System network
In the system network the IP address 192.168.214.xxx with subnet mask 255.255.255.0 is pre-
selected. Here there is precisely one DHCP server with DNS that can run on one NCU or one
PCU. The server ensures assignment of IP addresses to the Ethernet components in the
system network (DHCP clients) from a specified address band.
The following rules apply for assignment of IP addresses in the system network:
● For all NCUs and PCUs the commissioning engineer assigns fixed IP addresses in the
associated address bands, as well as appropriate computer names (host names). All other
(operator) components are automatically assigned an IP address from the DHCP server.
Its name is generated automatically (for MCP, MPP, HT 8), or is entered at commissioning
(TCU).
● If there are multiple NCU and/or PCU in the system network the system automatically
(depending on the start-up sequence) specifies the DHCP server and automatically ensures
synchronization of all necessary data so that the next time the system boots any other NCU
or PCU could take on the role of DHCP server. However it is a good idea to specify a DHCP
master. This is an NCU or PCU in the system network that is available at each system boot
and which regularly takes over the task of the DHCP server and DNS server.
Synchronization of data takes place in any event so that any other NCU or PCU can take
over this task. All non-master NCU / PCU wait in the system boot an adjustable length of
time for availability of the master.
Note
In a system network, on a boot server respectively - i.e. the NCU or PCU which
accommodates the active DHCP server - a maximum of 30 operator stations may be
operated simultaneously with a TCU.
A maximum of 10 operator stations with a TCU may connect up simultaneously with the
same HMI application when powering up.
Connection to a company network
Each NCU can be connected via X130, and each PCU can be connected via "Ethernet 1" to
the company network. The company network is used to exchange operating software with
servers or to execute part-programs directly from servers in the company network. Company
network and system network should always be logically and also physically separated.
Service interface X127
The service interface X127 of the NCU is used for direct connection of a PG/PC for service
purposes. Here access with STEP 7 to the PLC, and with NCU 7x0.3 PN also to PROFINET
is possible.
With direct connection (peer-to-peer) of a PG/PC to X127 it is absolutely necessary that the
PG is operated as a DHCP client.
General information and networking
1.4 Networking
Operator panel front: OP 010
Manual, 07/2018, A5E36371538B
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