Siemens Simatic RTU303xC Series Operating Instructions Manual page 35

● IP configuration
The essential features of IP configuration are as follows:
– VLAN interface and the WAN interface of the RTU support IP addresses according to
– Address assignment of the LAN interface
– Address assignment for the default router and DNS servers
● Time-of-day synchronization
The RTU has the following options for time-of-day synchronization:
– NTP
– By mobile wireless network
– By telecontrol master station
– GPS
For more information, refer to the section System time (Page 116).
For information on the format of the time stamp, refer to the section Overview (Page 178).
RTU303xC
Operating Instructions, 06/2019, C79000-G8976-C382-06
IPv4.
The IP address and the subnet mask can be set manually in the configuration.
The IP address can also be assigned automatically by the DHCP client function of the
RTU.
If the DHCP server function of the RTU is enabled, for the configuration PC to be
connected the IP address is assigned by the RTU in the network (normally the next
free address).
The addresses can be assigned manually or automatically with the DHCP client
function of the RTU. The RTU tells the DHCP server its own station name so that it
can register the name with its DNS server, if supported.
Time synchronization is carried out via SNTP (Simple Network Time Protocol).
Possible if the network provider supports the NITZ mechanism (Network Identity and
Time Zone).
If the RTU has a communications partner in the master station, it should always obtain
its local time of day from the partner.
In most cases, the time of day is transferred as UTC time.
When using the ST7 protocol the time of day is transferred as the local time of the
control center.
PCS 7 as master transfers the time of day with the DNP3 protocol as UTC and with
the IEC protocol as the local time of the PCS 7 PC.
Time-of-day synchronization can take place via GPS with RTU3031C .
Application and functions
1.8 Other services and properties
35