Siemens SIMATIC ET 200AL - Secure OUC between Two S7-1500 Cpus

Open User Communication
6.11 Secure Open User Communication
Communication
98 Function Manual, 12/2017, A5E03735815-AF
Additional information
You can find more information about the system data types TCON_QDN_SEC in the STEP 7
online help.
For additional information on secure communication, refer to the section Secure
Communication (Page 36).
6.11.3
Secure OUC between two S7-1500 CPUs
The following section describes how you can set Secure Open User Communication via TCP
between two S7-1500 CPUs. In the process one S7-1500 CPU acts as TLS client (active
establishing of the connection) and the other S7-1500 CPU as TLS server (passive
establishing of the connection).
Setting up a secure TCP connection between two S7-1500 CPUs
For secure TCP communication between two S7-1500 CPUs you need to create a data
block with the TCON_IPv4_SEC system data type yourself in every CPU, assign parameters
and call it directly at the one of the instructions TSEND_C, TRCV_C or TCON.
Requirements:
● Current date and time are set in the CPU.
● Both S7-1500 CPUs have at least firmware version V2.0
● TLS client and TLS server have all the required certificates.
Figure 6-18 Certificate handling for Secure OUC between two S7-1500 CPUs