As of version 3.1.0 the SystemFW provides a SNTP Protocol implementation which can be used for time synchronization of PLC clock. It can be used as SNTP Client or / and SNTP Server. But only one instance of each can be executed at the same time on one PLC .
The SNTP server is listening only on the Ethernet interface, which the protocol is configured on. It is not possible to have an SNTP server on several Ethernet interfaces.
To read diagnosis information from the SNTP protocol within an IEC application the function block PmSntpInfo can be used. This Function block is part of the library ABB_Pm_AC500.lib. It can also be used to determine the synchronization state of the PLC clock.