Example: Configuring The Ntp Server - Siemens SIMATIC S7-1500 System Manual

Principle of operation
In NTP mode, the device sends time queries at regular intervals (in client mode) to the NTP
server in the subnet (LAN). Based on the replies from the servers, the most reliable and most
accurate time is calculated and the time of day on the S7-1500R/H CPU is synchronized. The
advantage of this mode is that it allows the time to be synchronized across subnets. You can
synchronize the time of day of up to a maximum of four NTP servers. You address a
communications processor or an HMI device, for example, as sources for time
synchronization via the IP addresses.
The update interval defines the interval between the time queries (in seconds). The value
range for the interval is 10 seconds to one day. In NTP mode, it is generally UTC (Universal
Time Coordinated) that is transferred. UTC corresponds to GMT (Greenwich Mean Time).
Conditions
• In the S7‑1500R/H redundant system, you need to configure time synchronization in NTP
mode for each CPU individually. If possible, use the same settings for both CPUs.
• You define the settings for the time synchronization via NTP method in the "Properties >
General > Time" parameter group.
• Make sure that the primary CPU maintains a constant connection to the NTP server. The
backup CPU then receives its synchronized time of day from the primary CPU.
Procedure
Proceed as follows to enable time synchronization for a CPU:
1. Configure the interface properties in the "Properties > General > Time" parameter group.
2. Set the "Set NTP server in project" value at the "Time synchronization" parameter.
3. Enter the IP addresses of up to four NTP servers at parameter "Server 1-4".
4. Set the time interval for time queries at the parameter "Update interval".
11.7.1

Example: Configuring the NTP server

Configuring time synchronization with your own NTP server
Automation task
You use your own server in your network. Your own server offers the following advantages:
• Protection against unauthorized external accesses
• Every device that you synchronize with your own NTP server uses the same time.
You want to synchronize the CPUs of your S7-1500R/H redundant system with this NTP
server.
Conditions and parameters
• You have your own NTP server in your network with the IP address 192.168.1.15.
• S7-1500R/H redundant system
S7-1500R/H redundant system
System Manual, 11/2022, A5E41814787-AD
Commissioning
11.7 Time synchronization
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