Operating instructions
Table Of Contents
- SICLOCK® TC 100 Plant Central Clock
- Overview
- Safety notices
- Preface
- Table of Contents
- 1 Safety instructions
- 2 Description
- 3 Hardware description
- 4 Operation planning
- 5 Mounting
- 6 Connection
- 7 Configuration Tool
- 8 Parameter assignment and operation of the device
- 9 Parameter assignment
- 10 Parameter table
- 11 Service and maintenance
- 12 Messages
- 13 Technical data
- 14 Dimension drawing
- 15 Circuit diagrams
- 16 Spare parts / accessories
- A Annex
- B ESD guidelines
- C List of icons
- D Glossary
- Index

Parameter assignment
9-7
© Siemens AG 2010 All Rights Reserved
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.