Siemens IE/PB LINK PN IO Operating Instructions Manual page 66

Configuration and operation
4.7 Time-of-day synchronization
Both in NTP and in the SIMATIC mode, the time-of-day is transferred as UTC (Universal
Time Coordinated).
With the SIMATIC mode you require a time master in a network.
If time-of-day synchronization is enabled in the configuration, you can set whether the LINK
simply adopts the time-of-day or adopts it and forwards it. The following options are
available:
● NTP
– Adopt the time of day
– Adopt the time of day and forward it to PROFIBUS
● SIMATIC mode
– Adopt the time of day from Ethernet (no forwarding to PROFIBUS)
– Adopt the time of day from PROFIBUS (no forwarding to Ethernet )
– Adopt the time of day from Ethernet and forward it to PROFIBUS
– Adopt the time of day from PROFIBUS and forward it to Ethernet
NTP mode
With the NTP method, the LINK sends time-of-day queries at regular intervals to one to four
NTP servers in the subnet (LAN).
● The update interval (synchronization cycle) specifies the interval between the time
queries.
● "Accept time from non-synchronized NTP servers" option
If the option is enabled, the LINK also accepts the time-of-day from non-synchronized
NTP servers with stratum 16.
If the option is disabled, the response is as follows: If the LINK 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".
66
Operating Instructions, 11/2017, C79000-G8976-C393-02
IE/PB LINK PN IO