6.4
Open User Communication with addressing via domain names
As of firmware version V2.0, S7-1500 CPUs, ET 200SP CPUs and the CPU 1516pro-2 PN
support Open User Communication with addressing via Domain Name System (DNS). A
DNS client is integrated in the CPU. In the case of communication via DNS, you use domain
names as an alias for IP addresses to address communication partners. Addressing of the
communication partners via domain names is possible for open communication via TCP and
UDP.
At least one DNS server must be located in your network as a requirement for
communication via DNS.
The S7-1500 software controller supports communication via DNS for all interfaces that are
assigned to the software controller.
Setting up communication via DNS
The DNS client of the CPU must know the IPv4 address of at least one DNS server so that a
CPU can establish a connection to a communication partner via its domain name. The CPU
supports up to 4 different DNS servers.
To set up communication via domain names for an S7-1500 CPU, follow these steps:
1. Select the CPU in the network view of STEP 7.
2. In the Inspector window go to "Properties" > "General" > "DNS configuration".
3. Enter the IPv4 address of a DNS server in the "DNS server addresses" column of the
"Server list" table.
You can enter up to 4 IPv4 addresses of DNS servers.
Figure 6-1
Entering DNS server addresses using a CPU 1516-3 PN/DP as an example
Communication
Function Manual, 12/2017, A5E03735815-AF
6.4 Open User Communication with addressing via domain names
Open User Communication
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