Configuration
4.4 Basic communication mechanisms
CP 1243-8 IRC
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Operating Instructions, 02/2018, C79000-G8976-C385-03
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Address of the master
–
IP address
or
–
Name that can be resolved with DNS
If you use DNS, there must be a DNS server (see below) and this must be reachable
for the CP.
●
Port number of the listener port of the master
●
DNS server address(es)
You require the DNS server address if you address the master using a name that can be
resolved by DNS.
Redundant DNP3 or IEC master
The two devices of a redundant master have an identical station address with both protocols.
They only require different IP addresses or host names.
Configurations with connections over the Internet: VPN connections
For connections running via the Internet, dynamic IP addresses can be used.
To allow communication in both directions and to ensure that the data is protected during
transfer, a connection with a VPN tunnel is necessary. For this the security modules of the
SCALANCE S or SCALANCE M series are available.
Remember the following points when configuring:
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You configure the master IP address as normal.
●
When configuring the CP interface, configure the IP address of the router.
●
You create the VPN configuration with SCALANCE S/M both for the station end and for
the control center end in STEP 7.
4.4.2
Connection establishment
Connection establishment with telecontrol communication
With telecontrol communication the CP always establishes a connection.
DNP3 / IEC
With the DNP3 and IEC protocols, connection establishment by the CP is instigated by the
master (polling).
With the DNP3 protocol by configuring the Transmission mode "Spontaneous" in the
parameter group "Transmission settings" of the Ethernet interface the unsolicited transfer of
data by the CP can be released.
