Secure Ouc With Modbus Tcp - Siemens SIMATIC ET 200AL System Manual

6.11.5

Secure OUC with Modbus TCP

For secure Modbus TCP connection you need to create a data block with one of the system
data types TCON_IP_V4_SEC or TCON_QDN_SEC yourself, assign parameters and call it
directly at the MB_Server or MB_CLIENT instruction.
Requirements:
● S7-1500 CPU CPU firmware version V2.5 or higher
● The Modbus client (TLS client) can reach the Modbus server (TLS server) over IP
communication in the network.
● TLS client and TLS server have all the required certificates.
Example of setting up a secure Modbus TCP connection to a Modbus TCP server
The following section describes how you can set up a Secure Open User Communication
over Modbus TCP from a Modbus TCP client to a Modbus TCP server.
To set up a secure connection from a Modus TCP client (TLS client) to a Modbus TCP
server (TLS server) and set up the IPv4 address of the mail server, follow these steps:
1. Create a global data block in the project tree.
2. Define a tag of the data type TCON_IP_V4 SEC in the global data block.
Figure 6-25 TCON_IP_V4_SEC
3. Set the connection parameters of the TCP connection in the "Start value" column. Enter
the IPv4 address of the mail server, for example, for the "MailServerAddress".
Communication
Function Manual, 12/2017, A5E03735815-AF
Open User Communication
6.11 Secure Open User Communication
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