displayed with the parameter
/NTP Client/Active Server (0.18.03). The address 0.0.0.0 indicates that no server
has been entered.
Monitoring the server
Monitoring of the NTP servers can be set up with the parameter
/NTP Client/Monitoring/Monitor Server (0.18.04).
9.1.3 Redundancy
The priority in the event of loss of an external synchronization is defined by the
setting of the parameter /Redundancy/Redundancy (0.09.10):
• Setting "Master (radio clocks preferred to NTP)"
− RADIO CLOCK is always accepted
− NTP is used when RADIO CLOCK is not available.
• Setting "Slave (NTP preferred to radio clocks)"
− RADIO CLOCK is used when NTP is not available.
− NTP is always accepted.