Siemens SIMATIC ET 200AL, System Manual

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Communications services
3.6 Secure Communication
Communication
Function Manual, 05/2021, A5E03735815-AJ
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Settings at the TLS client
To set up a secure TCP connection in the TLS client, 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.
The example below shows the global data block "Data_block_1" in which the tag "SEC
connection 1 TLS-Client" of the data type TCON_IP_V4_SEC is defined.
Figure 3-25 IP_V4_SEC_Client
3. Set the connection parameters of the TCP connection in the "Start value" column. For
example, enter the IPv4 address of the TLS server for "RemoteAddress".
Note
Connection parameter Interface ID
Note that you can enter the value " 0 " for the interface ID in the data type
TCON_IP_V4_SEC. In this case, the CPU itself searches for a suitable local CPU interface.
4. Set the parameters for secure communication in the "Start value" column.
– "ActivateSecureConn": Activation of secure communication for this connection. If this
parameter has the value FALSE, the subsequent security parameters are irrelevant. You
can set up a non-secure TCP or UDP connection in this case.
– "TLSServerCertRef": Enter the value 2 (reference to the CA certificate of the TIA Portal
project (SHA256) or the value 1 (reference to the CA certificate of the TIA Portal project
(SHA1)). If you use a different CA certificate, enter the corresponding ID from the
certificate manager of the global security settings.
– "TLSClientCertRef": ID of the own X.509-V3 certificate.