Siemens SIMATIC S7-400 Operating Instructions Manual page 71

Certificate validation
Here you set the options for checking the certificates of the communications partners for the
UA server function of the CP.
● Check certificates
The CP always checks the certificate of the communications partner.
If the partner certificate is invalid or is not trustworthy, communication is aborted.
● No strict certificate validation
If the option is enabled, the CP allows communication in the following situations:
– The IP address of the communications partner is not identical to the IP address in its
– The use stored in the certificate (OPC UA client/server) differs from the function (OPC
– The current time on the CP is outside the period of validity of the partner certificate.
Regardless of these exceptions, to establish a connection, at least the following
requirements must be met:
– The application URI sent by the requesting client must match the URI of the server
– If the partner certificate is not trustworthy, the CP must at least have stored a self-
– If the partner certificate was issued by several CAs, all CAs must be saved in the
● Do not check period of validity
If the option is enabled, the CP checks the certificate of the communications partner. The
CP also allows communication in the following situation:
– The current time on the CP is outside the period of validity of the partner certificate.
If none of the options is enabled, no certificates are checked.
Note the information in the section Handling certificates (Page 73) on the establishment of
communication.
OPC UA client
OPC UA client
● OPC UA client
Enable this option to enable the function of an OPC UA client on the CP.
You specify the remaining settings for the client function using the program blocks FB230 to
FB236 of the library "SIMATIC_NET_CP" see section Programming the OPC UA client
blocks (Page 79).
CP 443-1 OPC UA
Operating Instructions, 01/2017, C79000-G8976-C427-02
certificate.
Note: The OPC UA server does not check the IP address of the communications
partner (client).
UA client/server) of the communications partner.
application of the CP.
signed certificate of the partner.
certificate store of the CP.
4.8 Configuration of the CP in STEP 7 Professional
Configuration and operation
71