Time-Of-Day Synchronization - Siemens SIMATIC TeleControl DNP3 Configuration Manual

3.13

Time-of-day synchronization

Time-of-day synchronization and security
If you enable the security functions in modules with security, you will find the parameter
group under "Security".
When security functions are enabled, you need to regularly synchronize the time of day of
the communications module.
Basics of time-of-day synchronization
With telecontrol applications that require time-of-day synchronization, you need to
synchronize the time of day of the communications module regularly. If you do not
synchronize the time of day, there may be deviations of several seconds per day in the time
information of the stations.
The communications module can obtain the time of day from an external source (for the
methods see below) and forward the time of day to the station or the connected WAN
networks.
When an external time source is used, the connected S7 station can obtain the current time
of day both via the CPU and via a communications module (TIM, CP).
Note
Recommendation: Time-of-day synchronization only by 1 module
Only have the time of day of the station from an external time source synchronized by a
single module so that a consistent time of day is maintained within the station.
If the CPU takes the time from a communications module, disable time-of-day
synchronization of the CPU.
If you have the time synchronized on the communications module and on the CPU via NTP,
use the same NTP server to maintain a consistent time of day within the station if possible.
Time-of-day concept
Before configuring time-of-day synchronization, specify the following:
● Specify the time source in the network.
● Specify the time master in the network.
● Specify the network or networks via which the time of day will be forwarded by the time
master to the time slaves.
Configuration - DNP3
Configuration Manual, 11/2018, C79000-G8976-C508-01
Configuration
3.13 Time-of-day synchronization
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