Filtering Of The System Events; Time-Of-Day Synchronization - Siemens S7-1500 Operating Instructions Manual

4.4.4

Filtering of the system events

Communications problems if the value for system events is set too high
If the value for filtering the system events is set too high, you may not be able to achieve the
maximum performance for the communication. The high number of output error messages
can delay or prevent the processing of the communications connections.
In "Security > Log settings > Configure system events", set the "Level:" parameter to the
value "3 (Error)" to ensure the reliable establishment of the communications connections.
4.5

Time-of-day synchronization

General rules
The CP supports the following mode for timeofday synchronization:
● NTP mode (NTP: Network Time Protocol)
Note
Recommendation for setting the time
Synchronization with a external clock at intervals of approximately 10 seconds is
recommended. This achieves as small a deviation as possible between the internal time
and the absolute time.
Note
Special feature of time-of-day synchronization using NTP
If the option "Accept time from non-synchronized NTP servers" is not selected, the
response is as follows:
If the CP receives a time of day frame from an unsynchronized NTP server with stratum
16, the time of day is not set according to the frame. In this case, none of the NTP
servers is displayed as "NTP master" in the diagnostics; but rather only as being
"reachable".
Security
In the extended NTP configuration, you can create and manage additional NTP servers.
Note
Ensuring a valid time of day
If you use security functions, a valid time of day is extremely important. If you do not obtain
the time-of-day from the station (CPU), we therefore recommend that you use the
NTP (secure) method.
CP 1543-1
Operating Instructions, 05/2017, C79000-G8976-C289-07
Configuration, programming
4.5 Time-of-day synchronization
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