Siemens SICLOCK TC 400 - Manual (Page 79)

Parameterization
9-77 © Siemens AG 2007 All Rights Reserved
SICLOCK
® TC 400
9.1.2 Operation as NTP client
Four IP addresses of NTP servers can be assigned for SICLOCK TC 400 as NTP
client.
The servers are polled regularly and, on the basis of a strict selection strategy, a
preferred server is selected.
For the strategy when a server fails, see Redundancy (Section 2.6).
NTP client
You can activate the client service with the /NTP Client/NTP Client (0.18.01)
parameter.
IP address of the NTP servers
Four IP addresses of the NTP servers can be assigned with the /NTP Client/NTP
Server List[4] (0.18.02) parameter. Address 0.0.0.0 means that no server has
been entered.
DNS names are not supported.
Current NTP server
The /NTP Client/Active Server (0.18.03) parameter displays the currently
selected NTP server. Address 0.0.0.0 means that no server has been entered.
Monitoring the servers
The /NTP Client/Monitoring/monitor server (0.18.04) parameter can be used to
set up the monitoring of the NTP servers.
9.1.3 Redundancy
The preference when an external synchronization fails depends on the setting of
the /Redundancy/Redundancy (0.09.10) parameter:
• "Master (prefer radio clocks to NTP)" setting
− RADIO CLOCK 1 is always accepted.
− RADIO CLOCK 2 is used when RADIO CLOCK 1 is not available.
− NTP is used when RADIO CLOCK 1 and RADIO CLOCK 2 are not avail-
able.
• "Slave (prefer NTP to radio clocks)" setting
− RADIO CLOCK 1 is used when NTP is not available.
− RADIO CLOCK 2 is used when NTP and RADIO CLOCK 1 are not avail-
able.
− NTP is always accepted.